Andy Jarosz

Hey Dan, Roe Black Pearl 2 panels are the standard for production.

The rod to lens center height is standardized, but there are sometimes exceptions. It's always best to double check.

On 6/16/2020 at 4:41 PM, Albion Hockney said:

Rosco Opti Scult seems to be focused on the theatrical world and more like just normal diffusion. (Video Below). I do wonder about a large array LED with narrow lenses built onto each diode or something. Would be amazing to have something like a LitMat 4 with a narrow beam angle built in. 

The Aadyntech holographic lens looks closer, but I wonder if it has the ability to narrow the focus of a light or if that is just further spreading the light?  

If anyone has any more info about trying to do a thing like this that would be great! 

 

 

 

 

It's definitely in the form factor of traditional diffusion, but there's definitely something else going on. It's clearly not a louver or eggcrate, so it really has to be something akin to a holographic lens. I have a sheet of this at my shop, I might have a microscope somewhere I could take a look at it under!

On 6/16/2020 at 4:56 PM, Brian Doran said:

This is just my gut feeling, but wouldn't having a focusing lens on each LED cause multiple shadow issues? A diffusion plane is really helpful for homogenizing the multiple light sources into "one" source. 

There are a lot of LEDs with individual lenses over the diodes, any fixture that uses 5mm-style for example has a lens built into the LED itself. Another example would be an Astra. But you're right, they do leave multiple shadows.

Have yi

1 hour ago, Joseph Tese said:

I have actually have recently been thinking about this a lot - And since there's so many softpanels on the market, I've been wondering why there wasn't at least a third party focusing lens like this offered for common form factors, or why it's not a standard offering from the panels themselves. The first thing I think of is Arri's intensifier, which essentially does the same thing. It tightens up the beam angle and concentrates the amount of light in front of the fixture. To me, the advantage here is not only the "increased amount" of light, but also probably greater efficiency (less-light loss) than what you'd get with a grid/honeycomb. Generally, I think it may be the case you don't get as much control as a grid. Aadyntech uses the same concept for their punch fixture, to achieve similar versatility as you'd want with a fresnel, via plastic focusing lenses. https://www.adorama.com/atpchlen055.html

have you seen Rosco Opti-Sculpt? It's brand new and is, I believe, a holographic lens sheet. A little expensive compared to normal gels, but it's pretty cool stuff: https://us.rosco.com/en/product/opti-sculpt

6 hours ago, Brian Doran said:

I'm not sure that this logic holds up. Peak photopic sensitivity is defined as being 555nm, which is a green color. Check out this luminous efficacy chart. Maybe I'm misreading, but it also feels like you are referring to blue light as being longer in wavelength, while the inverse is true. If anything, our scotopic vision is more sensitive to blue light than our photopic. Please let me know if I'm misinterpreting your post.

Ah you're right--I mistyped, meant shorter of course. I'll edit my post so as not to cause future confusion. Scoptopic vs photopic, that's kind of what I meant to say--if we light scenes in darker conditions (and most people also view content in darker conditions) than we'll perceive a bluer light better than warmer light (it's not peak sensitivity, but it's closer than red.)

52 minutes ago, David Mullen ASC said:

"Emotionally" a single candle flame is a "soft" source but in practical lighting terms, it is a fairly sharp source depending on the size of the flame.

I actually think this illustrates what James is saying here. When I think of, say, Barry Lyndon, I don't think of that movie as being lit by hard sources--in my mind it feels very "soft." But obviously when you actually look at stills the candlelight scenes are actually quite hard.

That said, I think it's a human perception flaw and likely shouldn't be something that is relied upon.

1 hour ago, James Compton said:

No pseudo science, here. I am speaking from an artistic perspective. I am referring to light absent of color. 

Firelight - soft

Incandescent - soft

Fluorescent - crisp

Quartz halogen - crisp

Metal Halide - crisp

High Pressure Sodium - soft

LED - crisp, Sharp

 I have seen every permutation of LED technology and the light always appears thin and sickly. Now, throw color into the mix and it still looks thin. I can quickly spot a scene shot with RGB LED's versus tungsten units with gels. My eyes can perceive the defecits in the aforementioned technologies.

TEXTURE is the word to describe them. Not a fan of LED's. I simply will not use them for photography. It makes it easier for all departments when shooting with a digital format. You don't have to like it or agree with me. That's just me.?

I weirdly understand what you're saying here. However, I would be very hesitant before bringing this up in a professional context, if for no other reason than it will cause confusion.

The reason is not because the light is actually softer, it's because the longer wavelengths are more visible to the eye and so it's just easier to see the harshness of the bluer lights. Additionally, bluer lights activate our photopic vision which makes that harshness even crisper.

The manuals of cameras always list the acceptable voltages.

From the DSMC2 manual: The 6-Pin 1B DC-IN connector accepts DC input power from 11.5VDC to 17VDC

Ursa Mini Pro: 12 V to 20 V

18 hours ago, Phil Rhodes said:

Well done on getting an open source project out there; it's something I'd repeatedly intended to do but never got around to.

Next, colour mixing. I might know someone who could help with that, if you felt like a collaborator.

Re PWM my concerns linger. Driving a large (multi-amp) load with 15-20KHz PWM is likely to create truly majestic amounts of RFI at audio-relevant frequencies, unless it's rise-time limited, in which case the problem becomes one of overheating the transistors. You can LC filter it but then you've basically built a DC converter by the back door. Possibly you could get away with building one in the shed, but nobody's ever going to be able to get a product that does that through compliance testing in any responsible jurisdiction (in China it's fine, apparently.) Nobody likes a buzzing noise, and in any case PWM at almost any frequency can create venetian blinds on rolling shutter cameras. I take your point that it can sometimes work, but I'm not comfortable recommending it as an approach.

I keep looking around for a low-cost DC converter with digital control - I suspect it's obvious why, but there aren't many of them. I found a couple with serial control but the response time was lousy; hundreds of milliseconds, which made fades clunky.

P

 

My little open source light pulls up to 6 amps and runs at 10Khz, absolutely nothing even close to audible whine. Remember that a lot of these driver modules and ICs have to be vetted in and of themselves, for example attached is the testing for the driver I chose. I haven't actually read any of these certs, I have no idea what they mean, but it's a far cry from "not being able to get through compliance testing." It's absolutely possible, and most of the fixtures you use on set on a daily basis have done it. Skypanels, LED Lekos, etc. are all PWM. Fan noise will most certainly be louder and broader spectrum than any whine.

Using a filter is a fine solution and actually can work well, but it limits the max brightness of course.

Another thing to consider is remote phosphor fixtures like the Cineos can use the phosphor itself to add some "photonic inertia" that smooths out the flicker. I've even seen this with regular diffusion at high frequencies.

And yeah, RGB mixing is definitely on my radar--but I'm wanting to wait until I have regular access to a colorimeter, as the fun part for me is figuring out the right mixing algorithm to look correct to the human eye.

6 hours ago, Phil Rhodes said:

HMI ballasts working in flicker-free mode are often a lot lower than 200KHz, but HMI ballasts are not PWM devices. They do not leave gaps between the pulses in the two mutually-inverted square waves that drive the lamp, so the light output is so near to continuous that it tends to work quite well at a wide variety of frame rates. That's not true of PWM dimmers and they are likely to cause problems under at least some circumstances.

I think I'm doomed to spend the rest of my life explaining this to people, but you really should avoid PWM dimming for movie lights. It may sometimes appear to kind of work, a bit, under some circumstances. Sort of. It remains a bad idea.

You can do linear DC dimming for similar money.

P

Forward: I've built dozens of LED effects for movies and shows around the world, and recently released my own open source LED hardlight project--which, OP, if you're not stuck with the LiteMat form factor, I highly recommend you check out:https://github.com/MadlyFX/OpenLUX-LED-Video-Light

Your skepticism of PWM dimming is obviously well founded, as we've all been bitten by the negative effects it can have. However, the reality is that after about 15-20khz, PWM dimming is, for every "normal" circumstance, flicker free. Obviously everything has a gotcha, and if you're shooting high speed, or stupid high shutter speeds of course you'll see flicker. But if you're doing that, you are likely already looking into High Speed lights (and LEDs likely won't be bright enough.)

The issue with constant current dimming is that it affects the color and temperature accuracy of the LED. If you look at a white LED datasheet, they almost always have a graph showing an correlation of color shift vs Current. They are designed to driven at one voltage and one current for optimal performance, and deviating from that does, nearly always, have negative consequences. You're trading flicker for accuracy, essentially.

Lastly, since CC dimming circuitry needs to be able to "take the full brunt" of the current the LED is pulling, it may need it's own additional cooling and does take up more physical space. All these reasons are why even the big players often choose high frequency PWM dimming versus constant current dimming, it's essentially a choice of "make it 100% good in 5% of circumstances, or 90% good in 95% of circumstances.

(Also you mention dimming LEDs with a DC converter board, which you can do, but just to clarify for OP, you want one that allows you to control the current, not just the voltage. Unlike Tungsten, LEDs are constant current devices, the voltage fluctuates to maintain the rated amperage.)

Also found this really great article: https://www.powerelectronics.com/markets/lighting/article/21861301/how-to-add-analog-dimming-to-virtually-any-led-driver

21 minutes ago, Alexander Sutton Hough said:

Looking for something cheaper for DIY. There prices are to high for DIY projects. If I am going to spend that much I would just go the full way and buy a litemat plus. 

I'd be worried that going with a cheaper solution will just get you low CRI, crappy quality LEDs. Might be fine for your application, I've gotten away with some quite bad diodes in the past, but the reality is good LEDs are expensive.

Lots of people do this with the Litegear strips attached to coroplast, it's a nice film-ready DIY ecosystem.

17 hours ago, Carl Nenzen Loven said:

Agreed. But then again, same as before pseudo discussion.

Arguing why you want film is a decision for producer to pay, arguing why you want anamorphic is for producer to pay...etc etc. I do understand this. But I think I rather just step off here.

You have proven your point, and yet again no one knows the result, so when this is all over I will trek to a rental house to test this out. Maybe I am completely bonkers and have no idea what I am doing, or maybe it will look great. We shall see.

C

You're right in that this industry allows a lot of experimentation and that there's often no "right" answer, but that flexibility only bends so far before it breaks. At some point you're just convincing yourself that an image is better because "art" when you're actually hamstringing yourself into a corner with a limited toolset.

The fact you mention you prefer one image "straight out of camera" shows you're not thinking about this systematically, because the reality is unless you're shooting live feeds there is essentially zero reason you should ever have to rely on an image straight out of camera. If you disagree...remember what I said about hamstringing yourself?

23 hours ago, Carl Nenzen Loven said:

As mentioned before...I appreciate the input but it is a pseudo discussion. You could even debate if you effectively actually get 4k from the S16, or rather a 2.5k upscaled, but that isn't the discussion. 

My goal would probably be to test it on a F35 and F3 just to see what the result is.

If the overall file and result is still sharper and better than a DSLR 4k, I might do it for my own projects still.

C

Look, you're comparing to a DSLR, which is fair, but also remember that you can get a Pocket 4K for less that shoots RAW--that's better than 4:2:2, that's even better than 4:4:4, it's RAW. AND you can bill clients for True 4K.

There's also more to life than sharpness. You'll likely go through this whole rigamarole to get 4K our of the F3, but you will most certainly find that if you had just gone with an A7III you'd have cleaner images overall. Remember, grain gets upscaled too.

The reason you're getting backlash is just that you're just trying to do a weird, unnecessary thing. If all you want to do is see how it looks, call up a rental house when Corona is over and go spend a day testing everything.

21 hours ago, David Peterson said:

Reality is even worse than you think, before you can get regular full rate work as a 2nd AC, you need to get experience as a 3rd AC / trainee. 

And you can't exclusively focus on grinding your way up the camera department's ladder to becoming a 1st AC and ignore your development as a DoP. 

So while you're focused on your bread and butter AC work, you still need to squeeze in indie work as a DoP whenever you can on top

Just wanted to chime in and say this is what I'm seeing several people do currently,  and it's working out quite well. Not just DPs, but directors, prop masters, etc. Work on TV shows full time as loaders or assistants, and in the process of doing so make friends who can help on side projects on hiatus and weekends, and money to fund personal projects. Eventually you get enough of that to build up a reel, which can be shown to the contacts you've made on your day jobs, and then you can skip the remaining 10 years of indentured servitude ?

It's tough because you're stacking extra work on top of days that are already 12-14 hours long, so you'll find out very shortly just how passionate you are.

Here are a couple other things to consider. First, art, like any creation endeavor, is 99% prep and 1% execution. Sure, an experienced artist can sit down and beautifully render a scene in minutes. But an experienced artist isn't working for $65/page.

An inexperienced artist, who doesn't know what they don't know, easily bites off more than they can chew--leading them to be flaky, or to really practice/think about what they're going to do, leading to them taking longer. It's easier to ghost someone than it it to admit they were wrong and apologizing for wasting their time.

And here's the thing: experience isn't a definable term. I have a friend who is an incredible illustrator, I've known him most of my life, he has a website, a portfolio, the whole thing. But he's still not a professional illustrator--it's still something he does as a side gig. He doesn't spend every hour in that flow state that allows full time artists to crank out amazing work on a whim.

Lastly, I agree that if they don't like the price, they shouldn't agree to the job. However, even if they do, think about the psychology of it. If you are walking down the street and see $25 (or $65) you're like hell yeah, I want that. But, you go to pick it up an a genie emerges that says you need to do 5 hours of work for it--you still want that money, there's just not a lot of motivation to earn it.

That's what's going on. By accepting that job, that's the equivalent of deciding to pick up the money, it's an impulse. Then reality sets in, and it turns out not to be such a good idea after all.

Kippertie Longtake mags are the only officially approved ones: http://longta.ke/

Have you tried prosupport@sony.com?

9 hours ago, Mike Krumlauf said:

He did send me examples but I dont want to share anything of his without his okay. The images he sent me, he told me it was on a digiprime wideopen.

 

Any advice you can send would be appreciated. I never ran into things like this.

Well, does it look underexposed? it's a 10 year old device, is he possibly just holding this camera to an unreasonable standard?

Can you post a frame grab? Is it just underexposing like you can with a modern camera, expecting to get a clean image?

2 hours ago, Barnaby Coote said:

My main concern would be the look. I already have a water based smoke machine that I got a long time ago, a martin magnum 850, its smoke eventually turns into a somewhat heavy haze, but indoors it takes too long to even out, it's very hard to keep the level consistent between shots and there is always a bit of graininess to it.

How do water based hazers compare to the df50 ? Would one really be any better than the martin machine I already have ?

What about fire systems ? I've never used haze in a public building yet, but I've heard smoke detectors are getting much more sensitive than before. I'd always err on the side of caution and ask permission first, but does oil have more of a tendency to set systems off than water based ?

Why not rent one and test it to find out?

Yes, they will set off fire alarms. Always check with your location about turning them off. They won't trip sprinklers, but they will set off alarms and smoke detectors no problem.

EDIT: Wanted to clarify a bit about water based hazers vs. foggers since they could be construed as the same thing, the main difference is how the fluid is introduced.

A fogger will pump fluid into a hot heat exchanger, the heat will rapidly boil the water in the fluid. The expanding gas creates pressure that forces the fluid out, vaporizing it. When in the air, the glycols in the fluid have a different refractive index than the air, bending the light that hits it and making it visible. That's why higher quality fog fluids have more "stuff" in them, they'll use multiple glycols with different refractive indicies, making the fog thicker.

A water based hazer relies on this same principle, but it also introduces an inline air pump in the fluid line as well as some kind of external fan. The inline air pump creates that pressure without relying on the vaporization of the fluid. This means less heat is transferred away from the heat exchanger and means the hazer can run for longer periods of time, usually indefinitely, without needing to stop and reheat. However, it means the vapor that comes out doesn't have as much "gusto" and can't travel very far without help. Thats' where the fan comes in, pushing the haze away from the machine, distributing it, and spreading it out.

1 hour ago, Stuart Brereton said:

 I would imagine that they've done that because of some imagined legal exposure or financial implication, rather than any concern for human wellbeing ? 

I would imagine you're correct ?

I did a shoot for ABC earlier this year and they were *very* picky, banning even certain types of water based fluids. I don't think Radiance 7 fluid would fly with them, for example.

For me, if I'm investing in a hazer/fogger, it's important it meets as many of these criteria as possible so I can rent it and make my money back--but OP may not have any concern like this.

1 hour ago, Stuart Brereton said:

I'm not sure that this is accurate. The relevant part of the SAG contract states that actors should be aware of safety precautions when working in smoke or haze, and that they have a right to see the MSDS for the products being used, as well as a right to fresh air breaks when necessary, but it doesn't outright ban any particular type of haze or smoke fluid.

The most commonly used haze, DF50, is a light mineral oil. The MSDS states that it is non carcinogenic, and safe to breathe under normal use.

The Contract Services safety bulletin does list which substances are banned and which are ok. Highly refined mineral oil (such as DF50) is ok to use, subject to the usual provisos of limiting exposure, etc, etc

You're correct here, but it should be noted the allowed concentration of oil haze is less than water based. However--and this has been my personal experience over the last several years--studios set their own restrictions beyond what SAG does, and these almost always include the banning of oil haze.

Fox and Disney do ban mineral oil haze specifically. I'm almost always asked specifically to make sure fog/haze will be water based. This obviously really only matters for union shoots, if you're just making movies with friends, use any means you want ?

Here's a copy of the info from a Fox call sheet:
 

Quote

 

1. The following substances should not be used:
a) Known human carcinogens including any particulates of combustion,
including tobacco smoke (except where such smoke results from the
smoking of tobacco by an actor in a scene);
b) Fumed and hydrolyzed chlorides;
c) Ethylene glycol and Diethylene glycol;
d) Mineral oils;
e) Aliphatic and aromatic hydrocarbons including petroleum distillates;
f) Hexachloroethane and Cyclohexylamine;
2. The following substances may be used:
a) Propylene glycol, Butylene glycol, Polyethylene glycol and Triethylene
glycol. Other glycol products should not be used (see c above);
b) Glycerin products [Caution: Glycerin and the listed glycol products should
not be heated beyond the minimum temperature necessary to aerosolize
the fluid. In no event should glycerin or glycol be heated above 700
degrees Fahrenheit];
c) Cryogenic gases (e.g., carbon dioxide, liquid nitrogen) may be used but
care must be exercised to avoid depleting oxygen levels, especially in
confined areas. Use care also to avoid adverse effects of cooled air on
exposed persons

 

Also of note here is polypropylene glycol is always banned as well, so be careful before using any of those new tiny foggers that are actually converted vapes.

52 minutes ago, Phil Rhodes said:

Is there some huge difference between what happens in the USA and here, then?

In the UK most of the stuff I've encountered (in live events, clubs, theatre and film) has been the same thing that goes in more or less all smoke machines (and vapes), which is a mixture of water and some sort of glycol, which is sort of oily but definitely not a mineral oil. Stuff designed to create haze rather than smoke is just watered down more, heated slowly in a low-capacity machine and blown through a fan. Ultrasonic crackers using actual oil went out some time ago, mainly because of the horrific mess they make.

Nobody uses crackers anymore, but an oil based hazer like a DF50 isn't a cracker--it's essentially a very, very fine spray nozzle that atomizes the oil.

It's not so much that's less smooth or even, it's just more visible in thicker concentrations. An oil based hazer will create practically invisible haze that catches light beams. A water based one will create a, well, hazy atmosphere.

Water based haze can stick around a long time, but I've actually found the number one thing that affects it's longevity (aside from air conditioning) is people. If you have a party scene with 50 people all dancing, their heavy breathing will inhale that haze out of the air.

An Antari Z-350 would be my pick, a great machine, super portable, highly adjustable, and built to last. And not too expensive.

Most people would prefer the look of an oil based hazer, but if you ever plan to use this around SAG actors, it will have to be water based. Oil based hazers are also very expensive.

The trick is whatever level you set on the hazer will determine the thickness of the haze. Seems obvious, but it means a thinner haze will take longer to fill a room. Just something to keep in mind.

I like the fluid from Froggys Fog as an aftermarket option, and they have their own machines that are quite good as well.

I think the key is, no matter what you do, to make sure everyone in the chain that deals with the image knows what you're doing.

You will get cleaner images and thicker negatives if you shoot as you mentioned in your original post, by exposing to a certain IRE and bringing it down in post. By doing that, you're "spreading" that data over more of the available dynamic range. You'll of course lose some when you go to grade the image, but it'll give you more flexibility as you do--you'll find you can push the image more.

However, as others mentioned, if a client is going to see the raw footage, or you need to delivery ASAP without grading, than of course expose for the look.