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Dom Jaeger

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    Melbourne, Australia
  • Specialties
    Cinema camera and lens technician

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    http://cinetinker.blogspot.com.au
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  1. Ha, that depends entirely on the lens in question! For most of the lenses I work on as a cine lens tech I need a test projector and autocollimator to check and adjust them before and after re-assembly. It’s very easy to introduce decentration or tilt aberrations that may not be immediately apparent to a lens owner who may just feel that the lens isn’t quite as sharp as it used to be. Just one example: if you remove the front element of a Zeiss Ultra Prime, you will have lost the finely calibrated element centration and introduced off-axis flare and uneven field sharpness. It will still form an image, just a sub-par one. A technician will need to perfectly recentre the element while projecting it on a test projector. Many modern cine lenses have adjustments like this - sometimes in the front, sometimes the back, sometimes a floating group, sometimes even the rotational position of each element is critical - so be very careful attempting to clean inside lenses like this, even if it seems as simple as undoing a lock ring or removing a few screws. Obviously cheaper, mass produced stills lenses or older lenses tend to have fewer (if any) adjustments, and the elements usually go back together just fine within their pre-centred housings, but I’d still be careful with anything very fast or very wide.
  2. Hi Jon, The Scoopic has an auto-iris which works by way of a light meter cell just above the lens connected to a servo motor that controls the zoom iris. It’s a proper multi-bladed (6 or 8 blades from memory) iris, but the zoom is fixed. The EL has a light meter cell that can be dropped behind the lens for proper TTL metering, but it has to be moved out of the way before filming can begin, so you can’t meter while filming. It works with any lens you mount to the camera. Two LEDs in the viewfinder tell you when the aperture is correctly set. With this and other Bolexes it’s also possible to use an auto-iris zoom like the various EE or OE models which do meter and automatically adjust the aperture while filming, but the iris is 2 leaf diamond-shaped. You could contact Du-All or Visual Products in the States to ask their opinion about the servicing issues of each (though I’m not actually sure if they work on ELs). I’ve started working on Scoopics, even though they are a bit of a pain - I have three in my shop at the moment - but every camera has it’s own quirks and I’m far from a Scoopic expert. I don’t work on ELs though, they are not easy to work on and I have more than enough Bolex work with all the other models.
  3. I’ll be curious to hear any responses to this question. As far as I knew, there was only the 24mm Standard Speed, made for 35mm format, and the 25mm Super Speed made for 16mm format. Those are both Distagons, the retro-focus design family Zeiss often uses for wide angle lenses. The only reference to a Zeiss 25mm T2.2 in Standard mount I can find with a quick google is a seller with examples of a 25mm Planar lens, which was a design typically used for medium to long focal lengths. The widest Standard Speed Planar for example is 32mm, while the widest Super Speed Planar (for both 16 and 35mm formats) is 50mm. So a 25mm Planar is unusual, and in fact the same seller has a 16mm Planar in Arri S mount as well, which is extremely unusual. Going off that I would take a punt that these are very early 16mm format lenses, but they don’t appear on lens lists for the Arri 16St, which is odd. At any rate, if they are 16mm format lenses it’s very unlikely they would cover 35mm let alone S35.
  4. The camera in question is a 35IIIC, the 1982 evolution of the 35IIC, not a 35III. I don't imagine they changed the motor interface when Arri came out with the IIIC, so it seems likely to me that a 2C flat base might be compatible, but since I've never had a IIIC in front of me I don't actually know. You could try to send a personal message to Jorge Diaz-Amador, who is a technician familiar with IIICs, or Satsuki Murashige who owns one, both of whom have posted here. See this thread for example: https://cinematography.com/index.php?/forums/topic/71382-arriflex-cameras/page/2/&tab=comments#comment-525759 Or someone else familiar with them may chime in.
  5. http://www.davidelkins.com/download/download_files/arri/technical_info/ramp_tutorial.pdf https://www.cinematography.net/edited-pages/Ramp-Shots.htm Arri 416 can also do ramping using something like an RCU-1 or WRC-1, see the manual: http://www.davidelkins.com/cam/manuals/manual_files/arri/416_manual.pdf No 16mm camera can do controlled internal ramping as far as I know, you always need an external controller. No shutter angle compensation either, only iris. You can always use older cameras with analogue speed governors (not electronic steps) like a Bolex or something and manually adjust the speed dial while opening the lens up, but that requires planning and skill and probably an extra pair of hands!
  6. If rubber tools using friction won’t work, the simplest, non-damaging thing is to just drill two small holes in the flat surface on opposite sides and then use a lens spanner wrench, which you can buy on eBay for as little as $10. I’ve done this dozens of times to remove difficult lens lock rings and other things. It will undo the ring and leave the threads undamaged if you ever need to use it.
  7. Try a rubber grip of some sort - I have a variety of tools to remove lens lock rings most of which I’ve made myself. You can start with rubber dishwashing gloves, or a bath plug, or something like that. I have made some tools using a cylinder with O ring rubber glued to the end. You can put a drop or two of oil in the step up ring threads to help free it. Last resort might be to drill a couple of small holes in the ring and use a lens wrench.
  8. I could be wrong, but I think the phenomenon is called "Shane Hurlbut talking out of his arse". I guess you could say that increased resolution might make small out of focus highlight shapes more visible, but other than that I can't think of any reason why the recording medium would affect the shape of a lens attribute. At 9.40 he talks about a T1.5 Canon lens compared to a T1.9 Xeen as being "four tenths difference", which tells me all I need to know about Shane Hurlbut's grasp of optical science. (For those new to aperture stop calculations, stops are not a decimal scale. T1.5 to T1.9 is not "four tenths" but 2/3 of a stop difference. T1.4 to T2 is not "six tenths" different, but a whole stop. Further down the scale, T4 to T5.6 is not "sixteen tenths" difference but also a whole stop. It kind of shocks me that Hurlbut doesn't actually know this, and is teaching people. Or perhaps he knows perfectly well, but he's just a shill trying to minimise the difference for marketing purposes.)
  9. There was a thread not long ago about the difference between Switars and Macro-Switars, not that it shed much light: https://cinematography.com/index.php?/forums/topic/82538-kern-switar-vs-kern-macro-switar/ But if you want to see a Switar in action, Uli just posted a lovely test he shot with one: https://cinematography.com/index.php?/forums/topic/85940-ultra-16mm/&do=findComment&comment=551076 I mean, there’s very little to complain about in terms of how good a little C mount lens can look. They get a bit misty wide open, but not many lenses from 50 or 60 years ago don’t do that at f/1.4. The Macro-Switar pre-set version is a later lens, with better coatings, a slightly improved and faster design and much closer focus capabilities, but it’s not several times better, which is how much more it costs these days. In fact you can sometimes pick up a Switar for fairly cheap if you’re patient, but the pre-set Kerns seem to always be over-priced. So personally, unless money is no object or you’re definitely into macro work I don’t think it’s worth it really. Obviously the condition of the lens matters too, and there are some beat up looking Switars around, but choose wisely and I think you’d be fine with a Switar.
  10. Exactly. The gate is beyond the viewfinder light path. That’s a hair on the groundglass or in the viewfinder, it won’t show up on the film.
  11. It's about a third of a stop light loss. The lenses are in f stops though, so maybe open a half stop more? Nice exposures for just guessing!
  12. Looks great Uli! A Bolex can definitely be made to be very stable, if you send it to an experienced technician to service. The unstabilized footage will tell us what might need addressing - whether the unsteadiness was more lateral (side rail spring) or vertical (claw, pressure plate). So a non-reflex H16 with matching non-reflex Switar (AR on the front not RX)? What stops were you shooting at?
  13. You might want to read the Arricam manual to get an idea of how the aperture plate works. There is no S35 gate as such, there are 3 perf and 4 perf aperture plates. The aperture plate can be fitted with a variety of masks with different aspect ratios and formats, but usually people leave the full aperture mask in to record the full negative. This allows for some reframing or multiple aspect ratios in the finished product. The full aperture mask is usually either the Universal or ANSI 1.33 “silent aperture” mask. The operator frames using a chosen ground glass marked with a particular aspect ratio (or a combo of several) which is extracted from the full negative in post. Here’s the Arri ground glass and format mask book: https://www.fdtimes.com/pdfs/howtos/ARRI_Groundglass_and_format_guide.pdf If you shoot with the silent 1.33 mask in the aperture plate, the negative scan will be like the pictures you posted. You’d want the corresponding ground glass to be able to frame it properly. But essentially you can extract any aspect ratio from this image in post by cropping it down, and usually you’d always crop in a little from the edges of the actual exposed area, where you might see small hairs or fuzz etc. The ground glass marks are always smaller than the actual aperture for this reason.
  14. The gap for the filter holder is a small slot that leads to the front surface of the prism. It can only allow a bit of light to possibly bounce around and hit the frame of film being exposed in the gate, but if the shutter is closed it shouldn't fog anything. So if you only remove the filter between takes you should be fine.
  15. Advice from CMLs Geoff Boyle: Notes on getting into (and surviving) the moving picture business
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