Dom Jaeger

Hi Karl, by DR8 do you mean double run 8? What's the camera? Do you not know the shutter speed?

In their day the Zeiss Super Speeds were top of the line and used on countless features, TVCs, docos etc, but lens design has come a long way in 30 years. The modern Zeiss cine lenses are cooler, sharper, less prone to flare, breath less and have higher contrast, especially at wider apertures. But that's a comparison with some of the best lenses currently on the planet.. As with anything to do with art, what's 'good' is often subjective. Some people prefer the look of older lenses to newer ones, sometimes it suits the mood required. Ultra Primes are actually slower, if speed is a requirement. As far as build quality goes, the newer lenses are probably more robust, and heavier (especially Master Primes) but just as accurate in their scaling. Given the age of Super Speeds though, there can be quite a difference lens to lens. Coating damage or element scratches, thread wear, shiny iris blades etc can impact on an individual lens's performance. Also certain lenses, such as the 12mm, were never that great to begin with. The T* marked lenses had what was then a newly developed technology: multi-coated elements that reduced flare and increased contrast, speed and colour fidelity. Much like the stars on detergent packets that say "new and improved". Not sure about the 26.. serial no lens. East German Zeiss lenses were always branded Zeiss Jena as far as I'm aware. It might be an old lens that was rehoused?

During the software upgrade I believe each mag needs to be fitted to the camera. It sounds like this mag may have been missed. The upgrade needs to be redone with that mag attached. Our LT and mags had already been upgraded when we received them, so I haven't done this personally. I'm just recalling what I read about the software upgrade procedure. Best to call Arri and be properly informed.

To completely isolate the zoom elements from the front and rear groups you would tape the zoom at the wide end and the focus at minimum. But the reverse is generally safe too (ie zoom at long end, focus at infinity), the benefit being the heavy focus group is fully engaged in the threads. I'd avoid shipping with the zoom at the wide end and focus at infinity, since the front element of the zoom group and rear element of the focus group are very close in that combination. Also avoid leaving either zoom or focus somewhere in the middle of their range, as a knock could cause a bump in the travel mechanisms.

Thanks for taking the time to find that out, Jean-Louis. Very interesting.

Hi Jean-Louis, I thought that might be the case, but then how do you know when the aperture limitation kicks in? Does the maximum aperture slowly move from f2 to f2.8 through the focal range, or does it only begin as you approach telephoto? I imagine it's a condition of the lens having a long (15 x) zoom range, so maybe only the very long end is affected?

You can remove the viewing screen by loosening the 2 screws that hold the retainer and sliding the retainer up. Using a piece of masking tape you can then hold the bottom of the screen and slide it out. On earlier models there was a spring clip instead of a retainer, which could be unlatched on the right side and swung clockwise out of the way. The screen can be cleaned with alcohol and a cotton swab. I'm not sure if you'll find one without the TV safe markings. The front barrel on Angenieux zooms often stated the maximum geometric aperture (f-stop), while the iris ring was marked in photometric stops (T). So the 10-150 is T2.3 but f2. I don't know why it reads 2 - 2.8 though.

Buster Keaton's The General. A masterpiece of the silent era, and after 85 years still more entertaining than just about every modern blockbuster.

Unlike a film camera, which can be mechanically checked very precisely with a depth gauge, digital cameras need to be checked optically. A collimator or chart test (or diagonal newspaper test) are some of the methods available to check flange depth, but they all rely on the lens used being spot on. You can do multiple checks with different lenses, or check the test lens on a collimator first, but the simplest way is to use what Arri themselves use, a Denz Flange Depth Controller (FDC). It's basically a mini collimator housed in a lens, which gets fitted to the camera mount. The camera is connected to a monitor, and by adjusting the FDC barrel a simple bar graphic shows exactly when the flange depth is correct. A scale on the FDC barrel then tells you how many hundredths of a mm you need to add or remove from the mount shimming. Very simple and portable. I believe other companies now also make versions of the same idea. Because of the robust build quality and design of Arri cameras generally, once the flange depth is set it rarely needs adjustment. But it's one of the checks a rental house does regularly.

If you've got a reflex model, don't forget you need to compensate for light loss in the beam splitting prism. If you move the turret out of the way (or remove the taking lens) you can see it behind the filter holder. The prism sits between the lens and the film plane and diverts about 1/4 of the light to the viewfinder, allowing you to see through the lens even when filming. The first reflexes still had the 144 degree shutter angle, giving about 1/60 sec exposure time at 24 fps as you calculated, but taking into account the prism light loss the 'adapted' exposure time is about 1/75 sec, not far off the 1/80 sec 'adapted' exposure time of later reflex models. If you look through the archives of cinematography.com in the Bolex forum you'll find plenty of discussions about how people work out their exposures for reflex Bolexes. Some use the 'adapted' exposure time, some prefer to offset the ISO setting on their meter, others just open the lens 2/3 of a stop more than their meter indicates (using a meter with frame rates and an assumed shutter angle of 180 degrees). None of this explains your problem though. Given that you calculated for 1/48 sec exposure time, your footage should be about 2/3 of a stop underexposed, not over. Even if your camera was running extremely slow, say 18 fps when the speed dial indicated 24, the footage would still not be overexposed. Did you check the iris of the lens as Bernie suggested? Or your meter? Could you have made a mistake with the film stock speed?

The exposure time varies depending on what kind of H16 Bolex you have. On early cameras (below serial no 100401) the shutter angle is 192 degrees, so at 24fps the exposure time will be 1/45 sec. Later non-reflex cameras have a shutter angle of 144 degrees, giving an exposure time of 1/60 sec at 24 fps. The reflex models (except the EBM and EL) have a shutter angle of 133 degrees, but also lose about a quarter of the light due to the prism, so the 'adapted' exposure time (taking into account the prism loss) is 1/80 sec at 24fps. If your footage is overexposed, it sounds like you may have an early model with a 192 degree shutter, although the difference between 1/48 sec (which you say you calculated) and 1/45 sec should be negligible. The later cameras would actually give you underexposed footage if you measured for a 180 degree shutter. The most likely explanation is that your camera is running slow, and giving you longer exposure times than you are calculating for. Have you used the camera with other lenses?

It's a little hard to see exactly, but the claw looks a bit odd. I'm wondering if perhaps the front plate was removed at some point and the two claws (forward and reverse) were mixed up and positioned incorrectly when the front was refitted. Looking from above with the turret forward, the longer claw should be to the left and the smaller reverse claw to the right. They both attach at the same pivot. With a very small screwdriver you can undo the two screws holding the plate that covers the claw pivot, remove the plate and have a closer look.

I guess the Mutar expands the image circle well beyond what the lens was designed for, and anything outside the 16mm diameter limit doesn't intersect at the iris. It's interesting that the image still projects sharply to the edges even over that limit when the iris is opened up. Maybe an optical engineer could explain it! Yes, same one. I don't know. It's the only one I'm aware of. Your lens is actually an Arri bayonet mount, different to Arri STD (Standard) mount, which was an earlier design. Standard mount lenses will fit in a bayonet mount camera but not the reverse.

It can't hurt to call up some rental houses that deal in film gear and ask if you can come in and familiarise yourself with the equipment. All the rental houses I've worked for have always been happy to let assistants do that, especially if you've already read all the handbooks. After all, it's in their interests that the people using their gear are familiar with it.

When used with the Mutar 2X the image circle of the 10 - 100 (20 - 200) is actually limited by the iris. As you stop down the coverage decreases, from about a 22mm diameter wide open to about 16mm at T16. So you could theoretically use it on a 4/3 sensor camera if you only shoot at T2!

Hi Patrick, sorry, I didn't notice that plate attachment, but you're right - it looks to be something designed to attach rods, much like an LWS but with a twist lock instead of a shoe. I asked a few people who might know but none of them had come across that design. It might have been a custom job as you said.

I've tested a Zeiss T2 10-100 with a Mutar 2X on projection and it covers Super 16. The Mutar I tested was a bayonet mount version, but the optics are identical to the later PL mount model, which is compatible with both the 10-100 and the Super 16 converted 11-110. There may have been an even earlier bayonet version that masked the image circle as Mitch describes, but I'm not aware of it. The coverage of zooms is smallest at the wide end (and at close focus). The 10 - 100 covers a Super 16 image circle at focal lengths of above about 32mm (and as low as 25mm at distances of 15 ft or more). So using the Mutar would be helpful for the 20 - 32mm range.

The only real difference is the shutter angle - the half moon is 170 deg, most bow ties are 156 deg, unless it's an early version which is 144 deg. So at 24 fps your exposure would be around 1/51 sec with the half moon compared to 1/55 or 1/60 with the bow tie. The biggest concern is probably that the bow tie design was notorious for smearing highlights under certain lighting conditions.

There were lenses made for both formats in standard mount. Those designed for 16mm won't cover a 35mm frame. With Cookes for example, it's fairly easy to distinguish them - Kinotels were for 16mm, Speed Panchros for 35mm. Zeiss lenses are a bit trickier - generally you need to go by the focal length/aperture, and know which ones are which. The 16mm lenses tend to stick out further at the back, and obviously go to wider focal lengths. There's a comprehensive list of Zeiss cine lenses here: http://cinematechnic.com/resources/zeiss_cinematography_lens.html A quick test to determine what format a lens is designed for is to hold the lens facing towards a bright light source that also contains some contrast pattern (a window with open blinds works well) and hold a piece of white paper 2 inches behind the lens mount seat (or just play with it until a sharp image forms). If the image circle has a diameter that would cover a 35mm frame, it's a 35mm format lens.

Hi Patrick, as far as I'm aware there was never anything officially made to attach rods to a 2C flat base. Arri made a sort of shoe base for the 2C that extended out the front with a moveable lens support for use with heavy zooms, but nothing that fitted a flat base. A very knowledgeable ex-cameraman who worked extensively with 2Cs told me that back in the day he had adapter plates made up to allow a 16mm bridge plate to be fitted to his flat base. A machine shop could easily whip one up if you could work out the required dimensions.

Yes I'm a rental house technician here in Melbourne. I know, pedantic and annoying, and living in an ivory tower.. :D I guess I'm applying rental house standards, where the lenses are constantly being checked, and assistants (hopefully) do tests before a shoot to catch any problems. A technician can then fine tune the back focus of a lens in-house if necessary. It always sounded arse-backwards to me when I heard stories of crews adjusting a RED mount to a particular lens, then having to set it back again afterwards. But I can understand it's a handy feature sometimes, especially for owner-operators, as David pointed out. And if it works, it works. Good job on Offspring, by the way. It was probably the best home-grown drama of 2010, IMHO. My only complaint is that the pub location was the Union Hotel, and every time I went to drop in there last year it was closed because you buggers were there filming. Now I hear there's a second season. I'm all for Australian content on our TV screens, but does it have to be my local? :P

I have to respectfully disagree on this. If you follow some very simple guidelines - avoid damaged or dirty shims, line up the screw holes and do up the mounting screws with even tightness in opposing pairs - shimming is 100% foolproof. Takes me about 5 minutes and I've never had a problem. I imagine that's why shims are used to adjust the back focus on every high end modern cine lens and the flange depth on virtually every professional cine camera (including Alexa). Having said all that, Moviecams and Arricams do have the facility for technicians to fine tune the flange depth by one or two hundredths of a mm using a hex key adjustment that moves the entire inner skeleton relative to the mount, but anything outside this limit (effectively twice the allowable flange depth tolerance) requires a shim change. This is primarily because the gate flatness (and position) can't be maintained if the skeleton is moved more than this. If the Epic engineers were sensible that's how they've designed their camera - shim the mount to within tolerance, then allow a tiny adjustment to compensate for minute variations in lens back focus. Really, any professional cine lens that is out by more than a few hundredths of a mm (an imperial thou or two) probably has more issues than just back focus and shouldn't be used until a technician has checked it over. That kind of error usually means it's been dropped, damaged in transit or has a loose element.

P+S Technik have just put their entire stock of Arri 35mm spare parts up for sale. Apparently, due to the "digital wave", they will no longer be repairing or upgrading film cameras, but focusing instead on "providing innovative digital cameras for the Digital Cinematography market". The only film service they will continue to provide is 3-perf conversions. I'd contact them ASAP to find out if they might do a last BL conversion for you. Otherwise try Gekko-Cam in Munich.

Right, so it's a mechanical adjustment. Sorry, from your description of a clever new 'device' I imagined something electronic. Still seems a bit risky though. As you observed with the Aatons, ground glass adjustments tend to be made once and then left alone. 35mm Arri cameras have several set screws to adjust the depth, flatness and position of the ground glass, and it certainly isn't a procedure I'd want to do in the field. With something the size of a 5K sensor I would think the adjustment would need to be even more critical, notwithstanding the fact that a ground glass image isn't what's actually being recorded. I'm not directing this at you John, just throwing it out there, but I guess my query is: why the need for an operator-adjustable flange depth in a professional camera? Shouldn't professionals be using properly collimated lenses? And if the flange depth does require adjustment, why move the sensor and possibly introduce alignment issues when it's much safer to just re-shim the mount?

Thanks for sharing your research, Jorge. One thing I thought I'd mention though - I wouldn't recommend removing the mask from inside the camera mount as you have done. The mask helps to prevent light that falls outside the gate aperture from reflecting off shiny surfaces and fogging the film. This is especially prone to happen when using a 16mm format lens which has a much larger image circle than a Super 8 lens.