james smyth Posted April 30, 2007 Share Posted April 30, 2007 My school has a bunch of bolexs and an intervelometer I use frequently. At 1/3 of a second at its fastest, it's not always easy to stop down as far is needed for a proper exposure. I was just thinking, I wonder if I could make a pinhole lens for the camera, has anyone ever tried to do this? I like pinhole photography and I think it would be interesting to bring this concept the moving world. Link to comment Share on other sites More sharing options...
Joseph Winchester Posted April 30, 2007 Share Posted April 30, 2007 I've done it with my Canon XL2 and a f384 pinhole. The major thing was I had to turn the gain waaaay up to get any image, and alot of post to get it looking right. I'd imagine you'd have to have some fast film in there and push the crap out of it to get an image with a f256 or higher pinhole. I have a 4x5 pinhole camera that is an f231 and with ISO400 the exposure in bright sun is 2 seconds. A cloudy day is 6 seconds. Link to comment Share on other sites More sharing options...
Premium Member Chris Keth Posted April 30, 2007 Premium Member Share Posted April 30, 2007 I've done it with my Canon XL2 and a f384 pinhole. The major thing was I had to turn the gain waaaay up to get any image, and alot of post to get it looking right. I'd imagine you'd have to have some fast film in there and push the crap out of it to get an image with a f256 or higher pinhole. I have a 4x5 pinhole camera that is an f231 and with ISO400 the exposure in bright sun is 2 seconds. A cloudy day is 6 seconds. Exactly my concern: exposure times. I shoot pinhole on formats from 35mm to 8x10 (inches) and exposure times can easily get into minutes if the film is slow, the light is dim, you use filter(s), reciprocity failure, or some combination of these factors. It's something to try and if it doesn't work, oh well. Link to comment Share on other sites More sharing options...
Premium Member Charles MacDonald Posted May 1, 2007 Premium Member Share Posted May 1, 2007 . At 1/3 of a second at its fastest, it's not always easy to stop down as far is needed for a proper exposure. I was just thinking, I wonder if I could make a pinhole lens for the camera, has anyone ever tried to do this? I like pinhole photography and I think it would be interesting to bring this concept the moving world. an exposure of 1/3 of a second is at the short end for a pin hole.. You could get some regular film and try to find a good size exposuing in a plain box, and then use the pinehole in the bolex if you can find a good comprimise of Fast enough appature without being too blurry. You are outside the documentation so you are on your own. The infinite depth of field of a pinehole would look weird. Sounds like a great place to try the 500D stock. Link to comment Share on other sites More sharing options...
Anthony Schilling Posted May 1, 2007 Share Posted May 1, 2007 My school has a bunch of bolexs and an intervelometer I use frequently. At 1/3 of a second at its fastest, it's not always easy to stop down as far is needed for a proper exposure. I was just thinking, I wonder if I could make a pinhole lens for the camera, has anyone ever tried to do this? I like pinhole photography and I think it would be interesting to bring this concept the moving world. These Bolexs do open shutter exposure on single frame? I do it in S8 with a nizo, slow film and an ND .9 filter at about f11-16 for about 2 seconds in cloudy conditions. I like your concept. Link to comment Share on other sites More sharing options...
Bernhard Zitz Posted May 1, 2007 Share Posted May 1, 2007 If you DIY a Pinhole(which will have rather random F)you can try it first on a DSLR to figure out the rating. Link to comment Share on other sites More sharing options...
Bernhard Zitz Posted May 1, 2007 Share Posted May 1, 2007 I just tried a DIY pinhole made of aluminum foil on my DSRL. I made a larger hole in the cover for the lens-mount and taped some aluminum on it and made a hole with a needle. This gives me a picture-width equivalent to a 50mm lens. In bright sunlight at 800asa I had 1second. The image is rather blurry, I think the hole wasn't small enough. I guess to have good sharpness in 16mm the hole has to be very small, so exposure time will increase. Theoretically you should gain sharpness and speed if the pinhole is closer to the film plus it gets more wide-angle cheers, Bernhard Link to comment Share on other sites More sharing options...
Bernhard Zitz Posted May 1, 2007 Share Posted May 1, 2007 Again me, i had some good fun shooting tests with my DSLR this afternoon. I also intent to do this in 16mm. After googeling the topic I found that there is an optimum hole diameter according to the focal length. I found a calculator to calculate pinhole-stuff http://www.mrpinhole.com/calcpinh.php A pinhole made with a c-mount body-cap would have a focal-length of aprox 18mm (0.7inches). If you type this in the calculator it says 0.179mm optimum diameter which gives at 18mm focal-length a Fstop of 101, that makes aprox 1/4 second in sunlight at 200asa... On a bolex you could put the pinhole in the filterholder that would give you a wider angle of view. Anyone knows the exact distance of filterholder to the filmplane? Try as well the camera design wizard http://www.mrpinhole.com/index.php Link to comment Share on other sites More sharing options...
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