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Dom Jaeger

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Dom Jaeger last won the day on December 12

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About Dom Jaeger

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    Melbourne, Australia
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    Cinema camera and lens technician

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    http://cinetinker.blogspot.com.au
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  1. Yikes! Be really careful not to damage the mirror.. Normally those lenses fit on an SR, so I agree it must be the PL adapter. First thing I notice is that the bevel on the back of the lens needs to line up with the angle of the mirror, but it looks twisted on your lens. So see if you can re-position the PL mount so that the bevel is exactly between the "wings" of the mount, and when mounted on the camera the bevel is at the bottom. If this basic mistake was made by whoever fitted the adapter, they probably didn't check the back-focus either (meaning how far from the film plane the lens sits). With a fixed focus wide angle like this, the back-focus is quite crucial to make sure the image is in focus, and it doesn't take much to throw the focus out. Usually it's something a technician with a lens projector would need to set up, but you can do a basic check yourself. If you mount the lens (and it clears the mirror) check that objects from about 4 ft to infinity are more or less in focus when the lens is wide open. If you find that focus is noticeably dropping off at the near or far end of that range, the mount will need to be shimmed (or have shims removed). If the bevel is in the right position but the lens still hits the mirror then the back-focus must be really far out and the mount needs a lot of shimming. (Though normally an adapter like that should be machined to position the lens fairly close to where it should be, within 0.10mm at the most.) By the way, if your camera is S16, that lens won't quite cover the format.
  2. I've only worked on a couple of Beaulieu R16s over the years - from that experience and from what people have told me they seem to be OK cameras. I can think of a few reasons Bolexes might be used more though. I think there are many more Bolexes around than R16s, and many more people familiar with servicing Bolexes and access to parts. Like certain other French products, the design is very clever but perhaps not always as reliable or durable as Swiss or German designs. As Greg pointed out, the gate is not as accessible, and the whole interior seems a bit dinky and plastic compared to a Bolex. The custom handgrip battery is a bit of a pain to recell (although admittedly many 16mm cameras have custom on-board batteries). While spring motors only run for a short time per wind and are not very accurate in their speed, the freedom of not having batteries is something of an old-school joy. Almost all the Bolexes I receive for servicing are spring-powered ones. (There are spring-motor Beaulieu R16s too, but they are much rarer than Bolexes). The combination of simplicity (less to go wrong) and yet still packed with features (variable shutter, auto-load, dedicated reverse claw, instant and time-release single frame options, filter slot, etc) makes Bolexes quite attractive to artists and students. The flat base ones in particular are stable and easy to mount, as opposed to the Beaulieu base. High speed C mounts of any flavour tend to be over-priced these days, not just RX ones. You can use normal lenses on a reflex Bolex stopped down to around f/2.8 or beyond without any issues. This old thread talks about some Beaulieu R16 user issues: https://cinematography.com/index.php?/topic/1426-what-are-your-thoughts-on-the-beaulieu-r-16/
  3. Here’s a thread that goes into it a bit: https://cinematography.com/index.php?/topic/39511-bell-and-howell-309/ Here’s a list of the camera’s functions, including what ASA films it can read: https://www.filmkorn.org/super8data/database/cameras_list/cameras_bell/bell_309.htm It’s a Super 8 camera, so it takes Super 8 cartridges. Google “Super 8 film and processing” to find your closest local source and lab. If your student wants to project the film, use reversal. As the description link says, the camera uses 4 AAA batteries for power and a PX13 button cell for the internal light meter. If you google PX13 you can find alternatives like a Wein Cell, or just use a 1.5V button that will slightly alter the exposure reading. If your student wants to learn about metering, they can not worry about the internal meter battery and use an external light meter instead and manually set exposure.
  4. I don’t think you’ll find much to be honest, outside of adding anamorphic adapters or projection lenses which never work terribly well. (As Aapo just wrote..) The only dedicated anamorphics you might find in a compatible mount would be old Arri UltraScopes that came in Arri Standard mount (which usually works with Bayonet mount cameras). 40mm was the widest focal length. These guys in Spain seem to have a set: https://www.camaleonrental.com/gb/ultrascope-set/ They say PL mount, but it may just be an adapter on the original Standard mount. We had a set at the last rental house I worked at, they were a bit funky but fun.
  5. Good question. I'm not sure there is a direct correlation between the colours you see reflected from coatings and the transmitted colour cast of a lens, particularly multi-coated lenses where you might see a variety of colours reflected. Even though each glass element in a lens would have the same multi-coating applied, you often see different colour reflections at different internal surfaces because there is a complex combination of interference cancelling going on. How it all affects the transmitted colours is probably equally complicated. I have a Leica Summilux-C on my bench now for example that has reflections that vary from green to purple to cyan, which if you simply assumed were the colours the coatings reflected, would mean the lens should transmit more warmer colours. Yet Summilux-Cs are usually regarded as being cooler than average. Certainly the coatings are affecting the colour transmission in some way, but we might need someone more qualified than we are to explain it to us!
  6. It’s been a while since I worked on the 16mm Super Speeds, but 10 starts is about right for the 35mm ones. It’s possible there are not that many on yours since the focus travel is less for shorter focal lengths. If you examine the rings you can count the starts. Often a technician will have previously marked the rings, look for little V marks which you’d line up with where the index mark would be before starting to screw them on. You screw on the first double threaded part until the infinity mark a tech made lines up (or the gap you measured before taking it apart is reached), then the guide ring then screw on the rear ring at the mark etc. But yes easy to get mixed up or cross thread etc so I think it would be best to have an experienced technician reassemble it.
  7. Normally you would need to precisely mark each of the helical rings as you remove them to pinpoint which thread start to begin screwing them back into, as each ring has something like 10 different starts. You also need to measure the gaps at infinity so you know how far to screw each ring in. If you don't have those marks, and you're not familiar with working on those lenses, it can be a bit of a Rubiks Cube puzzle to solve, and I would suggest sending it to a professional. Unfortunately it may take even a pro some time to get it right unless there are previous marks to follow.
  8. I'm curious why you'd want to go to so much trouble when there are plenty of cheap projection lenses around that would cover S16? Do you have any experience in lens design? I suspect there are a lot of tolerances involved, not just lens thickness, but also things like diameter, surface, refractive index, centration, wedge, and spacing. You need to think about how to mount optics with curved surfaces, how to secure them and how to measure optical dimensions that you can't measure physically. It could be a fun project if you don't have terribly high expectations. Here's a very basic introduction to tolerances in optical systems: https://wp.optics.arizona.edu/optomech/wp-content/uploads/sites/53/2016/08/10-Specifying-optical-components.pdf But you probably want to read up on lens design a bit if you're serious. I know from servicing lenses that certain elements - ones with strong curvatures for instance - require more care than others. A fast wide angle lens needs much tighter tolerances than a slow normal lens. Edmund Optics have a help line that you could call to get some advice.
  9. These are pretty simple but clearly presented videos outlining some lens basics. The 2nd is by Filmmaker IQ who do a number of these sort of videos. This is a nicely rendered one showing how a Cooke S4 lens works mechanically:
  10. Well, here in Melbourne I think we've had two jobs use the Mini LF so far, no hitches either time. There have been no user issues in the Arri forum or elsewhere that I've heard. I guess make sure your data wrangler is across the Mini LF requirements and has fast enough drives to deal with the extra data. See: https://filmdrives.com/blogs/blog/on-set-with-the-alexa-mini-lf-first-impressions
  11. Well you could say the same thing about historical facts. Would it affect anyone if someone came on the forum and adamantly asserted that Gone With the Wind was shot on Kodachrome, and refused to back down but kept making further claims that you knew to be untrue? No-one's shooting Kodachrome or 3 strip Technicolor anymore, so it makes no practical difference to anyone today. The point is that one forum member in particular keeps injecting falsehoods into the knowledge pool here, and posting authoritatively about things beyond his experience. And when questioned, he simply doubles down and introduces more falsehoods. I don't want to waste my time having these petty arguments (and I'm sure others don't want to either), but I can't see how else to refute this stream of misinformation other than to keep challenging it. But I'm happy to hear other suggestions..
  12. Well I contacted Ben from filmdop and he very kindly responded that while he shoots "a little bit of 65mm", he has his own 5/65mm package, so he hasn't worked with Arri 765s very much. But in terms of them jamming, he very much doubted the Arri 765 is the worst 65mm camera, and in fact he thought it's the opposite, but hadn't worked with them enough to give a definitive answer. I've also emailed the main 765 tech in Europe to hear his thoughts.
  13. .. 🤪 The point about a buckle switch is that if the loop is wrong it tends to trip as soon as you run the camera. A 765 is like a 435, with dual pull down claws and registration pins, once it’s running it won’t lose the loop, so how would it trip a buckle switch “mid take”? And you’re claiming the guy from Arri told you this happens repeatedly? The guy from Arri was telling you his camera is an unreliable piece of junk? This is really the crux of it: you have no experience with these cameras. You’re relaying hearsay and supposed conversations with potentially imaginary people again. You’re drawing conclusions about equipment based on misunderstanding what people may have actually told you, and certainly not on anything you yourself have experienced. Again, please just stick to what you really know, not what someone might have told you once that you then misinterpreted, followed by a string of tall tales to try and justify your mistake.
  14. Well as you’ve found the focal lengths are quite long for smaller formats like S35 or 4/3”, and the apertures quite slow compared to lenses made for those formats, so it doesn’t make a whole lot of sense to go to the trouble of adapting them when there are so many options particularly for S35 PL. Because they use a larger recording area and need less magnification to the viewing format, the resolution also doesn’t need to be as high, so they can seem quite soft compared to lenses made for S35. Having said that, both Duclos and GL Optics have done PL conversions of Mamiya medium format lenses, usually for use on large format cameras rather than S35 ones. I’ve seen a set of the GL Optics ones and they did produce quite lovely images.
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