Hi all, For those that are interested, I'll be turning a hotel room in Montreal into a giant pinhole camera on April 28. Details of the project can be found at the following URL (Zernike has offerd to build and host the web site which is still in progress): http://www.zeroimage.com/Guy/PinholeHotel.html
We will be a team of four photographers. The room will be on the 6th floor, kindly offered by Wyndham Montreal Hotel, for the period from saturday noon to monday noon. This will give us lots of time to do the set-up ahead of time. The image will be printed on Ilford RC VC paper, with a yellow filter on the pinhole. We'll be working with 3 strips of 50 in. x 9 feet from a roll of 100 feet. The pinhole should be about 0.1'' diameter with a focal length of 10 feet. This works out an f-stop of F-1200. With a yellow filter and paper at ISO 3, this should work out to an exposure time of about 1.5 hrs on a sunny day. There are no reciprocity failure charts for paper, but it is just as real as for film. So I'll have to make some tests before next week but I expect to end up with an exposure time of maybe 8-12 hrs. I just hope that it'll be sunny weather outside. If it's rainny, we can either move the paper closer to the window and shorten the focal length to open up the F-stop or work with a larger pinhole diameter and get a somewhat more blurry image. The plan is to calculate the focal length/F-stop based on the weather outside so as to be able to open the shutter at 00:00hr on Sunday April 28 and to let the exposure run until 24:00hr. We'll be using RC paper and, once we have the paper negatives, we'll make a 4' x 8' contact print from each of the three 50'' x 9'. (You soak the paper negative and the unexposed paper positive, squeegee them together and do you exposure). I have not yet got around to making tests but I do not see any major difficulties here, assuming that I managed to get through the first stage of processing the paper negative. We'll be using wallpaper tanks to roll and unroll the paper in the chemistry. Washing and drying will be the tough parts. The final paper negative and positive (3 each) will be mounted on thick board to make a twin triptych - either all 3 positive and all 3 negative or alternating 1 positive and 1 negative. Cheers, Guy