In the course of recent exposure/development tests, as I have been working my way back into LF, I have found that my EI goes up significantly when I photograph lighter subjects outdoors, e.g., a light-painted house wall, white-painted door, filling a good part of the frame with most areas Zone V and above, as compared with, say, an indoor portrait in window light in which half or more of the frame is Zone IV and below. In the latter, EI 200 is just right, while the exteriors would have been fine at EI 400 -- I see a Zone III-read area coming up as IV in the neg.
I use a Tachihara Hope 4x5 with a 210 Komura Commercial, I shoot HP5+ and one developer. The bellows appears to be a replacement; the front is mounted slightly skewed. Shutter speeds were recently calibrated, as was my Pentax Zone VI-Modified Spotmeter. .
I checked Adams and Stroebel on flare last night. Adams speaks of bellows flare having potentially significant effects, but seems to indicate that the film edges may more affected, which is not my case. Perhaps it could be some overall lens flare, but I wouldn't expect this in the Komura, which, if I am not mistaken, is multicoated, and I have had it a long time; contrast appears good with no appearance of flare in subjects like a window light portrait including bright clothing, curtains, etc.
Any ideas? What other text might I devise? (I wish I could reverse the effect -- how nice it would be to get EI 400 inside!)
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