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Robert Hart

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Everything posted by Robert Hart

  1. Aapo. Regarding a lens for a video split, if your C-Mount camera has a 2/3" sensor, you might be able to use Fujian C-Mount lenses with CS to C-Mount adaptor rings to macrofocus the lenses. The rings are 5mm thick from memory. The Fujian lenses are available as 25mm, 35mm and 50mm focal lengths. I was examining this at one time. My notion was to cut an approxiately 5mm thick piece of aluminium in the shape of the little hatch which closed the hole for the video split, mount it in a 4 jaw chuck on a lathe then machine the thickness down to leave a hollow shoulder to cut a thread onto for the
  2. Aapo. How difficult would it be to design a simple single-speed crystal-controller for the CP16R with the shutter park function. Multiple speeds are nice but maybe not necessary. Offspeed work is easily done on a Bolex. High speed shooting for slow motion is more conveniently doable with digital cinema and at less media storage cost than 16mm film.
  3. If a slug of liquid gas comes out because of shaking the can from habit or turning it upside-down which you should not, shock-cooling of any optical glass the gas hits may crack it.
  4. Appo Lettinen. How is it progressing? Will your final CP16R system be contained within the camera body. I think I saw a post somewhere that suggested you were thinking about a box outside of the camera. A tidier solution might be to take out pre-amp and amplifier board out of the Crystasound amplifier attached on the right of the RA models and put the extra electronics in there.
  5. Ken Hale of Whitehouse Audiovisual remounted in stainless steel, the Angenieux 10-150mm zoom. I have one. With some examples of the lenses, there may be difficulty with interference to the aperture control ring. I bought the PL-Mount from Ken and fitted it myself in Australia. I would not recommend this route unless you have some serious fine mechanical skills for you will ruin something otherwise.
  6. I can't speak for the Vinten 20 but I have had a roam around inside a Vinten 22. The Vintens have some tricky ways of coming apart. Pulling one apart is not for the fainthearted. You are dealing with some fine precision in some parts. The counterbalance spring mechanism can also be damaged if dismantled incorrectly. The friction material is also proprietary and expensive. So far as I know, if you can obtain it at all, it will be in bulk amounts far more than you would need. The fixed "labyrinths" ( my translation is non-adjustable friction modules ) establish an initial level of friction. They
  7. Some otherwise identical lenses of which some are parfocal and some are not may depend on whether they were coillimated for a camera which shot striped film, the stripes being magnetic tracks. There were two tracks, one being the sound recording media and the other a narrow strip called the "balance track" which ensured the film rested flat in the gate. These tracks set the film emulsion very slightly rearwards. Bare film used in a camera with a lens or camera mount collimated for striped film may rest very slightly forward of the image plane of the lens. The image plane of a lens collimated f
  8. Further to above. On viewing the youtube clip, it does seem to be a wavy tape issue as the artifact and the blue dropout are cyclic at about the same rate as the take-up spool rotation partially through a tape roll. Some VHS rental tapes were straight after being put through the slitter but shape memory made the tapes wavy after a few plays. Rolling the tape through the camera at playback speed with the cassette door facing upwards will wind the tape accurately as best as can be achieved. Thermal cycles may help stabilise the shape long enough for a better playback.
  9. There may have been a climatic reason for the random faulty recordings if the tapes were rested partially wound in the camera and stretched slightly in the heat of a car's cabin. With the old reel-to-reel Sony EIAJ half-inch tapes, there was an issue where they would deteriorate, bind to the drum and leave a coffeestain deposit over the transport, clogging the heads. When that happened the friction and the power of the capstan and roller would cause the tape to be stretched and it would no longer play back cleanly. As a desperation measure you could manually ease the tension bar when you could
  10. The second of a two-disk DVD set of "Master and Commander" has a generous and comprehensive set of presentations. The single-disk DVD issued has the topic titles in the disk extras menu but nothing happens if you select any of them. Somebody got it a bit wrong. You need to have the second disk of the two-disk set.
  11. I got locked out again when adding to the response above. Here it is repeated. A good outcome then. I hope I did not send you off on dead-ends with the first few responses. On feeding the film-end through the magazine sprockets when loading in a darkroom or blackbag, with the CP16 mags, I find it helpful to make a single-fold arrowhead about 30mm or 1.5" long instead of cutting an arrowhead on the film. The fold holds the end rigid so the film does not curl under and click into the space on the wrong side of the sprocket. That may not be ideal for the ARRI magazine if the film actual
  12. A good outcome then. I hope I did not send you off on dead-ends with the first few responses.
  13. After managing to get the video larger on the screen and stopping the playback, it looks like that the clutch tension in the centred of the yoke is non-adjustable and there may be adjustment knobs in the centres of the white wheels themselves. The little felt pads on the yoke ends may be light brakes to stop rolls from unwinding or flywheeling the motion when the drive is not going to them. If there are not adjustment knobs then they may be fasteners and adjustment of tension may be by spacers or shims under springs like on tape recorders. It is too hard to know what the system is although if
  14. Once you have adjusted the clutch tension, get hold of a full roll of junk film, load it and run it through to make sure it takes-up firmly all the way to the end but not too tight. You may have to mess around a few times to get it right and it may fall out of adjustment after a few rolls but after re-adjustment should be more stable thererafter. Good luck with it. The ARRI pin-registered transport is as good as it gets. Don't scrimp on getting the cam actuators and little helical gear serviced. If cameras sleep for six months, the lube goes off and needs cleaning then replacing.
  15. I just got locked out again. further to the above. Before you go messing with the clutch tension, check those little felt pads to see if they have become shiny with contamination. If they have, you will feel them squeal under your fingers as you attempt to spin the white nylon wheel. Be very careful not to bed or pull on that yoke or you will ruin it. It will probably ne sufficient to clean them by wetting a piece of paper with isopropyl alcohol and easing the paper back and forth between the pad and the wheel in the same and reverse direction of the rotation. Don't try any adjustments until t
  16. Furthur to the above, I had a look at your video and I think I understand the clutch system. It is similar to that of old tape reel-to-reel tape recorders, old analogue and early pre-servo drive digital video cameras. The amount of pressure upon those little felt brake pads which push against the nylon wheels appears to be determined by a common clutch on the rocking yoke. There appears to be a diaphragm spring with spokes at the pivot point of that rocking yoke. It is too hard for me to see in your video on my computer but my bet is on there being an adjustment screw in the centre of that
  17. Something went pearshaped when editing the previous response so here is another try. The ARRI is very likely different however in loading your magazines, it is possible for the film to pass on the wrong side of an outfeeding roller. This can happen with a CP16 magazine's light trap roller. The CP16 camera will tolerate it but also may scratch the film. I observed that you were dragging on the film to action the camera motion. You will damage the film as the gearing becomes an increase drive. It is a reduction drive when powered by the camera motor. If the film is walking off the
  18. The ARRI is very likely different however in loading your magazines, it is possible for the film to pass on the wrong side of an outfeeding roller. This can happen with a CP16 magazine's light trap roller. The CP16 camera will tolerate it but also may scratch the film.
  19. For going the other way, the 81EF filter is a less aggressive colour correction for using tungsten-balanced stock in daylight. In early evening, using this filter with tungsten-balanced film confers a sweet look to the evening sky as background.
  20. Choosing a film of the wrong colour temperature will not help in regard to visual effects. You are really only changing the hue of the recovered image. Your visual effects will be better achieved by lighting and production design. Before you go burning off a bunch of expensive film, maybe do some tests with a digital stills camera with varying colour temperature settings. If you are stuck with daylight film already, buy or hire an 80A colour correction filter to fit to your camera lens or slide into a mattebox. You may lose two stops of light. You could put blue gel over your tungsten lights b
  21. Surface coating films can cause difficulties. At a cinema in a remote town, I received a 35mm print of "Rocking Horse Winners". As a second-tier cinema we received the prints after they had done their time in the city cinemas. The print looked good with no scratches or signature scuffmarks of being fed off a platter system but went only through part of the first reel before it began to bind in the gate. Whatever was used to rehabiitate the print was coming off, cooking onto the gate and pressure plate and frying on hard and sticky. It was so bad that it stripped the holes then bent the pulldow
  22. I see nothing wrong with doing this but I am also an unqualified mug. Once you establish with tests that the results are good, it will save you having to scramble around with the handheld meter.
  23. He using fancy words which is what people do on lecture circuits and events. The work to change a good script into film must also be good or the audience will not enjoy what it sees and hears.
  24. For what it is worth, in this clip there are 8mm, 9.5mm, 12mm, 16mm, 25mm, 50mm, Optar Illuminas, 20mm, 35mm, 85mm Optika Elites. It is not a proper technical test. There are more accomplished folk who can do that far better than myself. The camera was a SI2K. The lens apertures were set at T4, close to their sweet spot of around T2.8 if my geriatric memory serves. The image seems to be consistent across the two types which are descendants of Lomo lens designs. A DoP friend prefers the look and clarity of CP ULTRA T* primes by Kowa. They seem to be warmer than the Optar/Optika lenses and yield
  25. Charles. Thank you for the information and link.
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