Guy Holt

You can work in ratios, stops, or foot candles - which ever you are more comfortable with. Regardless which you use, the important thing is, as Stuart said in his post, "being able to pre-visualize lighting." In order to accomplish the look you are after, I would suggest you shoot a camera test. Using the methodology you plan to use (shoot raw and apply a look later, or shoot for the finished results in camera), test in a systematic fashion the effect of Key, Fill, Back Light, Kickers, Hair Lights, and Liners that are over and under exposure. For example, to test the effect of your key light on flesh tones, set your exposure with two doubles and a single in your key light. Then remove them a half stop at a time (without changing your camera exposure setting or exposure of the chip chart), and systematically note on a slate in the frame what you are doing. Once you have removed all the scrims, your flesh tone will be two and a half stops over exposed (since you have not changed the camera setting.) Put all the scrims back in and now, using single and double nets, systematically under expose the flesh tone in half stop increments (remember rotating a net relative to the light source will make it "fatter" or "thinner", which will enable you to "dial in" the exact level you want from the light.) Since you want to play on the lower register (based upon your sample), continue to under expose the flesh tone until it becomes a pure silhouette. Do the same for Fill, Back Light, Kickers, Hair Lights, and Liners in isolation and in specific combinations that you plan to use them in (for instance, in the opening shot of the sample, there is a delicate balance of back light to fill where both are well below a key tone level, and there are no other lights.) Having systematically tested each light, you can now see the effect that different levels of each has on the scene and can even use the test as a reference on set when lighting the scene. So that your eye does not compensate for the low light levels, you should put a fully exposed white reference in the frame (the white foam-core in the background of the pictures.) If you use a chip chart with variable gray steps form white to black, you will actually be able to see how tonal values are compressed and (block up or burn out) as you push them onto the “knee” or “toe” of your medium’s characteristic curve. For a good explanation on how to light a dark scene, see David Mullen’s excellent post at http://www.cinematog...howtopic=55891. In it he warns not to “make the classic mistake of assuming that a dark image involved working in low light levels.” To that I might add, “don’t Good Luck Guy Holt, Gaffer, New England Studios, Lighting and Grip Equipment Sales and Rentals in Boston.

Reversal film stocks (both 8mm & 16mm) are more like digital in the sense that they can dig deeper into shadow areas. If a negative stock has a nine stop range (five stops over before detail burns out, and four stops under before detail blocks up) a color reversal stock, like Kodachrome, will have a seven stop range (three stops over before detail burns out, andr four stops under before detail blocks up.) Guy Holt, Gaffer, ScreenLight & Grip, Lighting & Grip sales and rental in Boston because they have a greater exposure range

Phil, as always, you are correct. The "Deep Blue Sea" (1999) starred Saffron Burrows. I meant "The Deep Blue Sea" (2011) with Rachel Weisz. I failed to encapsulate "The" in the quotation marks. You are such a nitpicker. Guy

This is a complicated subject. The key tone is the common reference point used by light meters, lab processors, and transfer colorists. Simply put it is properly exposed 18% gray (sometimes called mid gray because it appears in the middle of a photographic gray scale.) It is the reference point to which we peg all other values on the characteristic curve of the film. Take meters for example: there are basically two types of meters: incident and spot. Incident meters read the light falling on your subject. Spot meters read the light reflecting back from your subject. An incident reading gives you an exposure that after normal processing would render an 18% gray card as 18% gray (a specific density of the film) had you held it in front of the camera in the same light. Incident meters enable you to peg the key tone (18% gray) in this fashion even though there may not be a mid-tone in your scene. A spot meter is then typically used to take reflective readings to see how other objects will expose relative to the key tone that was pegged with the incident meter. The thing to remember about spot meters is that they want to expose everything as mid gray. For instance, if you expose a black piece of paper with the reading of a spot meter it will appear as mid gray after normal processing (not pushed or pulled) – likewise for a white piece of paper. But, if you place an incident meter down on the black piece of paper and expose for the incident reading the black paper will be black, and the white paper will be white, after normal processing because you exposed for the key tone by using the incident reading and thereby pegged the other values (white and black) relative to it. You use the reading from the spot meter to be sure that the object you are metering will be within the exposure range (characteristic curve) of the film stock you are using. If the stock has a nine stop range (five stops over before detail burns out, and four stops under before detail blocks up), and your reading of a dark object is six stops under your key tone, it will not be rendered on the film after it is processed normal (to reproduce mid gray as mid gray). Since in this situation the contrast range of the scene is beyond the exposure range of the film you have two choices. 1) You can open up and expose for the shadows (over exposing the key tone and blowing out your highlights more in the process) and print down to make mid gray mid gray again. In the end you have the detail in the shadows you want, but in the process you have lost detail in the highlights. Why? Because the contrast range of the scene was beyond the exposure range of the film, and you exposed for shadow detail, you burned out the highlights (no detail) so it is not there when you print down to mid gray. You can't bring it back. Is that bad - not necessarily. It's just another "look." Or, 2) you can throw some light into the shadows to bring the reflective value of the dark object within the exposure range of the film (onto the straight portion of its’ characteristic curve) without changing the exposure of the key tone value (mid gray) or blowing out the highlights. In this fashion you fit the contrast range of your scene into the exposure range of the film emulsion you are using (the scene from "Miller's Crossing" discussed above being an example.) Of course this is only the starting point. From this “correct” exposure a DP will further manipulate the relationship of the contrast range of a scene to the exposure range of the film stock to create a desired effect (see Bob Richardson’s work in Django.) This is old school film exposure theory, but it is a good conceptual frame work for exposing digital video, especially now that you can record "raw" and apply "looks" to the raw data. If you don’t have an incident meter, but want to peg the key tone under your subject's key light, an old trick is to take a spot meter reading of the palm of your hand under the key light and open up one full stop. This will give you a close approximation because the average Caucasian flesh tone is one stop more reflective than 18% gray. I hope this helps. Guy Holt, Gaffer, ScreenLight & Grip, Lighting & Grip Sales and Rentals in Boston

I'm not exactly sure what you mean by "sophisticated" lighting. But, if I had to guess it would probably be this scene from “Miller’s Crossing” ( I have posted it on my server at http://www.screenlig...ing_Example.jpg.) Here is a description of what makes this scene sophisticated that I posted elsewhere in this forum: It is a common fallacy that dark scene’s like this are “underexposed.” This scene is not underexposed, but rather the reflective values of the objects in the scene are carefully balanced (placed on the film’s characteristic curve) relative to the key tone by lighting so that most of the scene remains dark but serves up the full contrast range the film emulsion is capable of. In other words, even though the scene is correctly exposed, nothing in the scene is “correctly” exposed. The flesh tones are underexposed and the lampshade is over exposed in order to create the mood of the scene. In an instance like this, the DP would not use a meter (incident or spot) to find the exposure of the key tone; rather, he would choose the exposure of the key tone from the outset - say T5.6 for deep focus. And, having balanced the elements of the scene to that exposure using either his incident or spot meter, he will “lock it in” for lab timers or transfer colorists, by giving them the key tone (by properly exposing a chip chart with an 18% gray patch) as a reference at the head of the scene. Without providing the key tone, a timer or colorist will not know how dark the shadows should be or how bright the highlights should be because there is no other reference value at full exposure by which to calibrate the brightness of the scene. Here are a few techniques, all of which are evident in this shot, that one could use to balance the lighting to create a dark scene without under exposing it. 1) Edge light objects in frame. Use reverse keys for talent and underexpose flesh tones by at least two stops or more. As long as you define the contours of your subject with subtle underexposed edges, don’t be afraid to let your talent fall off into black. There is a scene beautifully lit by James Merifield in the “Deep Blue Sea” of Rachel Wiesz and Harry Hadden-Paton standing in a dark alley way. They are back light by a practical at the end of the alley. Their contours are defined by the rims motivated by the practical, but otherwise their flesh tones fall off to complete shadows. James Merifield probably used a spot meter and negative fill to make sure that their flesh-tone would fall off the emulsion’s characteristic curve and reproduce as a pure silhouette. Sonnenfeld probably did the same in this scene to assure large parts of the frame had minimal detail. 2) I personally believe you should always have a hot spot in a frame – a practical in the scene or something in the deep background. You can shift your overall exposure in the camera or in post to create a dark scene, but without a hot spot reference in the frame it will lack contrast and look underexposed. A hot spot in the frame serves as a reference point and creates contrast. Practicals should be close to clipping and appear to be the source of light in a scene. 3) Don’t try to light your talent with only practical’s because they will blow out – the hot spot in your scene has to look natural. Not only is supplemental lighting required to light your talent, but you must also treat the practicals to make them look realistic. I find that practical lamps never look convincing unless one treats the lampshade as well as boost the bulb wattage. That is because if you stop down to keep the shade from burning out, the output of the practical, on the table it sits on or the wall its on, looks rather anemic. I find you get a more realistic look if you boost the wattage of the bulb and line the inside of the shade with ND gel. It is a delicate balance to obtain. You can obtain this delicate balance without a monitor, by using the old school method with incident and spot meters and a selection of practical bulbs including PH 211, 212, and 213 bulbs. Years ago Walter Lassaley, BSC, instructed me to balance practical’s such that an incident reading of the direct output one foot away from the bulb is one stop over exposure. I have found that rule of thumb gives a realistic output to the practical - the light emitted downward onto the table top and upward onto the wall or ceiling is realistic. After establishing the practical’s output using an incident meter, you then use a spot meter to determine how dense an ND gel is needed to line the inside of the shade to place the brightness value of the shade on the characteristic curve of the emulsion so that it does not too hot and without detail. 4) Define the edges of your frame with a little detail. As long as you define the edges of your frame with a little detail, as Sonnenfeld does here, you can leave most of it black without it looking under exposed. 5) Soft sources like China Balls and Kinos are the wrong kind of fixtures for this kind of scene. You will need fixtures that you can easily control because you will need to cut them off large parts of your set. It will be hard to keep china balls and Kino Flos from spilling light all over the place and filling shadow areas that you want to keep dark. Fresnels with light diffusion inside the doors, cut with flags and nets, will give you the control you need. Spot meter readings of objects on the edge of the frame, like the upholstered chair on the left, will tell you if they are within the exposure range (characteristic curve) of the film. If they are not, use a little light to bring out detail that will define the edges of the frame as Sonnenfield has done here with the chair. Guy Holt, Gaffer, ScreenLight & Grip, Lighting and Grip Equipment Sales and Rentals in Boston.

I agree with Adrian. Don’t try to light your talent with only practical’s because they will blow out – the hot spot in your scene has to look natural. Not only is supplemental lighting required to light your talent, but you must also treat the practicals to make them look realistic. I find that practical lamps never look convincing unless one treats the lampshade as well as boost the bulb wattage. That is because if you stop down to keep the shade from burning out, the output of the practical, on the table it sits on or the wall its on, looks rather anemic. I find you get a more realistic look if you boost the wattage of the bulb and line the inside of the shade with ND gel. It is a delicate balance to obtain. You can obtain this delicate balance without a monitor, by using the old school method with incident and spot meters and a selection of practical bulbs including PH 211, 212, and 213 bulbs. Years ago Walter Lassaley, BSC, instructed me to balance practical’s such that an incident reading of the direct output one foot away from the bulb is one stop over exposure. I have found that rule of thumb gives a realistic output to the practical - the light emitted downward onto the table top and upward onto the wall or ceiling is realistic. After establishing the practical’s output using an incident meter, you then use a spot meter to determine how dense an ND gel is needed to line the inside of the shade so that the shade does not become too hot. Guy Holt, Gaffer, New England Studios, Lighting and Grip Rental & Sales in Boston

The poor Power Factor of HMIs have been vexing set electricians for years. For more information about the adverse effects these loads can have on generators and power distribution systems, and how to remedy them so that you can operate bigger, or more small, lights on portable generators or house power than has ever been possible before, join me in a workshop I am teaching on Feb. 16th titled “Lighten Up: Doing More with Less without Compromise.” As part of the same workshop series, New England Studios, Talamas Broadcast, and Production Hub will be sponsoring a workshop on “Video Lighting Design” by L.D. Richard Cadena on Feb. 9th. Noted Focal Press Author, ETCP Trainer, and Founder of the Academy of Production Technology, Richard’s workshops are both lively and informative. Log onto bit.ly/nptwkshps for more workshop information and registration details. Guy Holt, Gaffer, New England Studios, Lighting & Grip Rental in Massachusetts

Unless you know what you are doing, hooking a 2000W Inverter up to a car battery is a recipe for disaster. First inverters require deep cycle batteries that are designed for continuous low amperage loads. Car batteries are designed to provide high amperage for short periods of time to crank engines. A 2000W inverter will drain a car battery in no time. Also 2000W at 12 V will draw 166 Amps. If you connect it with anything less than two ought feeder cable you will start a fire. You don't want to play around with 2000W Inverters unless you know what you are doing. One solution to Megan's dilemma is to use a portable generator like the new 10’000W Honda EB10000 with a boost transformer. 10’000W is just enough to power a good size HMI (say a 6k) to light the deep background and have enough power left over to power not only talent keys but also backlights, rim lights, and kickers to edge light your talent. A lot of productions hesitate to use non-blimped industrial generators like the new 10kw Honda EB100000 because of the noise they make. Whether you pick up generator noise on your audio tracks comes down to how you use it. A common problem with open-frame industrial generators like the EB10000 is that by the time you move them far enough off set that you don't hear them you have significant "Line Loss" (often referred to as "Voltage Drop") from the long cable run back to set. To the problem of line loss, you have the added problem that as you add load, the voltage drops on portable generators (it is not uncommon for a generator to drop 5-10 volts under full load.) The combination of voltage drop on the generator and line loss on a long cable run can cause voltage to drop to the point where HMI and Kino ballasts cut out unexpectedly or won't strike at all. Low voltage can also cause problems such as reduced efficiency and excessive heat in equipment, unnecessary additional load on the generator, and a dramatic shift in the color temperature and in the output of lights. For these reasons, portable gas generators are typically operated too close to set where they are picked up on audio tracks. The trick to recording clean audio with the EB10000 is to use the generator with a boost transformer that will enable you to operate the generator at a distance where it won’t be heard, yet maintain full line level on set. Honda EB10000 with Voltage Select 84A Transformer/Distro and 14 Gallon Fuel Caddy A boost transformer will enable you to add 300'- 400' of larger gauge 250V twist-lock extension cable between the generator and the transformer serving as a Distro box. This is usually enough cable to place the generator around the corner of a building, or to run it out of a van or truck - which is usually all the additional blimping you need with these generators. The heavy-duty 250V twist-lock cable eliminates multiple long cable runs to the generator and minimizes line-loss (eliminating the severe voltage drop you would have using standardelectrical cords.) And, by compensating for the unavoidable voltage drop you will have on a fully loaded generator, a boost transformer will assure full line level (120V) on set. Left: Honda EB10000 operating out of grip truck (note set at distance (bright spot on right side.)) Center: 84A Full Power Transformer/Distro compensates for Voltage Drop over 400ft cable run. Right: Beach Set with 120v full line level 500ft from power source. A good example of how the voltage boost capacity of boost transformer makes it possible to record clean audio tracks with the EB10000, even under the worst of conditions, is the indie short "Paralarva" (pictured above and below.) The film takes place around a campfire on a beach on Cape Cod. To record sync sound without picking up the noise of a generator, the crew ran our modified 10kw Honda EB10000 out of their grip truck 500 ft from their beach set. To assure full line level on set, the production used the boost capacity of our 84A Select Transformer/Distro to compensate for the line loss over the long cable run. Left: Beach Set lit by two 1800W Arrimaxes. Center: Secondary side power distributed with standard 100 Bates Gang Boxes. Right: Set viewed from generator (note: distance and extent of set power distribution.) From the Transformer/Distro they then ran 100' of 4/3 Bates Extension to set where they broke out to 20A Edison receptacles using 100A gang boxes. While running the generator near full capacity with a lighting package that consisted of two 1800W Arri M18 Baby Max HMIs, several Tegra 400s, and assorted Litepanels and Quartz Fresnels, they experienced no appreciable voltage drop on set even after a 500' cable run because our Select Transformer/Distro was able to compensate for both the line loss of the cable and voltage drop of the generator under near full load. Left: Ready for rain on the set of "Gasp." Center: Two 4kw Pars operate on a 10kw Honda EB10000 Generator through our 84A Full Power Transformer/Distro. Right: 100A Shock Block GFCI downstream of Full Power Transformer/Distro offers Ground Fault Protection for entire 100A distro system By comparison, had the crew of "Paralarva" run 500' of standard 14 Awg electrical cord they would have experienced a line loss alone of 24.5V. To avoid having their 1800W Baby Maxs cut out from low voltage, they would have had to move the generator closer to set where it would be picked up on the audio tracks. This example clearly demonstrates how the boost capacity of transformers can enable you to not only place the generator further from set where it won't be heard, but also assure that the supply voltage on set does not drop too low (use this link for information about Line-Loss and how to combat it.) Line loss compensation is just one of the many benefits to be gained by using a boost transformer on the new Honda EB10000 generator (use this link for details.) Guy Holt, Gaffer, New England Studios, Lighting and Grip Eq. Rental & Sales in Boston

The problem with a lot of indie night exteriors (Paul’s Educational Video being a good example) is that they generally don’t have the power to edge light their talent or light the deep background. As a result, their faces look disembodied like they are floating in a black void. The high cost of blimped studio generators is one of the biggest hurdles to lighting night exteriors. Not only are blimped generators expensive to rent, but they also come with hidden costs. Since rental trucks like those from Ryder or Penske are not equipped to tow, you have to hire the rental house’s grip truck to tow them. And, since most rental houses require that one of their employees drive their trucks for insurance reasons, the production has to hire a driver at roughly $575/10hrs – which is probably more than anyone else on a typical indie crew is getting paid. One solution to this dilemma is to use a portable generator like the new 10’000W Honda EB10000 with a boost transformer. 10’000W is just enough to power a good size HMI (say a 6k) to light the deep background and have enough power left over to power not only talent keys but also backlights, rim lights, and kickers to edge light your talent. A lot of productions hesitate to use non-blimped industrial generators like the new 10kw Honda EB100000 because of the noise they make. Whether you pick up generator noise on your audio tracks comes down to how you use it. A common problem with open-frame industrial generators like the EB10000 is that by the time you move them far enough off set that you don't hear them you have significant "Line Loss" (often referred to as "Voltage Drop") from the long cable run back to set. To the problem of line loss, you have the added problem that as you add load, the voltage drops on portable generators (it is not uncommon for a generator to drop 5-10 volts under full load.) The combination of voltage drop on the generator and line loss on a long cable run can cause voltage to drop to the point where HMI and Kino ballasts cut out unexpectedly or won't strike at all. Low voltage can also cause problems such as reduced efficiency and excessive heat in equipment, unnecessary additional load on the generator, and a dramatic shift in the color temperature and in the output of lights. For these reasons, portable gas generators are typically operated too close to set where they are picked up on audio tracks. The trick to recording clean audio with the EB10000 is to use the generator with a boost transformer that will enable you to operate the generator at a distance where it won’t be heard, yet maintain full line level on set. Honda EB10000 with Voltage Select 84A Transformer/Distro and 14 Gallon Fuel Caddy A boost transformer will enable you to add 300'- 400' of larger gauge 250V twist-lock extension cable between the generator and the transformer serving as a Distro box. This is usually enough cable to place the generator around the corner of a building, or to run it out of a van or truck - which is usually all the additional blimping you need with these generators. The heavy-duty 250V twist-lock cable eliminates multiple long cable runs to the generator and minimizes line-loss (eliminating the severe voltage drop you would have using standardelectrical cords.) And, by compensating for the unavoidable voltage drop you will have on a fully loaded generator, a boost transformer will assure full line level (120V) on set. Left: Honda EB10000 operating out of grip truck (note set at distance (bright spot on right side.)) Center: 84A Full Power Transformer/Distro compensates for Voltage Drop over 400ft cable run. Right: Beach Set with 120v full line level 500ft from power source. A good example of how the voltage boost capacity of boost transformer makes it possible to record clean audio tracks with the EB10000, even under the worst of conditions, is the indie short "Paralarva" (pictured above and below.) The film takes place around a campfire on a beach on Cape Cod. To record sync sound without picking up the noise of a generator, the crew ran our modified 10kw Honda EB10000 out of their grip truck 500 ft from their beach set. To assure full line level on set, the production used the boost capacity of our 84A Select Transformer/Distro to compensate for the line loss over the long cable run. Left: Beach Set lit by two 1800W Arrimaxes. Center: Secondary side power distributed with standard 100 Bates Gang Boxes. Right: Set viewed from generator (note: distance and extent of set power distribution.) From the Transformer/Distro they then ran 100' of 4/3 Bates Extension to set where they broke out to 20A Edison receptacles using 100A gang boxes. While running the generator near full capacity with a lighting package that consisted of two 1800W Arri M18 Baby Max HMIs, several Tegra 400s, and assorted Litepanels and Quartz Fresnels, they experienced no appreciable voltage drop on set even after a 500' cable run because our Select Transformer/Distro was able to compensate for both the line loss of the cable and voltage drop of the generator under near full load. Left: Ready for rain on the set of "Gasp." Center: Two 4kw Pars operate on a 10kw Honda EB10000 Generator through our 84A Full Power Transformer/Distro. Right: 100A Shock Block GFCI downstream of Full Power Transformer/Distro offers Ground Fault Protection for entire 100A distro system By comparison, had the crew of "Paralarva" run 500' of standard 14 Awg electrical cord they would have experienced a line loss alone of 24.5V. To avoid having their 1800W Baby Maxs cut out from low voltage, they would have had to move the generator closer to set where it would be picked up on the audio tracks. This example clearly demonstrates how the boost capacity of transformers can enable you to not only place the generator further from set where it won't be heard, but also assure that the supply voltage on set does not drop too low (use this link for information about Line-Loss and how to combat it.) Line loss compensation is just one of the many benefits to be gained by using a boost transformer on the new Honda EB10000 generator (use this link for details.) Guy Holt, Gaffer, New England Studios, Lighting and Grip Eq. Rental & Sales in Boston

Alan’s following statement is also technically inaccurate: Technically speaking the 4k and 2.5k designation of the HMIs above is not their power consumption, but their light output. Unlike incandescent lights, HMIs consume more power than they generate in light. The relationship between what they generate (their True Power) to what they consume (their Apparent Power) is their Power Factor. Here is a simple explanation of Power Factor in HMI & Kino ballasts. With a purely resistive AC load (Incandescent Lamps, Heaters, etc.) voltage and current waveforms are in step (or in phase), changing polarity at the same instant in each cycle (a high power factor or unity.) With “non-linear loads” (magnetic and electronic HMI ballasts) energy storage in the loads, increases the amount of current drawn and results in a time difference between the current and voltage waveforms – they are out of phase (a low power factor.) In other words, during each cycle of the AC voltage, extra energy, in addition to any energy consumed in the load, is temporarily stored in the load in electric or magnetic fields, and then returned to the power distribution a fraction of a second later in the cycle. The "ebb and flow" of this nonproductive power increases the current in the line. Thus, a load with a low Power Factor will use higher currents to transfer a given quantity of real power than a load with a high Power Factor. In short, HMIs draw more current to generate the same wattage of light as an incandescent fixture. The poor Power Factor of HMIs, Kinos, CLF lamp banks, and even LEDs, have been vexing set electricians for years. For more information about the adverse effects these loads can have on generators and power distribution systems, and how to remedy them so that you can operate bigger, or more small, lights on portable generators or house power than has ever been possible before, join me in a workshop I am teaching on Feb. 16th titled “Lighten Up: Doing More with Less without Compromise.” As part of the same workshop series, New England Studios, Talamas Broadcast, and Production Hubwill be sponsoring a workshop on “Video Lighting Design” by L.D. Richard Cadena on Feb. 9th. Noted Focal Press Author, ETCP Trainer, and Founder of the Academy of Production Technology, Richard’s workshops are both lively and informative. Log onto bit.ly/nptwkshps for more workshop information and registration details. Guy Holt, Gaffer, New England Studios, Lighting & Grip Rental in Massachusetts

I have posted on my server at http://www.screenlig...ing_Example.jpg an example from “Miller’s Crossing” that might help make sense of my post above. It is a common fallacy that dark scene’s like this are “underexposed.” This scene is not underexposed, but rather the reflective values of the objects in the scene are carefully balanced (placed on the film’s characteristic curve) relative to the key tone by lighting so that most of the scene remains dark but serves up the full contrast range the film emulsion is capable of. In other words, even though the scene is correctly exposed, nothing in the scene is “correctly” exposed. The flesh tones are underexposed and the lampshade is over exposed in order to create the mood of the scene. In an instance like this, the DP would not use a meter (incident or spot) to find the exposure of the key tone; rather, he would choose the exposure of the key tone from the outset - say T5.6 for deep focus. And, having balanced the elements of the scene to that exposure using either his incident or spot meter, he will “lock it in” for lab timers or transfer colorists, by giving them the key tone (by properly exposing a chip chart with an 18% gray patch) as a reference at the head of the scene. Without providing the key tone, a timer or colorist will not know how dark the shadows should be or how bright the highlights should be because there is no other reference value at full exposure by which to calibrate the brightness of the scene. Here are a few techniques, all of which are evident in this shot, that one could use to balance the lighting to create a dark scene without under exposing it. 1) Edge light objects in frame. Use reverse keys for talent and underexpose flesh tones by at least two stops or more. As long as you define the contours of your subject with subtle underexposed edges, don’t be afraid to let your talent fall off into black. There is a scene beautifully lit by James Merifield in the “Deep Blue Sea” of Rachel Wiesz and Harry Hadden-Paton standing in a dark alley way. They are back light by a practical at the end of the alley. Their contours are defined by the rims motivated by the practical, but otherwise their flesh tones fall off to complete shadows. James Merifield probably used a spot meter and negative fill to make sure that their flesh-tone would fall off the emulsion’s characteristic curve and reproduce as a pure silhouette. Sonnenfeld probably did the same in this scene to assure large parts of the frame had minimal detail. 2) I personally believe you should always have a hot spot in a frame – a practical in the scene or something in the deep background. You can shift your overall exposure in the camera or in post to create a dark scene, but without a hot spot reference in the frame it will lack contrast and look underexposed. A hot spot in the frame serves as a reference point and creates contrast. Practicals should be close to clipping and appear to be the source of light in a scene. 3) Don’t try to light your talent with only practical’s because they will blow out – the hot spot in your scene has to look natural. Not only is supplemental lighting required to light your talent, but you must also treat the practicals to make them look realistic. I find that practical lamps never look convincing unless one treats the lampshade as well as boost the bulb wattage. That is because if you stop down to keep the shade from burning out, the output of the practical, on the table it sits on or the wall its on, looks rather anemic. I find you get a more realistic look if you boost the wattage of the bulb and line the inside of the shade with ND gel. It is a delicate balance to obtain. You can obtain this delicate balance without a monitor, by using the old school method with incident and spot meters and a selection of practical bulbs including PH 211, 212, and 213 bulbs. Years ago Walter Lassaley, BSC, instructed me to balance practical’s such that an incident reading of the direct output one foot away from the bulb is one stop over exposure. I have found that rule of thumb gives a realistic output to the practical - the light emitted downward onto the table top and upward onto the wall or ceiling is realistic. After establishing the practical’s output using an incident meter, you then use a spot meter to determine how dense an ND gel is needed to line the inside of the shade to place the brightness value of the shade on the characteristic curve of the emulsion so that it does not too hot and without detail. 4) Define the edges of your frame with a little detail. As long as you define the edges of your frame with a little detail, as Sonnenfeld does here, you can leave most of it black without it looking under exposed. 5) Soft sources like China Balls and Kinos are the wrong kind of fixtures for this kind of scene. You will need fixtures that you can easily control because you will need to cut them off large parts of your set. It will be hard to keep china balls and Kino Flos from spilling light all over the place and filling shadow areas that you want to keep dark. Fresnels with light diffusion inside the doors, cut with flags and nets, will give you the control you need. Spot meter readings of objects on the edge of the frame, like the upholstered chair on the left, will tell you if they are within the exposure range (characteristic curve) of the film. If they are not, use a little light to bring out detail that will define the edges of the frame as Sonnenfield has done here with the chair. Guy Holt, Gaffer, ScreenLight & Grip, Lighting and Grip Equipment Sales and Rentals in Boston.

This is a complicated subject and every DP has their own approach. Basically there are two types of meters: incident and spot. Incident meters read the light falling on your subject. Spot meters read the light reflecting back from your subject. An incident reading gives you an exposure that would expose an 18% gray card as 18% gray if you held it in front of the camera in the same light. Incident meters enable you to peg the key tone (18% gray) in this fashion. A spot meter is then typically used to take reflective readings to see how other objects will expose relative to the key tone that was pegged with the incident meter. The thing to remember about spot meters is that they want to expose everything as mid gray. For instance, if you expose a black piece of paper with the reading of a spot meter it will appear as mid gray after processing – likewise for a white piece of paper. But, if you place an incident meter down on the black piece of paper and expose for the incident reading the black paper will be black, and the white paper will be white, after processing because you pegged the key tone and exposed for mid gray by using the incident reading. You use the reading from the spot meter to be sure that the object you are metering will be within the exposure range (characteristic curve) of the film stock you are using. If the stock has a nine stop range (four stops over before detail burns out, andr three stops under before detail blocks up), and your reading of a dark object is four stops under your key tone, you have two choices. You can open up and expose for the shadows (blowing out your highlights more) or you can throw some light into the shadows to bring the reflective value of the dark object within the exposure range of the film (onto the straight portion of its’ characteristic curve) without changing the key tone value or blowing out the highlights. In this fashion you fit the contrast range of your scene into the exposure range of the film emulsion you are using. Of course this is only the starting point. From this “correct” exposure a DP will further manipulate the relationship of the contrast range of a scene to the exposure range of the film stock to create a desired effect (see Bob Richardson’s work in Django.) If you don’t have an incident meter, but want to peg the key tone under your subject's key light, an old trick is to take a spot meter reading of the palm of your hand under the key light and open up one full stop. This will give you a close approximation because the average Caucasian flesh tone is one stop more reflective than 18% gray. I hope this helps. Guy Holt, Gaffer, ScreenLight & Grip, Lighting & Grip Sales and Rentals in Boston

David is right, to successfully light a night scene on a tight budget requires that you first have a concept for the shot. From there you can figure out an innovative approach to accomplish that look. What tools who need and how you deploy them will follow. A good example is a very similar scene I lit on a “low budget” feature called "Black Irish." It was a pivotal scene where the youngest son of an Irish American patriarch crashes his derelict older brother's car setting off an unfortunate series of events. For the scene we had to light 1000 ft of Marginal Street in Chelsea for driving shots on a process trailer and the scene of the accident. Our biggest challenge was to create through the lighting the feel of a car hurdling down the road at high speed. The problem was that even after lighting the equivalent of three football fields, the process trailer couldn't obtain a speed of more than 30 mph before it was out of the light. The traditional approach of under-cranking the camera to increase the speed was not an option because the scene was a pivotal one with extensive dialogue inside the car. So, we had to create the effect of speed through the lighting. I came up with a concept that was as beautiful in its practical simplicity as in its psychological complexity. To heighten the sense of speed of the process trailer shots we rigged 500w practical fixtures along a four hundred foot wall on one side of the road. We spaced the practical wall lights twice as close together as they would be normally. This way, as the car passed by, areas of light and dark would pass rapidly by in the background and exaggerate the speed at which the car was traveling. When it came time to shoot the static wide establishing shot of the car racing down the road, we dismantled every other wall practical in order to reinforce the effect. On an unconscious level the viewer's mind registers in the establishing shot the wider spacing of the wall lamps. So when in the close up process shots the pools of light in the background are racing past at twice the rate because there are, in fact, twice as many lights, the viewer's mind registers the car is traveling at twice the speed it is, in fact, traveling. In addition to the wall practicals, I simulated car dash board light on the actor's faces with a 12v 9" Kino Car kit. The play of the passing wall lights on the actor's faces were created by a revolving 650W Fresnel with diffusion on its doors rigged on the process trailer. To light the long stretch of road, I simulated the pools of light that would be created by street lights by rigging 6kw space lights under the baskets of 60' condors that were spaced about 200' apart over the road. In addition to the Space Light, each condor basket also carried a 4k HMI Par that filled the stretches of road between the pools of tungsten light with a cool moonlight. To continue the moonlight down the road there was yet another 4k HMI Par on a Mambo Combo Stand. Because this 4K was further down the road than was practical to run cable, it was powered by a Honda 5500W portable generator. A 12kw HMI Fresnel with 1/2 CTO through a 12x frame of Soft Frost served to pick up the deep background from the front on one end of Marginal Street while a 6kw HMI Par lit the other end. To supply power on both sides of the road for a 1000' stretch was no small task. I used three generator plants strategically placed so that our cable would never cross the road in a shot. In addition to the Honda 5500W portable generator that powered the 4kw HMI Par light for the deep background, I used a 800A plant to power the 4kw HMI Pars and 6kw Space Lights in the condors, the 12kw Fresnel, and the base camp trailers and work lights. The 6kw Par, 12 - 500W practicals, and an assortment of smaller HMI's used to light the post crash scene were powered by a 450A plant on the far end of the roadway. This example, demonstrates that once you have a concept you can come up with an innovative approach to accomplish it. The tools and how to deploy follow. This example also demonstrates that the right tools, used in an innovative way, can create startling results on a low budget. Since “low budget” is a relative term, to address Megan’s situation, it would be helpful to know what the budget is for this scene and have more details about the sequence and location. Guy Holt, Gaffer, ScreenLight & Grip, Lighting Rental & Sales in Boston

The KVA above is for a 1200W HMI operating on an non-PFC electronic ballast. The KVA for a 575 operating on the same type of ballast would be roughly half that. The KVA would be different for an electronic ballast with Power Factor Correction or a magnetic ballast. Take a 1200W magnetic HMI ballast for example.In magnetic HMI ballasts, through a phenomenon called Inductive Reactance, the multiple fine windings of the ballast transformer induces considerable current, called Reactive Power, that is in opposition to the primary current, causing the primary current to lag behind voltage, a reduction of current flow, and an inefficiency in the use of power. Put simply, the ballast draws more power than it uses to create light. If, in this situation, you were to measure the current (using a Amp Meter) and voltage (using a Volt Meter) traveling through the cable supplying the magnetic HMI ballast and multiply them according to Ohm’s Law (W=VA) you would get the “Apparent Power” of the ballast (expressed as KVA.) But, if you were to instead, use a wattmeter to measure the actual amount of energy being converted into real work (light) by the ballast, after the applied voltage overcomes the induced voltage, you would get the “True Power” of the ballast (expressed as KW.) The difference between Apparent Power and True Power, or the additional power required for the applied voltage to overcome the induced voltage, is the Reactive Power (expressed as KVAR.) The ratio of True Power to Apparent Power is called the “Power Factor” of the ballast. The favorite analogy electricians like to use to explain these terms is that if Apparent Power is a glass of beer, Reactive Power is the foam that prevents you from filling it up all the way, so that you are left with less beer or Ture Power. In other words, the thirst-quenching portion of your beer is represented by KW in the figure above. The foam is represented by KVAR. The total contents of your mug, KVA, is this summation of KW (the beer) and KVAR (the foam). In our beer mug analogy, Power Factor (P.F.) is then the ratio of Beer (True Power) to the entire volume of the mug (beer plus foam or Apparent Power.) Thus, for a given KVA: the more foam you have (the higher the percentage of KVAR), the lower your ratio of KW (beer) to KVA (beer plus foam). Thus, the lower your power factor. Or, the less foam you have (the lower the percentage of KVAR), the higher your ratio of KW (beer) to KVA (beer plus foam). In fact, as your foam (or KVAR) approaches zero, your power factor approaches 1.0. When lights with a low power factor are used, a generator must be sized to supply the apparent power (beer plus foam), even though only the beer (true power) counts as far as how much actual drinking is possible. Where a typical 1200W magnetic HMI ballast takes 13.5 Amps at 120 Volts to generate 1200 Watts of light the power factor is .74 (13.5A x 120V= 1620W, 1200W/1620W= .74). Our beer mug analogy is a bit simplistic. In reality, when we calculate KVA, we must determine the “vectorial summation” of KVAR and KW. Therefore, we must go one step further and look at the angle between these vectors. To understand this concept let’s use the analogy of a man dragging a heavy load as illustrated above. The man’s Working Power (or True Power) in the forward direction, where he most wants his load to travel, is KW. Unfortunately, the man can’t drag his load on a perfect horizontal (he would get a tremendous backache), so his shoulder height adds a little Reactive Power, or KVAR. The Apparent Power the man is dragging, KVA, is this “vectorial summation” of KVAR and KW. The “Power Triangle” below illustrates this relationship between KW, KVA, KVAR, and Power Factor: In an ideal world (one without gravity), the man wouldn’t have to waste any power along his body height and so the KVAR would be very small (approaching zero.) KW and KVA would be almost equal and so the angle (formed between KW and KVA) would approach zero and the Cosine would then approach one. Power Factor would then approach one. For a light to be considered “efficient”, the Power Factor should be as close to 1.0 as possible. Where a typical 1200W magnetic HMI ballast takes 13.5 Amps at 120 Volts ( KVA =13.5A x 120V= 1620W), to generate 1200 Watts of light (KW), the Power Factor is .74 (PF = KW/KVA=1200W/1620W= .74). In other words, our 1200W magnetic ballast wastes roughly 25% of the power that it uses in Inductive Reactance. Guy Holt, Gaffer, ScreenLight & Grip, Lighting Sales and Rentals in Boston

There are a number of possible factors contributing to the problems Greg had. Besides the Power Factor of the ballast, you also have to take into account line loss, resistance, and harmonics. Which of these accounts for the problems Greg had depends on what type of HMI ballast he was using – magnetic, Power Factor Corrected (PFC) electronic, or non-PFC electronic ballasts. It is probably safe to assume that Greg was using HMIs with non-PFC electronic ballasts. Electronic HMI ballasts without power factor correction draw current in large pulses and return harmonic currents to the power stream. The capacitive reactance of electronic HMI ballasts also causes current to lead voltage and so they also have a leading power factor. I won’t go into detail here on the adverse effects that the Leading Power Factor and harmonics generated by non-PFC electronic HMI ballasts can have, but anyone operating HMI, Kino, and even LEDs should make them selves acquainted with harmonics. (use this link for more details.) Considering just the higher amperage draw of HMI electronic ballasts without PFC, an electronic square wave HMI ballast typically has a power factor less than .6 meaning the ballast has to draw 40 percent or more power than it uses. How much current a ballast will draw is indicated on the manufacturer’s nameplate. Let’s take a look at one of these nameplates, since deciphering them can be as difficult as deciphering Egyptian Hieroglyphs if you don’t know how to read them. Manufacturer’s nameplate from an Arri 575/1200 Electronic Ballast specifying its’ electrical characteristics (learn how to read it.) Above is the nameplate from an Arri non-PFC 575/1200 Electronic Ballast. The first thing to look for is the ballast’s Volt-Amperes (VA), which is called “Pmax” here. Calculated as the RMS voltage times the current measured at the input to the device, Volt-Amperes is the measurement of "Apparent Power" delivered to a load, which is different than Wattage. Wattage is the True Power dissipation of the lamp calculated by integrating the product of current through the lamp and voltage over time. These may sound like they would be the same (they are in the case of incandescent lamps), however one characteristics of HMI, Flourescent, and LED power supplies is that some of the current flowing into them is discharged back into the power line, without actually doing work, which in the case of ballasts is the generation of light. The relationship between True and Apparent Power is called the Power Factor (PF.) Since, the Wattage will always be lower than or equal to the Volt-Amperes, PF varies from 0.0 to 1.0. As indicated on its’ nameplate, this ballast has an Apparent Power of 2290VA - which means it draws nearly twice the load of its’ 1200W output. Next to the Pmax, it also indicates that the Power Factor is .6 (cos@=.6), or that the greater Apparent Power drawn by the ballast consists not only of high amplitude short pulses of current, but also harmonic currents that the ballast returns into the distribution system. The next thing to look for is the relationship between Voltage (U) and Current (I). As this nameplate indicates this ballast will operate with line voltages ranging from 90 to 125 volts (US), and 180 to 250 volts (European.) You will also notice that the current (I) the ballast draws varies with the supply voltage. That is because this ballast is a “Constant Power” ballast. With constant power ballasts, if voltage drops the ballast will draw more current to maintain a constant Apparent Power - 2290VA in this case. For example, according to the nameplate it will draw 18A of current (I) at 125 Volts (U) (2290VA/125V = 18.32A.) If the voltage drops to 90V, it will draw over 25 Amps (2290VA/90V = 25.44A.) This is an important characteristic of this ballast that should be taken into account when used outside the studio on location. With an Apparent Power of 2290VA, this non-PFC constant power HMI ballast will operate very close to the threshold of a 20A circuit – too close to operate reliably unless precautions are taken. For example, according to its’ nameplate, it takes 19 Amps at 120 Volts to generate 1200 Watts of light (2290W/120V = 19A). If there is any line loss from a long cable run, the ballast will possibly draw over 20 Amps in order to compensate for the voltage drop. For instance, at 110V it will draw 20.8 Amps. To the problem of line loss, usually there is also increased resistance from an overheated plug end, which makes the voltage drop even further. Since most stinger plug-ends are only rated for 15 Amps they tend to overheat with 1200W non-PFC electronic ballasts. The increased resistance that results from the heat causes the voltage to the ballast to drop even further and so it will draw more power to maintain the 2290VA load. If the light is operating on a small generator, there will also be voltage drop on the generator because of the greater load. The voltage output of generators can drop 5-10 volts under load. At 105V, the ballst that drew 19A at 120V, will now draw 21.8 Amps and cause circuit breakers to overheat and potentially trip. If Greg was running standard electrical cord (14/3) with 15A Edison plug ends for a distance outside the windows, the load on the breaker could have been as high as 30Amps with the addition of the 575W HMI – which explains why it eventually overheated and tripped. For more facts/tips about power/HMIs/safety, check out an article I wrote for our company newsletter on the use of portable generators in motion picture production. Harry Box, author of “The Set Lighting Technician’s Handbook” has cited my article in the just released Fourth Edition of the handbook. In addition, he has established a link to it from the companion website for the Fourth Edition of the Handbook, called “Box Book Extras.” "Great work!... this is the kind of thing I think very few technician's ever get to see, and as a result many people have absolutely no idea why things stop working." "Following the prescriptions contained in this article enables the operation of bigger lights, or more smaller lights, on portable generators than has ever been possible before." The “Box Book Extras,” site is also worth checking out because it includes other source material used for the handbook, articles by Harry Box published in other periodicals, related websites, as well as more in depth discussion of topics touched upon in the handbook. You can log onto the Box Book Extras site FOR FREE at http://booksite.foca...x/setlighting/ with our pass-code "setlighting." Use this link for my FREE news letter article on the use of portable gas generators in motion picture production. Guy Holt, Gaffer, SceenLight & Grip, Lighting and Grip Rental & Sales in Boston

Yes, I would be interested in any production stills you have of the gennies in action. If you send them to me with a description of the production I will feature them on our website or our new Facebook page. Please send them to my attention at rentals@screenlightandgrip.com. Guy Holt, Gaffer, ScreenLight & Grip, Lighting Rental & Sales in Boston

Ditto. The great benefit, as I see it from this side of the Atlantic, is that you can operate up to 4kw HMIs off your wall receptacles. The biggest light we can plug directly into the wall is the new 1800W Arri M18; and, even then we are taking a chance of tripping a circuit breaker. The problem we have here with the Arri M18 is that many of our wall outlets are on 15 Amp circuits, and those that are on 20 Amp circuits probably use receptacles only rated for 15 Amps. This is a problem because the Arri 1800W ballast has an Apparent Power of 2250VA which means that it will draw 19.5 amps at 115V so it will always trip our ubiquitous 15A/120V house circuit and will trip a 20 Amp circuit if there is something else, like a computer or light, on the same circuit. Where you can't always know what else is on the same circuit, or even if it is a 20 or 15 Amp circuit, it is risky to plug the M18 into the wall. Especially since the house odds are stacked against you. With a draw of 19.5A at 115V, the load of the M18 is just too close to the threshold to operate reliably. Since the M18 uses a “Constant Power” ballast, if there is any line loss from a long cable run, or increased resistance from an overheated plug end, the draw of the ballast climbs over 20 Amps and trips the breaker. It has been my, and other Gaffer’s, experience with the M18 in this country that the stinger plug-ends overheat because they are only rated for 15 Amps. The increased resistance that results from the heat causes the voltage to the ballast to drop and so it has to draw more power to maintain the 1800W load. At 110V it will draw 20.5 Amps. The power drawn by the M18 is just too near the operating threshold of a 20A circuit for it to operate reliably plugged into our U-Ground Edison wall outlet. The same is true of Arri 1200W HMIs since most Arri 1200W HMI ballasts in this country are non-Power Factor Corrected and will draw 18.5A at 120V. The same is true of operating them on the 20A circuits of portable generators. Even though the generator’s Edison receptacles are rated for 20Amps, it has been my experience that you cannot run a M18 or non-PFC 1200 reliably on the 20A receptacles on the generator’s power panel. To the problem of line loss and overheating plug ends, you have the added problem with generators that as you add load the voltage drops on them. It is not uncommon for a generator to drop 10-15 volts under full load. The 1800W ballast that drew 19.5 Amps at 115 Volts off the wall will draw 21.4 Amps at 105 Volts off a generator. For these reasons, I am convinced that the 1800W power class was designed primarily for the EU market where its’ Apparent Power of 2250VA fits comfortably in your 13A/230V circuit. Here they work best on a real film distribution system where every circuit is 20 Amps, you know what is on the circuit because you are loading it yourself, and you are bringing the receptacle to the light because you are distributing the power yourself from a tie in or generator. When you can run a 100A whip and drop a Lunch Box next to the light you won’t have a problem. But, if your style of shooting requires that you run multiple stingers to plug into a wall or generator outlet, you will likely have problems with the plug ends or receptacle overheating and causing the breaker to overheat and trip. I have found that the only reliable way to power a M18 on wall out-lets or on portable gas generators in this country is from a 240V circuit through a 240v-to-120v step down transformer. A transformer will convert the 240V output into a single large 120V circuit that is more than capable of powering the 19.5A load of a M18. And, if the transformer is outfitted with a Bates receptacle, it will enable you to use a distro system that will allow you to move the generator off set (where it won’t be heard), compensate for line loss over a long cable run, and provide plug-in pockets conveniently close to the ballasts. Left: Honda EB10000 operating out of grip truck (note set atdistance (bright spot on right side.)) Center: 84A Full Power Transformer/Distro compensates for Voltage Drop over 350ft cable run. Right: Beach Set with 120v full line level 500ft from power source. To record sync sound without picking up the noise of even open frame portable generators like Honda’s new 10kw EB10000, all you need to do is add 300' of heavy gauge 250V twist-lock extension cable between the generator and the transformer. This is usually enough cable to place the generator around the corner of a building, or to run it out of a van or truck - which is usually all the additional blimping you need with the Honda generators. By using a single heavy-gauge feeder cable, you eliminate multiple long cable runs to the generator and the appreciable voltage drop you would have using standard electrical cords. Unlike 15 Amp U-Ground Edison plugs, a 250V Twist-Lock plug end won’t overheat and so won’t add resistance and won’t cause additional voltage drop that will cause the ballast to draw more power. Left: Beach Set lit by two 1800W Arrimaxes. Center: Secondary side power distributed with standard 100 Bates Gang Boxes. Right: Set viewed from generator (note: distance and extent of set power distribution.) Using a 240V-to-120V step-down transformer is generally the only way we can plug 4kw HMIs into wall receptacles and portable generators in this country also. Where as, you can plug them directly into your Honda Generators and your larger ring circuits with the Euro style 16A/230V receptacles. If I were lighting an indie film, I’d rather be in shoes than my own. Guy Holt, Gaffer, ScreenLight & Grip, Lighting Rentals and Sales in Boston

It gets a bit complicated with HMIs because it not only matters what type of HMI ballast you use, but also what type of generator you use. If the OP were using incandescent lights, he could use a home-depot type of AVR generator (AVR stands for Automatic Voltage Regulator.) However, the harmonic noise that the non-PFC electronic ballasts (both HMI & Kino) kick back into the power stream can have a severe adverse effect on the power waveform of conventional AVR generators like those available from Home Depot. The harmonic noise these light sources generate will not have nearly as bad an effect on the power supplied by an inverter generator like the Honda EU6500is. As the middle oscilloscope shot below indicates, when you power a standard non-PFC HMI Electronic ballast from a conventional portable generator, the harmonic noise they kick back into the power stream can have a severe adverse effect on the power waveform. Given the large sub-transient impedance of conventional portable generators, even a small degree of harmonic noise being fed back into the power stream will result in a large amount of distortion in its’ voltage. Left: Grid Power w/ 1.2Kw Arri non-PFC Elec. Ballast. Center: Conventional AVR Power w/ 1.2Kw Arri non-PFC Elec. Ballast. Right: Inverter Power w/ 1.2Kw Arri non-PFC Elec. Ballast. The adverse effects of the harmonic noise exhibited here, can take the form of overheating and failing equipment, circuit breaker trips, excessive current on the neutral wire, and instability of the generator’s voltage and frequency. Harmonic noise of this magnitude can also damage HD digital cinema production equipment, create ground loops, and possibly create radio frequency (RF) interference. When your lighting package consists predominantly of non-linear light sources, like HMI, Fluorescent, & LED lights, it is essential to have Power Factor Correction circuitry (PFC) in the ballasts and to operate them on an inverter generator. The combination of improved power factor and the nearly pure power waveform (1-2 %THD) of the inverter generator creates clean stable set power (like that in the power waveform below right). Left: Grid Power w/ 1.2Kw P-2-L PFC Elec. Ballast. Center: Conventional AVR Power w/ 1.2Kw P-2-L PFC Elec. Ballast. Right: Inverter Power w/ 1.2Kw P-2-L PFC Elec. Ballast. Corydon’s best bet would be to use a 575 with PFC ballast and use an inverter generator like the Honda EU2000is. The Honda EU2000is will also generate less than half the noise of Home Depot type generators – making it easier to record clean audio tracks. Guy Holt, Gaffer, ScreenLight & Grip, Lightng & Grip Rental and Sales in Boston

I recommend the just released 4th Edition of Harry Box’s “Set Lighting Technician’s Handbook.” Not a cheap book, but Harry Box has put together a free companion website called "Box Book Extras." The website includes the source material used for the handbook, articles by Harry Box published in other periodicals, related websites, a list of production oriented i-phone apps, as well as more in depth discussion of topics touched upon in the handbook.You can log onto the site at http://booksite.focalpress.com/box/setlighting/ with the pass-code "setlighting." - Guy Holt, Gaffer, ScreenLight & Grip, Lighting and Grip Rental in Boston

This is a complicated question, and given the amount of mis-information in this thread, it is hard to know where to begin. What makes it so complicated is that when it comes to running HMIs, Fluorescents, and LEDs on small portable generators, it matters not only what type of generator you use but also what type of power supply (ballast) the light uses. These issues have been vexing set electricians for years. Use this link for an informative newsletter article I wrote that explains the electrical engineering principles behind these issues and how to resolve them. This article is cited in the just released 4th Edition of Harry Box's "Set Lighting Technician's Handbook" and featured on the companion website "Box Book Extras." Of the article Harry Box exclaims: "Great work!... this is the kind of thing I think very few technician's ever get to see, and as a result many people have absolutely no idea why things stop working." "Following the prescriptions contained in this article enables the operation of bigger lights, or more smaller lights, on portable generators than has ever been possible before." The article is available online at http://www.screenlightandgrip.com/html/emailnewsletter_generators.html. Guy Holt, Gaffer, ScreenLight & Grip, Lightng & Grip Rental in Boston

The fundamental difference is that since there is no color to separate objects, one had to do so through the lighting. Remember two objects of very different color will reproduce as the same gray on B&W Film. For that reason you had to use "Reverse Keys", "Liners", and "Kickers' to separate objects from one another and talent from the background. It was easier to do so in those days because the productions were stage bound because of the large lamps required for the slow film. When faster color film stocks became available, and production moved onto real locations, this style of lighting was pretty much abandoned because it was more difficult to do without a studio grid and it was unnecessary because now an object's color would create separation. As a consequence, our images have become flatter. It took a child's innocence to make me realize this. At the screening of an American Experience program, "Murder at Harvard", that I lit the Old School way because it was filmed in B&W, my 8 year old daughter said it looked three dimensional when asked what she thought of the first B&W movie she had seen. Guy Holt, Gaffer, ScreenLight & Grip, Lighting equipment rental and sales in Boston

Look into the 8k Paparazzi Flash manufactured by Luminys Systems Corp (manufacturers of Softsun and Lightning Strikes lumnaries.} They are designed to simulate the barrage effect of paparazzi photographers, or for close-up tight shots where a controlled high-intensity flash is required. Single, quad, and eight-unit controllers are available. Light output is 8,000w Color temperature is 5600 Kelvin. Electrical power Connection is via 60Amp bates. The manufacturer's website is http://www.luminyscorp.com/products/lightning-strikes/parabolic.html. On the East Coast they are available from Available Light in NYC (http://www.alny.net/products.php?g=3&id=2.) Guy Holt, Gaffer, Owner/Operator of ScreenLight & Grip. Lighting and Grip equipment sales and rental in Boston

I don’t know if I would go this far since most HMI repairs don’t require servicing of electronics. I have operated a lighting rental house in Boston for over twenty years and, in all that time, there were only two problems that I could not fix myself and both had to do with blown IGBTs on 18ks. Most problems with HMIs have to do with the Head Cable, the Power Supply, or the Safety Loop. If you understand how HMIs work, you can usually identify the cause of the problem to be related to one of these three and repair it easily without having to get into component level repairs. To repair anything you must understand how it works, so you need to start by learning as much as you can about how HMIs operate in principle. Harry Box, author of the authoritative trade handbook “The Set Lighting Technician’s Handbook” has established a companion website to the Fourth Edition of the Handbook, called “Box Book Extras.” On it he has posted a very good article on trouble shooting HMIs (you can access the site with the password “set lighting.”) Our company news letter article on “Portable Generators in Motion Picture Production” also has a lot of useful information on HMIs. The article is available on-line at www.screenlightandgrip.com/html/emailnewsletter_generators.html. To make shop bench repairs easier, many manufacturers are now designing their equipment with easily swappable parts. For instance, a lot of the ARRI head electronics (igniter, spark gap, etc.) are a factory sealed block that you can only swap out; Power Gems is now designing their ballasts with swappable Power Modules; and Power-2-Light has designed their ballasts with diagnostic LEDS that will identify the board that has the problem so that you can simply swap the board. - Guy Holt, Gaffer, ScreenLight & Grip, Lighting & Grip rental in Boston MA

If all you have for power is a Honda 6500 you won’t be able to use a Xenon because both the Britelight (http://www.arclightefx.com/bl2k.htm) and Silverbeam PL-20 (http://www.phoebus.com/pdf/PSL-20.pdf) require 3 phase power – Honda 6500s are single phase generators. Your best bet is an HMI. What size HMI depends on what else you have to run on the generator. What else do you have to run on the genny? Guy Holt, Gaffer, ScreenLight & Grip

You will lose some flexibility with the generator permanently mounted in the van. You would do better to operate your Generac out of the van when possible - it will be no noisier. Guy Holt, Gaffer, ScreenLight & Grip. Lighting Sales & Rental in Boston.