Dom Jaeger

The main thing a lens specifically designed for digital sensors will be is telecentric (or more correctly near-telecentric), which just means that the light rays coming from the rear element are fairly parallel. Film emulsion doesn't care what angle a light ray hits it, whereas a sensor photosite does. Older lenses from the film era with tiny rear elements and shallow exit pupils (often wider angles) can induce colour fringing or vignetting when used on digital sensors. You can quite happily use modern lenses with film, the only issues are when the rear element protrudes too close to the film plane and can hit a reflex mirror, but despite a brief dalliance with this sort of design in lenses like Angenieux's DP zooms or Panavision's Primo Vs, most manufacturers have gone back to allowing more clearance for 35mm format lenses. Large format lenses however are now often designed with shorter flange depths, since the cameras are almost all digital, and they can utilise shorter flange depth mounts like Arri's LPL or Panavision's SP70. The irony of companies releasing "digital" lenses is that many people prefer to use older lenses that were designed for film anyway. As far as lenses designed for B&W goes, I don't see what specific attributes you might want in a B&W lens that you wouldn't also want for colour. Many lenses from before the 50s were probably designed with B&W film in mind, which is possibly what Joe Dunton meant, but they could certainly still be used with colour film. As lens design progressed, you had aspheric or APO lens designs which better corrected for a larger range of wavelengths, but they will also make a B&W image sharper.

More to the point, does anyone still have spare imperial focus rings for all those focal lengths, with the matching scale letters (the small letters next to infinity that determine the spread of the scale, which is matched to each lens)? Last I checked, Zeiss had very few spares for these lenses.

All the MOS Arriflex cameras - 2C, 3C, 35-3, 435, 235 - can run in reverse with most mags, also the Arriflex 535 and Arricams. Mitchells will run in reverse too. You can use a hand crank to rewind a Bell &Howell Eyemo, but only a few feet as the feed spindle does not rewind the film and you are also winding up the spring when reverse cranking.

Only the 10mm is RX, the 16mm and 25mm are described as AR.

Yes they look normal. With the first two Visifocus lenses, when you stop the aperture down, the little holes should progressively turn orange, to show you roughly how much distance either side of your focus mark should be within the depth of field. The third lens has a similar function, except instead of orange holes you just have the white lines extending to show depth of field.

Here’s my slightly jaded take, and as a lens tech not a DoP. The original Optimos were very high quality cinema zooms, designed for rental houses back when everything cinema related cost a bomb but was made with few compromises. They still work well after 20 years, as long as they get a bit of maintenance. The new Optimos are similarly top of the line. The Optimo DP zooms were a response to the new digital revolution (initially they called them Optimo “Rouge”) and were priced at around half of what an equivalent Optimo cost. They were close in image quality, but made to lower standards in materials and build, with a large rear extension that helped reduce design compromises but made them incompatible with film cameras. Since discontinued. The Optimo Style series were basically the DP series expanded in range and reverting back to a standard rear protrusion. Again, lower cost to appeal to the owner/operator market and the overall lower manufacturing standards of the digital age, but benefiting from advancements in optical design. No longer manufactured. The EZ series are a modular system designed to be modifiable for different formats and applications, including ENG. From my evaluation, well below the standard of the Optimos, but still good enough to be used on major movies. They tend to be even cheaper than the Style series. These days optical design is at a point where companies can make very high MTF lenses for pretty cheap, but the compromise is in build quality and the artistry that used to go into lens design. I find a lot of modern glass a bit bland, like a computer just met some MTF goals, and the build quality is such that you won’t be using these lenses in 30 or 40 years like you still can with an older Angenieux or Cooke zoom. But that’s a common story with modern manufacturing.

OK, that’s great, the camera seems to be running pretty normally. They all slow down a little at the end, particularly when under a load (ie transporting film), but a camera that hasn’t been lubricated in years will slow down more. The lack of lubrication will also cause wear to the bearings, which over time creates more drag. So a service is needed. If there is already a lot of wear, or the spring motor itself is tired, a service may not improve it much, but usually they come good. When the camera runs with film, there is a load added from both the claw pushing the film, and the take-up spindle slipping as it winds on the film. You can simulate the load by holding the take-up spindle and stopping it turning as the camera runs. A good, serviced camera should maintain speed when you add this load, up until maybe the last 5-10 seconds of the spring duration, when it might start to slow a bit.

No that’s not normal, and the scratching is bad. What model is it (serial number)? Are you sure you loaded the film properly? You can leave the lid off and run some dummy film through to check that the loop stays centred between the loop formers. Try to see where the scratches come from. It’s a good idea to find an original Bolex manual for the model you have online, there are quite a few around for free. But a service is a good idea anyway. In Europe you can contact Simon Wyss in Switzerland: https://www.filmmechaniksimonwyss.biz/english/ or Guido Wilhelm in Italy at wtv@fastwebnet.it There may be others who people can recommend.

There is some good information on that site, but also some misinformation, typos, and misunderstandings like this one. I tend not to recommend it as a reliable source of info. A lot of Bolex literature simplified things like exposure times in order to have nice round numbers. The early Bolexes had a shutter angle of around 172 degrees, but at 16fps this works out to be 1/33 second exposure time. To make things simple, the Bolex manual just rounded it down to 1/30 second, which is why some reference guides reverse calculated a shutter angle of 190 degrees. In the same way, the actual shutter angle of a H16 reflex Bolex is around 130 degrees, which works out to be a tad over 1/66 second at 24fps, but to simplify things the manual rounded off the exposure time to 1/65 second (or 1/80 adapted for the prism loss). When you calculate the shutter angle for 1/65 it turns into 133 degrees, hence the confusion. But as Joerg said, the difference is negligible in terms of actual exposure. Even the difference between 172 and 190 degrees, which seems a lot, works out to be about a fifth of a stop. The overexposure actually probably helps account for the internal light loss of the lens, which can be at least that much.

Fair enough. I hope you get back results that inspire you to continue!

If you have a Supreme, you need to meter for an exposure time of 1/60 sec if filming at 24fps, or 1/40 sec for 16fps. Err on the side of over-exposing, ie a smaller f number on your lens. The shutter angle changed around this time due to a new pulldown claw design, so this information is correct if your camera has the newer trailing claw. It should have a serial number above 100401.

Hi Jon, I pretty much service anything except Super 8 cameras. But I'm very booked up, minimum 2 month turnaround, and I will shortly stop taking on new jobs to catch up.

Most zooms like this lose around a third to half a stop. Damaged coatings or internal fog will add more loss. I'd probably rate that zoom at about T2.2. As a general rule, primes lose less than a quarter of a stop, modern zooms a sixth to a third, and older zooms between a third and two thirds of a stop. The number of elements play a part, so larger zooms will lose more.

I don't want to crush your enthusiasm, but if you can't afford $120 for a fairly essential part of the camera, how are you going to afford the film, processing and transfer costs? Have you looked into the costs of shooting film? You'll spend that much on your first 100', which will give you a couple of minutes footage. There was a small magnifying eyepiece part that screwed into that opening for the viewfinder so you could use the top focus port without a viewfinder, but they are hard to find too. You can simply use the lens focus distance scales to focus and hope that they are reasonably accurate. For framing the side finder has parallax correction as Jon described. You can use a phone app for exposure rather than buying a meter if you are very cash-strapped. As a tech, I generally advise people to have their newly acquired vintage camera and lenses at least checked over, and ideally serviced before they spend money on film and transfer only to find an issue after the fact. Unfortunately film is an expensive hobby..

The Astor, The Sun Theatre and Cinemateque at ACMI are the main places still showing film prints. The Astor website appears to be down at the moment, The Sun is showing a 70mm print of Dunkirk on the 1st and 4th of June, Cinemateque is showing 35mm prints of What's Up Doc and Interview With A Vampire in late June: https://www.acmi.net.au/search/?search=35mm print IMAX Melbourne has a 1570 projector, but the next screening isn't until Oppenheimer in late July. Check the AFW website for possible future screenings of artist films, they are a collective of filmmakers who shoot, process and print mainly 16mm film. They also have workshops sometimes.

Those 2 perf dimensions are smaller than most 2 perf cameras. The Techniscope full aperture was 22.6 x 9.47 mm, modern 2 perf cameras can go wider, but the height is still the limiting factor. The 2 perf 2.39:1 ground glass frame on cameras like the Aaton Penelope or Arricams is 22.35 x 9.35 mm. 3 perf 2.39 is only 1.15x larger in area than that. Even if you extract the full S35 gate width of 24.9mm from 3 perf (24.9 x 10.4 mm for 2.39), ignoring the ground glass framelines, it's still only 1.2x the area of the Techniscope gate. There are definitely advantages to shooting 3 perf 2.39, but the increase in area is not enormous. To put it another way, compared to 3 perf, 2 perf uses 33% less film to deliver an image 13 - 17% smaller in area.

You seem to have arrived at the correct solution already, but I'll add my 2 cents. There are three calibrations that are critical to reflex film cameras working as they should: 1. The camera flange depth 2. The ground glass depth, as reflected off the mirror - which should match the nominal flange depth 3. The lens back-focus collimation, which should match the nominal camera flange depth If you only use eye-focussing, then the first two calibrations are the only ones really essential, at least for lenses that aren't zooms or anamorphics. If you want your focus marks to line up, and be sure that they will reach infinity, then you also need the lenses collimated. Professional crews always use lenses with marks they can trust, so they can tape out if needed and also as a double check for eye-focus. Wide angles especially can be hard to judge sometimes just by eye. To properly check all these settings on a professional grade camera like an SR2, you really need a technician with the right depth gauges and an auto-collimator. They should be able to check the camera and a set of lenses in under an hour.

The take up should slip as the film winds on. If it’s too easy to slip, any obstruction in the magazine throat or in the loop could cause it to slip too much and not take up properly. Or if the take up spindle is sticky from dried lubricant the take up may not be turning properly. Run the camera with the door and mag lid off, using dummy film, and observe what’s happening.

I don’t recall if Ultra 16 focus scales are the same (I expect they are), but Ultra Primes, Super Speeds, Standard Speeds etc all use scale rings that come in different calibrations. There should be letters near the front infinity mark that identify them - HH or JJ etc. If you don’t use the matching scale ring, the marks will not line up all the way from close focus to infinity.

You don’t want to hand crank then, you want a spring motor camera. The most obvious candidate is an Eyemo, super durable and steady. Otherwise, for a really small package, look for a Kinamo. Just make sure it comes with the cartridge/magazine.

You could adjust your camera’s flange depth but if it’s the lens that’s out then you will be offsetting your camera for one lens and all your other lenses will be out. Perhaps not by much, but it’s not really the way to do it. Ideally you set the camera depth to the Arri PL standard and then any correctly set lens should work. If all your other lenses seem ok I would probably leave the camera alone and just try to tweak the lens, but you probably need a tech to do that. Maybe Camwerkz, who are a Singapore rental house with a service department?

Back-focus absolutely affects infinity focus. The way almost all old lenses focus is the same - at infinity the lens is positioned closest to the sensor/film plane and by shifting the whole lens further away you focus closer. If either the camera flange depth (distance from mount to sensor) or the lens back-focus (distance from lens mount to focal plane when set to infinity) are out of tolerance then the focus scale will be shifted and the lens will either go through infinity or it won’t reach it. If you can’t reach infinity then the lens is sitting too far away from the sensor. The shorter the focal length, the more an error will show up. This is because a long focal length needs to move a lot further away from the sensor to focus than a wider lens. You can notice this when you focus an old telephoto compared to a wide angle - the long lens will shift quite a lot as you focus from infinity to minimum, while the wide lens will barely move. So your 18mm will be more affected by a small back-focus error than your 50mm. It could be that the adapter is a little out, or your camera flange depth, or the lens itself needs adjusting (if you just bought a lens from eBay there is no guarantee it is correctly collimated.) It could be a combination of these factors. Or (and this is common in old lenses) there could be some wear causing play in the lens focus threads - try pushing the lens closer to the camera to see if infinity gets sharper. The OLPF can sometimes affect the perceived focus of wider lenses slightly, but any error should go away if you stop the lens down a couple of stops. A lens tech or rental house service department can check all these things pretty quickly on a collimator or lens projector.

If the sprockets are not properly timed with the claw when auto-loading then when you open the loop formers the loop will shift up instead of being centred, causing a short lower loop. You can manually reposition the film after auto-loading to centre the loop, but to get it set up right a Bolex tech probably needs to adjust it. Basically the rotational position of the sprockets needs to be set so that as the film feeds through the perf gets immediately picked up by the claw and then by the lower sprocket. It can be tricky to get right. If you try to set it yourself be careful to maintain the sprocket height position as well, since they can sit higher or lower. This is assuming the lower loop is immediately short after auto loading, and doesn’t shift after a while of running. That would be a different problem.

Those gears are made from fibre reinforced resin, very common in motion picture cameras from this era. They are used in the mirror drive gear and intermediate mag drive gear of Arriflex 2Cs and the sprocket drive gears of Arriflex 16Sts, among many other cameras. One of the names for this material is Tufnol. They are very commonly used as spur gears paired with a steel gear, in order to dampen noise and vibration. The material is very strong and wear resistant, but has some elasticity, allowing it to be uniformly shaped against the steel gear. For slow speed applications like movie cameras they are usually run either dry or with a light application of grease, oil is normally used for higher speed applications. On the Arriflex 16St for instance, the bearings for the fibre gears have oil tubes leading from an oiling well, but the gear teeth themselves are dry. On a 2C the gears are greased. I’ve yet to see them worn. Whether the East Bloc used the same quality of material as Arri I don’t know. 3D printing gears will solve the problem in the short term, but I’d be curious to know how the gear will last over time, or under more load like higher frame rates. We 3D print a variety of things where I work, but invariably the only gears that work well are ones with fairly low force applied, or very intermittent use. Using a stronger material like nylon or higher resolution printing can help. The other problem is dimensional accuracy, which can introduce issues with vibration or binding etc. But the science of 3D printing will only improve.