John,
If the pinhole is too small diffraction will overtake the circle of
confusion. Diffraction will add to sun flare. The lines in the frames
seem to extend to the border. Has the film gone through an Xray scanner?
I should have recognized my own town on the pictures but had to look
twice.
Richard Heather
john yeo wrote:
> A few days ago I made a pinhole body cap for my canon AE-1. I made
> the pinhole as small as I could, it ended up .0065 +/- .0005" f/270.
> Would using one of the formulas to determine the optimal size work
> better for such a small focal length? Or does that only apply to
> longer focal lengths. Larry's site gives .011" as the optimal size.
> That would be better for handheld exposure and looking through the
> veiwfinder but I want the sharpest image possible since it's such a
> small negative. After looking through the viewfinder for a few
> seconds, it's pretty easy to see the image. I have a rubber eye-cup
> that really helps block out excess light. For my first roll I used
> delta 3200. Using the sunny 16 rule, I figured out exposure to be
> about 1/15 sec. I have since made a dial calculator, and it says it
> would be between 1/11 and 1/8 sec. Looking at the negatives, they
> could have used the extra stop. Flare didn't seem too bad through the
> viewfinder, but it is awful on the negatives. I don't know what the
> vertical line is on some of the frames (17,18,28,29) Maybe some of you
> can provide an answer to that. I walked to the post office and took
> the camera with me. Just took pictures of whatever. I even shot some
> cars moving at 45mph!!! All exposures except for the first few were
> hand held. I bracketed a bit, and the exposures range from 1/4 to
> 1/30. They are actually sharper than what the contact sheet looks
> like... my scanner isn't very good. here's a scan of the contact
> sheet:low res 64kb
> http://holgamods.blinkk.net/images/ph35cs-lowres.jpghigh(er) res 192kb
> http://holgamods.blinkk.net/images/ph35cs-hires.jpg John
Received on Thu Jan 11 19:44:45 2001
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