Hi friends, I thought that some of you might be interested in an update on our project to turn a room of the Wyndham hotel in Montreal into a giant pinhole camera and to do a wall size pinhole image of the Montreal landscape.
Things are going on as well as could be at this stage and the only dark spot I see is that the weathermen are calling for rain on Sunday, which could play some tricks on us if the window is dripping with rain all day long. As the rain interferes with light flowing through the pinhole, there is no way to anticigarette how the image will ultimately shape up on the emulsion. To make things more difficult, low light levels associated with rain may require inordinate exposure times because paper has huge reciprocity errors beyond 60 minutes exposure times. At 60 minutes, the reciprocity correction factor is 9.5 for a corrected exposure time of 9 1/2 hrs... We'll be using 3 strips of 50'' x 98'' to make the print (it'll be paper negative which will be subsequently contact printed into a paper positive). The paper will be tacked on a frame 150'' x 98'' held vertical with two autopoles. To get the maximum view of the cityscape, we'll be working with a very short focal length (so to speak for those not accustomed to large format). The focal length will be somewhere between 36'' and 48'', to be finalized on site. Optimum pinhole size for a 36'' focal is 1.27 mm which gives us an F/stop of F/720. This is quite manageable on a bright sunny day (6 1/2 minutes, uncorrected for reciprocity), but on a rainy day, this could well rise to 2hrs. Add reciprocity, the theoretical exposure time jumps to 26hrs... -:( The shutter will be opened at exactly 00:00hr on Sunday, April 28, to celebrate the 2nd Worldwide Pinhole Photography Day and we will let exposure run until Midnight exactly. It'll be a 24hr exposure, but my tests in the past few days indicate that not much of the night time exposure will show up on paper (unless we were to use a larger pinhole for night time). The plan is to have a bunch of 8x10 sheets attached to the side of the frame and to process one every hour or so to check how the image build up and to modulate exposure as the image builds up until completion. On a bright sunny day, this should occur around noon time, but if it's rainy, we may barely have enough of the whole day. We'll be spending most of the day today setting up the room, the pinhole and the wood frame and we should be ready well in time for 00:00hr tonight. Exposure will take place all day Sunday and we'll start processing the long strips of paper Monday evening and continuing the subsequent two evenings. We'll use large 50'' x 10" tanks made from boxes used to store rolls of photographic paper, lined up with heavy plastic. The tricky part will be the washing stage, to ensure satisfactory washing. We'll that's it folks. I hear that the team doing the Great Wall of China giant pinhole will have something like 130 people. Hmmm... A lot more than the five of us in this project! -:)) If you want more information, go to http://www.zeroimage.com/Guy/PinholeHotel.html or check the reference on the site of Pinhole Visions at http://www.???????/ Happy pinhole day to all, Guy
