jeremy_jeffs Posted September 3, 2001 Share Posted September 3, 2001 This may seem like sacriledge but I'm trying to use an RB67ProS as a pinhole camera by replacing the lens with a modified body cap housing a pinhole and shutter arrangement. This has left me with 2 problems; 1. Is there any way of locking up the mirror with the lens off ? - at present miror will only lock in return position with lens on - to remove lens one must cock leaf shutter which drops mirror into position obscuring film plane. 2. is there a way of advancing the film in a standard 120 back without tripping the shutter - ie after a pinhole exposure? hmm any advice gratefully received.Jeremy Link to comment Share on other sites More sharing options...
roger_wong Posted September 3, 2001 Share Posted September 3, 2001 Jeremy,I don't know the answers to your questions. But, if the greater depth of field of a pinhole is all you're after, this may help you sidestep some of your lens issues: Drill a pinhole into the lens cap of a lens. Attach the lens cap to the lens. Attach the lens to the body. I have a 1960s Polaroid camera that uses this pinhole-in-the-lens-cap method to get an aperture of f90 from an f4.7-f45 lens. Link to comment Share on other sites More sharing options...
david_f._stein Posted September 3, 2001 Share Posted September 3, 2001 </HEAD> <BODY> <!--SELECTION-->I would like to offer some suggestions in the form of an article I wrote for the Luminous Landscape web site on <A HREF="http://www.luminous-landscape.com/pinhole.htm">Pinhole Cameras</A>. THANKS.<!--/SELECTION--> </BODY> </HTML> Link to comment Share on other sites More sharing options...
j_m_brown Posted September 4, 2001 Share Posted September 4, 2001 Well, here is one way to accomplish your mission: 1) With the lens on and the darkslide in place, cock the shutter and compose the shot normally. 2) Remove the lens and replace it with the modified body cap. For your pinhole shutter, use a piece of black tape over the pinhole. 3) Remove the darkslide. 4) Trip the shutter button on the camera body to raise the mirror and the light baffle that lies behind it. 5) Make the exposure by removing and replacing the black tape. 6) On the film back, find the small button under the tip of the film wind lever. Press it to the left to release the wind lever, then advance the film. 7) Repeat 9 times. 8) Relax. Unlike Hasselblads and Bronicas, it is impossible to jam an RB67 if you mate a cocked part to an uncocked one. I don�t agree with Roger�s suggestion to use a small hole in the body cap for your pinhole, because the thickness of the cap will increase diffraction distortion. And hey, the last thing you want here is to compromise optical quality, right? <g> You will get better results by using a very thin material such as brass shim stock, about 0.010" to 0.020", available at auto parts stores. You can use a needle to punch a hole in it, but then you should lightly sand around the hole on both sides with crocus cloth to deburr its edges. Push the needle through from the opposite side, sand again. Repeat several times to get a clean pinhole. Radio Shack sells (or once sold) a 30X lighted microscope, Cat. No. 63-851, for about $10, that will make inspection easy. Tape or glue the brass piece to the inside of the body cap, then place the black tape shutter on the outside, so as not to allow any sticky stuff to contaminate the pinhole. To get a longer effective focal length, just rack out the bellows. All the way out, double the exposure time. If you use a fairly large sewing needle to make the pinhole, try bracketing sunny day exposures from 30 sec. to 4 minutes or so with film in the ISO 100-400 range. Make your shots more interesting by taking advantage of the unlimited depth of field. Try including objects that are only a few inches from the pinhole, along with others all the way out to infinity. Link to comment Share on other sites More sharing options...
Spearhead Posted September 4, 2001 Share Posted September 4, 2001 Why do you want to do this? You can buy a Zero 2000 in 6x6 or 6x9 format inexpensively and it takes less space and weights far less in your bag than a Mamiya lens. I carry mine along with my Mamiya most of the time. Much, much easier. Music and Portraits Blog: Life in Portugal Link to comment Share on other sites More sharing options...
jeremy_jeffs Posted September 4, 2001 Author Share Posted September 4, 2001 Thanks for all your advice - I finally got things sorted out. Jeremy Link to comment Share on other sites More sharing options...
jeremy_jeffs Posted September 4, 2001 Author Share Posted September 4, 2001 Thanks for all your advice - I finally got things sorted out. Jeremy Link to comment Share on other sites More sharing options...
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