Dom Jaeger

Hi Jean-Louis, you and Tom seem to have worked it out already, but for what it's worth, I have specs for the BL4s - I think it's pretty similar to a BL4 in terms of current draw. The camera movement alone should draw 1.8 A. At 24/25 fps with a 400' load the draw should be 2.5 - 3 A. Of course, if you're running enough accessories from the camera accessory socket (lens light, heated eyepiece, split, mini-monitor, Preston etc) you can easily double that. I think the supply fuse is 7 amps. 12V 7Ah lead-acid block batteries were pretty standard for these cameras, but if more weight isn't an issue and there are a few accessories to power a 12Ah cell is better. If you're going with NiCads, you should be OK with 14.4V (we never had a problem). You're definitely fine with 13.2V.

Well this honest-to-goodness optical guy thinks you're pretty spot on Dan.. B) Yes, the tolerances are fairly tight. The rear lip of the mount needs to fit snugly in the camera mount cavity, so that the lens is centred and can't move around, but obviously you want to err on the side of too small. Undercutting where the rear of the wings meets the lip will help the lens seat properly. Other than that the critical things are flatness of the mounting surfaces (mount to lens seating, top and bottom of the wings - ideally within 0.01 mm) and the thickness of the mount wings. Too thick or thin and the PL locking ring either won't slide over the wings or slides too far past. I think 2.00 mm is the upper limit. The depth will be the tricky thing. Proper PL mounts are machined about 0.1 mm under where the exact back focus should be, then shimmed the rest, so you can set it exactly. It's easy if you have access to a collimator, otherwise you have to play with shims until infinity focus lines up. You can make your own shims out of thin plastic sheets with a compass cutter and a hole punch. I'm guessing you'll be just eye-focusing when you come to use the lens, so as long as you can reach infinity you'll be right. Not an easy thing to fabricate though.

It's probably the most interesting ratio there is (and there are some very interesting ones out there!).. The easiest way to visualise it as a rectangle of sides 1 and 1.618 (or 0.618 and 1 - the ratio is the same). It creates a very pleasing shape, but the magic comes when you divide it into a square and another rectangle. The smaller rectangle will have exactly the same proportion as the larger rectangle. Segment the smaller rectangle with a square again and you are left with an even smaller rectangle of the same proportion, ad infinitum. You can do the same thing with a line, dividing it into a smaller and larger portion with the ratio 1:1.618 (or 0.618:1). The proportional relationship of whole line to large section is the same as that of large section to small section. There exists only one point in the division of a line into 2 unequal parts that creates this proportional symmetry - the golden section. So it can be used not only as a framing shape, but also to divide linear space, or create more complex forms such as spirals. In nature it creates patterns that remain the same proportionally no matter how big they become. It also pops up in all sorts of seemingly unrelated mathematical areas from the Fibonacci series to tiling patterns. I suspect we respond on some subconscious level to the proportional symmetry of the ratio and find it aesthetically pleasing.

Lens coatings are generally applied layer by layer in a vaccuum chamber with the coating materials vaporised and allowed to condense evenly on the element, at temperatures of several hundred degrees. A more recent technique involves bombarding the surface with ions, which doesn't require high temperatures. If you do a tour of a lens manufacturing facility the only room you're not allowed in is the coating lab - it's the cleanest room in the building. The tiniest contamination and the whole process has to be redone. Like Tom says, you often need to heat up a lens during a service and they can take a fair bit of heat. But I think sustained heat is not so good - it can dry up lubricants and I've seen the edge blacking of elements quickly deteriorate (causing an interior speckling effect that rings the glass) after shoots near volcanoes for example, though that could also be the atmosphere. The coatings seem unaffected though!

It should be centred. Can you post a photo of how it mounts to the camera?

Hi Andrew, On flat-base cameras the leatherette at the front of the base peels off, and the plate beneath is removed to screw on a slide block that holds the rear spacer of the matte box rods. On round base cameras a flat base adapter (BASOU) with a built in slide rail screws into the underside, and the matte box attaches onto that. The slide rail can be adjusted for centering. I've only seen the flat-base version myself, but it's all covered in Andrew Alden's Bolex Bible, quite a handy resource, especially for accessory info. You can make your own mattes - the original assembly was supplied with sheets of acetate and black cardboard for that very purpose.

Yes for very high speeds and 1000 ft loads 12V batteries are often not enough. On occasion we've used 14.4V batteries without problem so 13.2V is definitely fine. The upper limit of the motor electronics tolerance is around 35V I've been told (so two 14.4V batteries fully charged are sailing pretty close to the wind).

Hi Jonathan, look you don't need to be too fastidious, those figures I gave were in the interests of accuracy and to give you an idea of how much a NiCad should be discharged, but they're pretty tough batteries. Without a low battery warning or meter it's pretty hard to monitor the voltage level for optimum battery life, my point was mainly that you don't need to keep discharging the cells after the speed dips. The danger with bulb discharging is that it will just keep draining the cells, whereas most appliances reach a cut off point where the voltage drops too low to keep working. It would be good if the battery re-celler can check your charger as well, but if it's working OK an overnight charge should be fine. I'll assume that the camera is an Arri 2C, which should draw 2A without a load and about 3.5A with a 400 ft load. The constant speed motor should keep speed until the voltage drops to between 12 and 13V. (That's a little past the 'recommended' discharge limit, but it won't damage the cells.) So if your new cells are 8 Amp-hour capacity the battery should run a 400 ft load for over 2 hours before the frame rate dips, at which time they'll be well ready for recharging. If it's an old power cable, or the mag take-up tension is too stiff you'll draw more current and get less run time. If it's significantly less I'd get the charger, cable and camera checked.

The 'recent scam' of experimental, non-narrative cinema (labelled as such) probably starts with films by the Dadaists, Surrealists and other revolutionaries of the 20's, the best known examples being Un Chien Andalou and Man with a Movie Camera, both from 1929. Dali, Bunuel, Vertov - all poseur hacks I guess... :blink: Malevich painted his Black Square back in 1915, so the total abstraction scam has been going nearly a century now. Just personally, I could stare at a Rothko for hours, but I'm a bit of a wierdo. As far as today's mainstream cinema goes, I thought Children of Men really pushed the envelope stylistically, in a way that enhanced the film's narrative. I came out of that one blown away, even though I don't generally like too much hand-held.

At what voltage is the frame rate dipping? What's the camera supply voltage meant to be? Unless your battery voltage is too low for the camera or you're dropping voltage over the cable or connections, I would have thought by the time the frame rate dips the battery should be ready to recharge. It doesn't need to be drained completely flat, in fact that will shorten its life. The battery capacity will give you an idea of how long it should run for - if it's 8 Amp-hours for example it should supply 2 Amps for about 4 hours, before the voltage drops 10-15% below its nominal level and may start to affect the appliance (at least while the cells are relatively new). You generally don't want to discharge a NiCad battery much more than about 15% below the nominal voltage (each 1.2V cell down to 1.0V), 10% below is roughly the recommended discharge limit for maximum longevity (down to 1.1V per cell). In your case (16.8V) you'll get the longest life out of the cells if you recharge when the battery hits 15.4V, and avoid draining it below 14V (measured under load). With modern NiCads it's not too bad if the battery is regularly being only partially discharged before charging again, as long as every month or two the cells are exercised with a full discharge/charge cycle (down to 1.0V per cell). A very occasional deep discharge down to 0.5V per cell can be useful to rebalance and recondition the cells but it should be a very low discharge rate, otherwise you risk cell reversal and internal shorting. All of which is to say, if you use bulbs to fully discharge your battery belt, monitor it with a voltmeter to avoid draining it below 14V.

Wow Steve, you're a dude! Hats off. I'm a sucker for old school myself - just about everything touted as new and improved always seems to involve something else being lost, and it's often only realised when it's too late. The price of progress I guess. But I'm curious as to how many other people (other than Simon B) ) are still cutting traditionally. My impression was that these days you can't even give that gear away. There's a lovely old chap in his 80's who regularly drops in to my work to get an old lens or camera serviced by me (even though he doesn't use them anymore) and give me another standard 8 camera he's dug up for my collection. He was a cine editor for 40 odd years, and the depth of his knowledge is astounding. I always pepper him with questions. But it makes me sad to think that his knowledge and skills are generally considered obsolete and will pass with him.

What's interesting in this case is that footage from 2001 is being used in a legal defence against Apple, who are claiming Samsung blatantly copied their iPad design. It concerns the form rather than the technology behind it. Quoting from an article in The Age: "Mark Summerfield, a senior associate with Melbourne intellectual property law firm Watermark, said the Apple patent referenced in the Kubrick defence is a design patent that protects the form or physical appearance rather than function. ''Generally, science fiction is not legitimate prior art to a utility patent, because it does not provide an 'enabling disclosure' - it does not inform the public how to make the fictional apparatus,'' Mr Summerfield said. But he said there was no reason why science fiction could not be ''invalidating prior art'' to a registered design." A device from the 70's kids sci fi show "Tomorrow People" (which I used to watch avidly!) was also cited. I've always found the speculative design element of sci fi to be one of its most interesting aspects, starting with the fiction of Welles and Verne, but more thoroughly visualised in movies - from the fembot in Metropolis to the drag screens and interactive advertising of Minority Report. And I'm bitterly disappointed that the hovercars I was sure I'd be driving by the time I grew up still haven't eventuated. They'll probably come out just in time for me to get a hover-walking frame. :huh:

http://news.techeye.net/hardware/stanley-kubrick-invented-the-ipad-in-1968 Bad news for anyone who is busy inventing a sonic screwdriver, holodeck or re-hydrateable pizza.. B)

If you weren't already planning to do so, it would be a good idea to spend some time at the rental house familiarising yourself with the system. You can download the SL manual here: http://www.davidelkins.com/cam/manuals_software/manual_files/moviecam/sl_manual.pdf If you're loading, fitting the film core onto the mag spindle properly can be a little tricky, so read up on that and practice it if you can. (It's similar to the coreholder in Arricam mags, if you know them.) It might also be worth checking that the digital footage readouts on each mag are working - the internal memory battery gets recharged when a mag is mounted to the camera, but may have died if it hasn't been used in a while. Though that should be something the rental house has checked.

You need to take out the baffle plate to remove them. Have a look at these webpages: http://www.k3camera.com/k3/krasnogorsk-3-disassembly.php http://www.k3camera.com/k3/k3s16mm-install.php

Hi John, I use a germicidal cleaner that I got from Zeiss years ago - "Fungusreiniger" says the label, but no mention of the specific agent or ingredients. You dilute it with ethanol, and leave it on the affected surface for an hour. It works very well - fresh fungus disappears without a trace. Of course if the fungus has been there a while it will have thoroughly etched into the coating, but the germicide will stop it spreading. I'm not sure if Zeiss still sells it, but you could inquire.

Hi James, there's no single test, but here are a few things you can do to check the important stuff: Load up the camera with some dummy stock and with the camera and mag doors open check that everything is running smoothly. A can of expired film is good for this. It's also a good way to get familiar with loading and lacing (in particular the lower loop needs to be correctly set). Check that the doors all seal well, and that the mags and lens attach firmly. Remove the film and check it carefully for any scratching. Don't worry about occasional random scratches, look for continuous or repetitive marks. Light scratching outside the image area or on the backing you can probably live with until you send the camera to a tech for the Ultra conversion. Adjust the eyepiece diopter so the ground glass texture is visible, set the zoom to the long end at maximum aperture and focus on a subject 6 feet away. Check that the lens scale matches the distance. Zoom to the wide end and check that the subject remains in focus. Try the same thing focusing on a very distant object (effectively infinity on the lens scale). A discrepancy could be due to either the lens or the ground glass depth, if you have another lens it can be helpful to compare them. Shoot a registration (or steady) test. I described the procedure in this thread: http://www.cinematography.com/index.php?showtopic=52742 Remember to close off the viewfinder eyepiece if you're not looking through it when filming (a good idea during a reg test in case you move the camera with your eye pressure. The camera should be very firmly supported. At the same time you could check the ground glass framing by marking the framelines visible through the viewfinder on to the test chart, which will show you where the framelines are relative to the camera gate aperture when you view the test. Shoot a focus test. Easiest thing is probably a sheet of newsprint taped to a tilted board. Light it so you are using the the lens at its widest f-stop, where back focus/flange depth is most critical. Focus on a circled word in the middle, start at the long end and work to the wide end. Again, a discrepancy could be the lens or the camera flange depth. Without a strobe timing gun, you could check the camera speed by either timing how much footage runs through in a certain time period, or filming a clock that displays seconds. Obviously the longer you go the more accurate your measurement will be. The out-of-sync warning light on the door side (and the 'S' displayed in the viewfinder) should tell you if the camera is not running to speed though. Listening to the camera during film tests will give you an idea of how noisy it is, whether sound work is possible, or when you might need a sound barney. Most critical are the scratch test, registration test and focus checks. Other potential issues like light leaks or focus breathing in the gate will show up in the filmed tests. To properly check focus issues, the lens collimation and camera flange depth and ground glass depth need to be checked by a tech with a collimator. Good luck with it!

Yes, depending on their design and range, some zooms will have their fastest f-stop restricted as they approach the long end, as the size of the optics limits the entrance pupil diameter. Some older zooms allowed for a faster f-stop at their wide end, but the image would visibly darken if you zoomed in. To maintain a constant aperture the iris needed to be stopped down to the long end limit or beyond.

Oops :rolleyes: That was meant to be "In a zoom the entrance pupil diameter will expand as the focal length increases".

It can be a very confusing subject. Mathematically speaking, the factors affecting depth of field are the distance to subject, focal length and aperture. (There's also the circle of confusion value which changes depending on the viewing criterion and format and how much loss of focus is still considered acceptably sharp, but that's outside the lens factors.) Now because of the way subject distance and focal length are related, if the subject size remains the same across different focal lengths (by altering the distance), those 2 factors cancel each other out leaving only aperture as the determining factor of the depth of field. This is what David was explaining. The relative aperture or f-stop is is a measurement of how much light is transmitted through a perfect lens and is defined, as you said, by the ratio of the focal length to the the diameter of the entrance pupil. In a zoom the entrance pupil diameter (basically the image of the aperture as seen from the subject space) will contract as the focal length increases, maintaining a constant f-stop. So yes, fundamentally the entrance pupil diameter, the focal length, the distance to subject and the aperture all affect depth of field, but because these factors are all inter-related, the simplest way to understand it is: for a given format, with a constant subject size (and a chosen circle of confusion), the only factor determining depth of field is the f-stop.

That is sometimes true, but criticism can also be an artform in itself. A particularly insightful critique can be more valuable than a thousand shallow plaudits to an artist who wants to grow. But criticism has its place - you don't critique a child's drawing, or a love poem from your girlfriend. And it needs to come from an informed perspective. We judge things differently depending on the intent behind them and our expectations of that intent, so if it's a big dumb action movie we judge it on how entertaining it was, if it's a low budget zombie flick by a first timer we might judge it by how inventively the genre has been tackled. But if it's a high brow art-house film you wouldn't criticise it for not having enough car chases. Which is sort of the attitude of the original poster (only in reverse). As many have pointed out, B movies have their place (for a number of reasons), and until you've tried to make a film yourself or at least have an understanding of the enormous challenges involved, criticising them for existing is a form of ignorance. I get annoyed when a film pretends to be something it's not, but that's probably more often the fault of the cover art or marketing.

To properly set the ground glass depth the camera needs to be mounted on a bench collimator, using a test lens that has itself been very finely collimated. A 50mm lens has too much depth of focus (at the image plane), it will look sharp even if the back focus is out by several hundredths of a mm, which is more than the ground glass tolerance should be. I use a test lens of around 18 to 25 mm focal length, which has a shallower depth of focus, and so allows for a more accurate setting. Judging sharpness by eye through the viewfinder with an 18mm is very difficult, which is why a collimator is essential. It's been a while since I worked on a BL3, but I think the 2 screws you've labelled 'B' are just plugs to cover the access holes. Underneath are two nuts that secure the slotted depth adjustment shafts. To adjust them, the nuts are undone half a turn, and the shafts minutely turned, equally to maintain flatness, then locked again with the nuts. It helps to have a special tool, basically a slotted driver within a socket driver, to hold the inner shaft and prevent it turning as you lock the nut. There is also a tool (and a complicated procedure) to measure flatness (necessary for even focus across the ground glass), but unless the shafts have been fiddled with, the ground glass should be flat from the factory, so equal adjustment of the two shafts will keep it that way. The centre screw is an excentre to adjust horizontal framing, beneath the ground glass are two more screws to adjust vertical and twist. Without wishing to sound like a party-pooping disciplinarian, as a rule whenever a camera screw has been sealed with paint (like the green stuff in your pictures) it is often a precisely set adjustment that shouldn't be fiddled with outside of a technician's bench. It's very easy to introduce more problems than you started with..

In my experience, visible specks in the viewfinder are usually either on the groundglass at the top of the prism (accessible when you rotate the turret and swing out the prism), on the optics just above the groundglass (harder to reach) or in the eyepiece. By swinging out the prism while looking through the viewfinder you can see if it's on the groundglass. To clean it, try blowing it with a puffer or compressed air before resorting to lens tissue and isopropyl alcohol. The surface is very easily damaged, so avoid rubbing it - if a single swipe doesn't work , probably best to leave it. By adjusting the eyepiece diopter you can see if it is in the eyepiece optics (the speck will rotate). It won't affect the film, so you could just live with it. The only optical surfaces that really need to be clean are the front and rear lens elements, and the front and rear surfaces of the prism, none of which will be in sharp focus through the viewfinder.

No worries Deepak, glad to hear you worked it out. Thanks for posting your findings, often people never report back and you're left wondering what happened.. Namaste :)

Sam Fuller was a great example of that. On the surface a film like Shock Corridor screams B movie - melodramatic, limited sets, average actors - yet he managed to sneak in some searing social critique and produce a truly subversive piece of art. His war films were similarly deviant - despite the appearance of a conventional B grade battlefield movie they often slyly condemned bigotry, racism and the collateral curruption of innocence, making them essentially anti-war (or at least anti the usual propaganda a government uses to convince its populace to fight one). It's likely an A movie at the time couldn't have got away with stuff like that.