Dom Jaeger

52.00mm is the nominal flange depth of all Arriflex cameras, meaning the distance from mount flange to film plane. It’s the same distance for Arri Standard, Arri Bayonet and Arri PL mount. So every PL mount lens is (or should be) set so that the lens forms an image when focussed at infinity 52.00mm behind the lens mount flange. The amount a lens protrudes past the mount flange (ie the rear element and associated housing) is a different thing to the flange depth. It varies and depends on the individual lens design. As a general rule wide angles protrude back further than longer focal lengths, and telephotos tend to not protrude back at all. Almost all lenses made in PL conform to the film era standard that limits the protrusion to a certain depth and diameter, to avoid hitting a spinning mirror, or a sensor OLPF. Be aware that some lenses (particularly vintage) shift the entire optical block as you focus, so the rear protrusion can vary depending on where you’re focussed. It is always the furthest back at infinity. Lenses made for other systems, like 16mm C mount or stills cameras or mirrorless digital cameras, will be designed for different flange depths, and are often incompatible with PL mount movie cameras because the flange depth is much shorter, so the lens would need to sit well inside the PL mount to function properly.

Adapted lenses will generally be fine, just watch out for certain early Arri Standard mount lenses by Cooke (Kinetals) or Schneider which may protrude too far back. They don’t work on cameras like an Arri SR, so may foul on a K3 too.

All PL mount lenses have the same nominal flange depth - 52.00mm, regardless of whether they are made to cover full frame, 35mm or 16mm. Beyond that, the main factor to consider is the protrusion past the mount flange, and whether it goes too far to clear a spinning mirror. But the rule tends to be that you can use larger format lenses on smaller format cameras (ie 35mm lenses on a 16mm camera) but avoid using smaller format lenses on larger format cameras (ie 16mm lenses on 35mm cameras). So in your case, the vast majority of PL mount lenses should work.

No. You just need to look at the dimensions, a PL or EF/FD lens simply won’t fit in a Standard mount. EF and in fact most stills mounts have much shorter flange depths as well, meaning they would need to sit well inside the Standard mount.

Forum member Greg Irwin was 1st AC on this film, so hopefully he chimes in to give a more accurate answer, but I would assume the C series were expanded for use on the Alexa 65 (perhaps one of the first instances of this, now it’s quite common). I believe this was filmed before the release of the Alexa LF, so the 65 was often the camera of choice if filmmakers wanted more resolution. The sphericals mentioned - Primo 70s - don’t actually cover a full Alexa 65 sensor (despite the name), so they would have punched in a bit. Probably also punched in when using the anamorphics. But they certainly got more resolution than if they’d used an Alexa XT.

Actually quite a few anamorphic designs use anamorphic cylinders set at 90 degrees to control the squeeze, or attempt to minimise anamorphic breathing. The system used in Panavision anamorphics to control mumping (the variation in squeeze that happens as you go to close focus) is essentially two counter rotating anamorphic elements, of very low power, that reduce their combined squeeze the closer they rotate to 90 degrees, at which point they cancel each other out. There is also an anamorphic front attachment that mimics the horizontal anamorphic flare but without introducing a squeeze which uses the same principle. Putting a rear anamorphic adapter at 90 degrees on an anamorphic lens would indeed cancel the squeeze, while keeping the flare behaviour and some of the optical falloff of the anamorphic. But you would lose a lot of light and degrade the image, since those rear adapters always do that a bit. They work like a doubler, but only in the vertical axis (when normally fitted). So you would also end up with a cropped image, since the adapter magnifies, then crops that axis.

In theory anyone with a soldering iron can make them - you just need to source the 11 pin Fischer male plug and a switch. But you are in Munich, so there are probably twenty retired Arri technicians living in your neighbourhood. :) Maybe ask Arri for a local cable tech, or ask one of the local rental houses, or Gecko-Cam or Pure-4-C.

I’m not quite sure what the issue is .. you talk about misaligned scale markings but also working on the aperture? … but if you don’t have experience working on these lenses, send them to a technician that does. These are expensive and complex assemblies, and you can easily create more problems than the one you are trying to solve. Leitz does basic training courses on them if your technician needs to learn more.

It doesn’t really matter if you shot 3 perf or 4 perf or S35, all you want to do is match the aspect ratio you framed for earlier, which is 1.78. So you just need a 1.78 ground glass for the 2C, or have a rental house technician pencil in a 1.78 frame line. It’s very similar to a 1.85 frame line, which is more likely to be found in a 2C ground glass, so you could just use that with the awareness that the 1.78 frame is a smidge taller or a smidge less wide, depending on how you crop the image in post.

It might take a screw-in cap, but not necessarily be a standard filter thread size. If you have calipers and a thread pitch gauge you can measure the cap thread (rather than the lens thread). Usually the thread will measure a few tenths of a mm under the nominal size. Or take it to a shop that has those tools - a fastener supplier or lens repairer for instance.

Is the front thread for a filter, or is it the thread for the front optic retaining ring? Not every lens has a filter thread.

I've looked into it. I think it was simply laser cleaning of the textured surface, but it requires some testing and calibration, and being open to potentially damaging a test subject. Also different ground glasses (some are made from fibre glass bundles) might need different settings. I have too many other pokers in the fire at the moment to wander down that rabbit hole. I sometimes wonder what happened to Bernie's workshop and tools, someone must have bought/inherited them. It would have been a treasure trove for camera techs.

The turret lock would help to prevent focus issues and possible deformation of the turret plate, but it has nothing to do with the light leak. The leak is an intense, narrow line, so it’s caused by a small hole somewhere adjacent to where the film travels. You need to check the camera front for missing screws. Light leaking through other areas, like the filter slot, viewfinder or bloop lamp channel, tend to cause more diffuse leaks that fog the film rather than causing this sort of narrow line.

I second what Simon is saying. The first image just looks like edge fog from loading or somehow flashing the edge of he film. The second looks like a hole letting in light, maybe a screw missing in the turret plate or the screw for the top shoe. Carefully check the area around the gate for holes. The intensity of the leak would vary depending on where the sun is shining. This is why getting a camera serviced and checked before an important shoot is very wise. A little outlay beforehand can prevent an entire shoot that can't be easily re-shot from being ruined. Later turret models (I think Rex2 and after) were fitted with a turret lock at the top right, which helped prevent heavy zooms from flexing the turret away or bending it. You should also have a bottom port turret locking cap, though this is not effective in preventing the turret from deforming.

An iris never vignettes into the coverage the lens was designed for, but if you project a lens so that you can see the full image circle, stopping down the iris sometimes reduces the circle diameter. So in these cases the iris is creating the limit of the image circle. I’ve seen it many, many times. In my work we often deal with S35 lenses being used on full frame sensor cameras, and working out the useable coverage is a common task. Some lenses will cover a larger format if they are not stopped down past a certain stop.

Hi Greg, I don’t think there’s a matte, it’s just the limit of the lens image circle. The only way to expand it would be to add a focal length extender to the rear, which would change the focal range. Different parts of a lens can be the limit of the image circle, sometimes it’s the iris, sometimes it’s the rear element or another optic. In a zoom it can change as you adjust focus distance or focal length. On some zooms there can be a rectangular front element matte that limits the image circle, but that’s not the case with this zoom.

Good to know it’s just the mount was set to N16. The unit at the back is a Chrosziel drag module, they were sometimes fitted to Angenieux zooms to allow a slow, smooth zoom. Turning the knurled ring should adjust the friction for the zoom.

Well the most obvious issue is that the vignette is off-centre, which means the camera mount has not been properly recentred for S16. Perhaps check with whoever did the conversion. On many Arriflexes you can rotate the PL mount between Super and Standard, so hopefully they just forgot to set it to Super. Otherwise, that lens is definitely not a S16 zoom, none of that era of Angenieux zooms covers S16 if the wide end goes wider than 15mm. So whoever sold it to you was being misleading. I can’t remember exactly, but I think it vignettes almost up to around 50mm.

Looks like light is being reflected from the side of the adapter, causing veiling glare over the whole image except for where the edge of the gate blocks it. Look for shiny surfaces inside the adapter and maybe paint it matte black or line it with velvet or felt.

So the curved scratch is identical in every frame? Does it move or change shape? It’s hard to diagnose anything from a single frame. Generally camera scratches are very repetitive, due the nature of the machine. They are normally vertical, since that’s the only direction the film moves. The only exception might be where the film bends and twists between sprocket rollers and pressure plate, but the mags are designed to only touch the edges of the film even if the loop slips and film hits the mag wall. Cinch marks from tightening a dirty roll will be random, and not limited to the frame, so it’s not that if this is repetitive. If you’re certain it came from the one mag, it might be worth removing the mag pressure plate assembly (2 screws) and checking the film path inside for film chips or something. You could also do a quick scratch test by running a few feet of clean film through and examining it.

Here's a frame from the earliest known 70mm film, a short by Birt Acres from 1897 called "Henley Regatta".

Ten 765 cameras were completed by the project end in 1988, whether they are all still working I don't know.

https://cinemagear.com/details/mitchell-fc8.html

No way are Angenieux Optimos (released post circa 2000) available in Arri Standard mount, nor some others here. Where did you get this list?

No, the original 2C came with three Standard mounts and was released before the Bayonet mount. The first 35mm Bayonet mount camera was the 35BL released in 1972, 8 years after the 2C. Around this time Arri began marketing the 2C/B with 2 Standard mounts and one steel Bayonet mount, specifically for heavy zooms, because flange depth accuracy is much more crucial for zooms. Older 2Cs could be retro-fitted with a 2C/B turret. Here's a 2C/B brochure: https://www.pacificrimcamera.com/rl/01045/01045.pdf Looking at old Arri price lists the only 35mm zooms available from Arri in Standard mount in those days were these ones: Angenieux 25-250 T3.9 Angenieux 35-140 T3.9 Angenieux 20-100 T3.0 See: https://www.pacificrimcamera.com/rl/01384/01384.pdf You can also find a few older 35mm zooms by Som Berthiot in Standard mount, though they are rarer and not as good. I think also the Zoomar 36-82 came in Arri Standard. Generally from this era nothing that goes wider than 20mm is a 35mm zoom, it will be for 16mm. Because Standard mount really wasn't a good option for zooms, most zooms made after this were sold primarily in Bayonet mount, then PL mount. Some of the older zooms by Angenieux and Cooke used a universal mount that could then be fitted with a variety of other mounts, so you might find something like a Cooke 20-100 or 25-250 that could theoretically be fitted with a Standard mount, but they really are too heavy. Apart from maybe the Angenieux 35-140 most 35mm zooms need to be supported (especially if they are in Standard mount), which is tricky on a 2C. There was a special zoom support base made for them, but they are hard to find.