Light streaks in middle of photograph.

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Grandpa Ron

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I have had this happen before but I do not know why. In the middle of each photograph is a light streak in the form of an X.

The 35 mm was shot with Arista EDU 200 with a .014" pinhole for an f of about 250. Exposure about 25 seconds.

35mm2 middle.jpeg


The mage did not scan well into my computer and the scan structure shows. However you can see the light X on the bird house. This is one of the better photos, is some of the others the light X is more pronounced.

The second shot is from my 4x5 view camera, this is a .013" pinhole for an f of about 450. The exposure was 40 seconds with Arista EDU 100 cut film. A completely different camera but the same X shaped light streak in the photo.

Photo 102ap.jpg


So my question is, does anyone know what causes these X shaped light streaks in both cameras?
 

Kino

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I seem to notice a theme of bird-related habitat.

Any chance there was wire or a screen in between you and your subject each time?
 

Jerevan

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Very reflective piece of metal around the pinhole, perhaps? Is the pinhole totally round?
 

Luckless

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The top one has an effect that reminds me of using focus masks on a bright pinpoint light source.

A specular reflection photographed through a screen of some kind maybe?
 
OP
OP

Grandpa Ron

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Sorry no screen etc. Just roaming around the State Park. This was at test of my Pentax SLR with a 2 inch tube attached to the front for an f 250. The exposures are left to right. are about 10 sec, 40 sec, and 20 sec. based on a 20 sec. light meter reading. The tube was painted flat black in and outside. The objective was to bracket the shot +/- 1 stop to test the light meter reading. It seems to me that f 250 is where fuzzy stops and soft focus begins

These negatives scanned a little better but the light X is still there. I would think it was the camera set up but I had the same issue with my 4x5 view camera. I am suspecting some sort of diffraction but that is only a guess.
proof 4.jpg
 

MattKing

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Most likely a problem with the shape or edge smoothness of the pinhole itself.
 

mcfitz

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For the ones taken with the Pentax, the flare is consistent from one negative frame to the next. It is in the same position, and is a clear and sharp X.

It could be a problem of the camera itself. I was using an old Yashica with an extension tube for pinholes, and always had the same flare in all images. Same place, same pattern. After some trial and error it turned out to be a light leak from the view finder window, which was solved by using the plastic cap that slots over the view finder, provided to prevent light entering the view finder, which was no longer light tight.

The flare in your image from the 4x5 is different, blurry and amorphous. I don't know what to suggest for that one.
 
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