The next meeting of the WWIG will be on Wednesday October 6, 2010 at 6:30pm at my home (N2207 Pammel Pass W.) The usual format will be followed. We'll start with a social hour at 6:30-- with refreshments by Susann Annis and an opportunity for leisurely review of prints brought by members. Next Ron Reimer will be speaking and moderating a discussion. I will give a brief presentation and demo on Micro Four-Thirds Digital Cameras. I hope to have one more person do an introductory talk about a couple of complex problems that I would like to explore in detail in future meetings-- more information about this later. Finally, there will be an Open Mike for presentation of prints and digital images.
FUTURE PLANS: I had previously asked Bob Hurt to speak at our November meeting and he kindly agreed to do so. Recently, however, I suggested that we put this off until Spring because some of us did see his quite remarkable slide show at the N4C meeting last week.
TOPIC OF THE MONTH/ OCTOBER: I'm sorry to give you this assignment on such short notice but, because members have enjoyed this exercise in the past, I do want to go ahead as planned. The topic/assignment is to take a photo at 11:00 am on Saturday October 2nd-- no matter where or of what. If you absolutely can't go ahead and take your photo at the backup time of 1:00 pm on Monday October 4th. I don't know about you, but I have no idea of what the results will be, either for myself or the group. Obviously the more participants the better the resulting display. Finally, there is this: One of my goals as a photographer is to be rigorous about having a camera with me at all times-- something I very rarely do even though hardly a day goes by that I don't regret when I encounter potentially terrific shot. This topic is an exercise that can help remind us of the possibilities of photo serendipity.
I've got to go. More later. Please come back to this blog for updates.
Byron
This is not a comment on the above (I'll be there) but a report for any remaining analog photographers (or those who remember the methods). In recent times I have become aware of increased density at the edges of my 120 rollfilm negatives, particularly evident when I scanned them. I could compensate in printing by edge burning, but that increased the complexity of manipulation under the enlarger. Since it was the same regardless of camera, film, developer batch, and other parameters, I decided to examine developing tanks. In recent years I had been using Patterson tanks with adjustable plastic reels; they were easy to load with the walk-on method from the edges, and agitation was by twirling the reels with the provided rod. Even better was the rapid filling and decanting of fluids with the built-in funnel/cap. To compare the Patterson system with the older Nikkor tanks with center-out loading reels (which takes a bit of experience)in stainless steel tanks, with which agitation was by inversion, I set up a parallel test. I exposed two rolls of 400TMax, EI 250, in a Hasselblad, outdoors in a heavily overcast day, aiming at a Kodak gray card with the lens set completely out of focus to distribute the light evenly. I metered all across the card to ensure even lighting. I developed both rolls concurrently in fresh D 76 1:1 at 12 minutes, temp 71 F (the temp of cold tap water on that day), one roll with the Patterson tank, one roll in a Nikkor-style tank, each at the bottom of a two-reel tank. Agitation timing was the same for each, my long-used method of 60 sec. agitation at the start, and 3 seconds every 30 seconds until done. I used water bath pre-soak, and stop, and Rapid Fix for 7 minutes, finishing with a 2 hour wash in a Kostiner film washer. After a dunk in dilute Photo-Flo the films were hung to dry side by side.
ReplyDeleteI then used a densitometer to measure the optical density at the edges and center of each frame, and calculated the average of 10 frame readings (Nikkor) and 11 frames (Patterson). In summary, with the Nikkor tank, one edge averaged 5.8% more OD than the center, and the other edge 2.1% less dense than the center. With the Patterson tank, one edge averaged 32% greater OD than the center, and the other edge 24.5% greater OD than the center. In both runs, all the individual frames showed variances in the same direction as the averages.
Conclusion: Nikkor tank development is more uniform than Patterson, and the latter system overdevelops edges (or underdevelops centers) significantly, probably at least one stop of exposure. The Patterson system does provide a sealing cap for their tanks which should be used, but it is clumsy. Anyone interested in buying 6 Patterson tanks of varying size and 21 reels?
Jim Terman