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dan kessler

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Everything posted by dan kessler

  1. read about it here http://www.film-tech.com/ubb/f14/t000220.html so is this the total abandonment of 15/70 by Imax?
  2. I think Pav Deep was alluding to both. Main point being, with such demand remaining in the world for film, it's like Mark Twain once said -- Reports of his death are greatly exaggerated.
  3. Well, this took me about 2 minutes to find: http://en.wikipedia.org/wiki/Film_industry India is largest producer of films in the world.[1][2] In 2009, India produced a total of 2961 films on celluloid, that include a staggering figure of 1288 feature films More recent stats found here: http://cbfcindia.gov.in/html/uniquepage.aspx?unique_page_id=30
  4. That's assuming that there's not something else going on in the camera itself. You said the previous owner had it serviced... you sure everything's okay?
  5. First thought is overloading due to binding, misalignment, or underpowered motor. I'm getting real suspicious about this motor.
  6. Well, there's the Unilux strobe system, which is routinely used at high frame rates for nice, crispy slo-mo splashes, crashes, etc. Very common in TV commercials. Of course, the flash rate is fully synched with the camera shutter, so the lighting appears continuous. For a party strobe effect, you don't want that perfect sync, obviously, but then again, a random flash rate is going to be hit-and-miss with the shutter timing. Surely it will work, just don't know if you can be too picky about controlling it. Sounds like something you really should test beforehand. Exposure? What about using a light meter designed for flash?
  7. These financial articles never seem to mention Kodak's motion picture operation, which, according to some here, has always been profitable. Like everyone, I wonder where those pieces of the company will end up if there is a bankruptcy.
  8. This news will spread quickly, I'm sure http://news.yahoo.com/kodak-hires-law-firm-jones-day-restructuring-advice-183948864.html Who knows more about it?
  9. There are cameras that allow for a lens offset to accommodate either format. My question is this: In practical terms, if you have a camera set up for full ap, is it ever really necessary to change it? If the lens covers full ap (and which of them don't?), then I can't see why a mechanical shift would be necessary. Mask for the format you want, then pan over a smidge either way to compose for that format. Even in 4-perf anamorphic, is it a problem? Granted, one could conceivably have a centration mismatch between camera and projector anamorphs, but it's so small... does anyone see the difference on-screen?
  10. Okay, I was already typing this up, so I'll go ahead post it: To put it in simplest terms, in motion picture cameras, the shutter generally takes the form of a rotating disc with a wedge cut out of it, like a pie with a missing slice. The open wedge is the part that allows light to reach the film. The term "shutter angle" refers to the angular sweep of the open wedge. So, a 180 degree shutter angle would be half of the total disc. A 90 degree shutter angle would be one-quarter of the total disc, and so on. Some cameras have a fixed shutter angle, while others have variable shutter angles. Shutter angle is one of the factors that determines shutter speed. The other factor is the speed at which the shutter rotates. At 24 frames per second, the shutter makes one complete revolution every 24th of a second. If our shutter angle is 180 degrees, then for exactly one-half of that time the shutter will expose the film, that is, the shutter speed will be 1/48th of a second. Here's the formula: Exposure time (or shutter speed) = (Shutter angle/360) X (1/frames per second) Wide shutter angles naturally provide longer exposure times, while narrow shutter angles have shorter exposure times. Besides controlling the amount of light, the shutter angle will also affect the amount of blur a moving subject records on the film. Wide angles allow more blur; narrow angles allow less blur.
  11. Google 'view camera' at wikipedia, then google 'scheimpflug principle' at wikipedia
  12. I also like the idea of modifying the adapter, but, Alex, it's your baby.
  13. Okay, so not your garden variety pin hole lens. Got it. Doesn't change a thing regarding your original question. Grab that PL Ultra Prime and your calipers and you've got your numbers. Want a little extra room? Subtract a couple of thousandths from the OD and wing thickness. Done. Oh yes, and I'm sure you'll watch out for shutter clearance on those short focal lengths, too.
  14. Okay, Alex, a pin hole lens. That's more like a lens port cover than a lens mount. Why all the stress? No joke, you could make this out of cardboard and Elmer's glue and the light rays wouldn't know the difference. I programmed and ran CNC's for several years, and, at the other end, I've breadboarded optical assemblies on my kitchen table with a straight edge, a razor blade, toilet rolls and scotch-tape. Sure, I know all the warnings about dial calipers not being accurate, but everybody and their brother uses them with no problems. Most jobs just don't call for jo block accuracy, and this is one of them. Your CNC guys will grab a piece of scrap aluminum bar stock and knock this out on their lunch break.
  15. When faced with the very same question a long time ago, I paid a visit to a camera shop, asked to look at one of their PL mount lenses, then asked if they minded me taking measurements (they didn't), and, since I just happened to have my dial calipers with me, that's what I did. Now, I'm guessing that the tolerances on an Ultra Prime are EXTREMELY TIGHT. So, if you called those Ultra Prime measurements your upper limit, then held the downside as close as you could (dead on would be good), I'd say you were close enough. Fitting it to the lens is probably the more critical part. Never done it myself, but surely you'd need a collimator with an accurate standard for the flange focal length. Then again, maybe an honest-to-goodness optical guy will be appalled enough at my reply to come in and tell us both how to do it.
  16. Okay. You're correct in pointing out that 16mm can have one or two rows of perforations, but that doesn't change what I said. 35mm always has two rows of perforations, one on either side of the frame. I was referring to the height of the frames as measured in perforation distance or pitch. So, once again, a standard 35mm frame is four pitches high, i.e., 4 x .1866 = .7464 A 16mm frame is one pitch in height, i.e., .2994 As to the specific reason WHY these are the dimensions, one must do some reading, because it involves the long history of motion picture film. In the case of 35mm film, its dimensions and pitch can be traced all the way back to Thomas Edison and George Eastman. They established it very early and it has endured to the present time. Many variations have come and gone over the years. Again, Kodak is one good place to start your research, since they have played a central role in the history of film.
  17. You've correctly hinted that digital fx can be used to do it. There's almost nothing you can't do digitally, given enough time and money, because it can still be labor intensive. There are lots of ways to do it during production, too. 1) Remove the glass entirely, if possible 2) Choose a position that angles the reflection off-axis 3) Flag off the camera 4) Use dulling spray Everybody join in!
  18. There's really no difference in principle between camera lenses and projector lenses. You know that the film is located a just short distance away from the lens in a camera, and that is where the lens focuses an image. The subject is on the other side of the lens, only much further away. The same geometric arrangement exists for a projector lens. The only difference is the direction in which the light rays are traveling. The relationship between object, image, and focal length for a simple positive lens is expressed as: 1/d1 + 1/d2 = 1/f where d1 is the distance from the subject to the lens d2 is the distance from the lens to the image f is the lens focal length Take a look at some simple ray diagrams and play with the formula. Very interesting stuff for anyone who's serious about their photography.
  19. Because a standard 35mm frame covers 4 perforations or pitches, whereas a 16mm frame only has 1 perforation or pitch. Deepak, you're firing off questions left and right. There's a lot of reference material out there that you can directly access for answers. Kodak is one good site, but there are many others. Try that google thingy. I use it all the time.
  20. 16mm long pitch = .300 (print) 16mm short pitch = .2994 (camera neg)
  21. Well, your first calculation will be 2.4/1.78 = 1.348 This is your anamorphic squeeze ratio. After that, things get a little trickier. When I google 'anamorphic prisms,' all sorts of diagrams appear, but no simple formulae. Looks like you'll have to do some digging.
  22. Here is a link you might want to check out: www.zuggsoft.com/theater/prism.htm There you will learn about some of the drawbacks of anamorphic prisms.
  23. Choice (a) will definitely distort the image.
  24. Pretty much agree with Ian's troubleshooting sequence, and the fact that your motor fired up when wiggled suggests a connection problem rather than bad electronics. I would look for something loose, broken, brittle, cracked, etc. in the power wiring to the motor, maybe even inside the motor itself.
  25. Hey, it wasn't my intention to discourage you. More than one CG artist began their career at precisely the point you're at now. If you're motivated, start learning it. For this project, do what Adrian suggested. Build the best-looking prop weapon you can. Do some screen tests with it to refine the look. Then rotoscope in the death ray. This will still involve the challenge of animation, but it will be far less daunting than modeling, animating, tracking, lighting and compositing the entire rig. Again, you can experiment with the ray; blur, color, pulsation, lighting bolt fx, whatever. Comping it in will be relatively easy. This approach has been used countless times in countless movies, so it can definitely give you good results. Unless you're independently wealthy, know now that making movies will constantly challenge your resourcefulness, your skills, your knowledge.
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