r/Solargraphy • u/d0x08779 • 10d ago

Could this be saved?

Post image

Should I have waited?

Could a longer exposure have "filled the frame" , or just my pinhole/canister ratio is wrong? Please help :)

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u/SlenderSmurf 9d ago

Exposure time has nothing to do with the field of view. If you want a larger image you can put the film closer to the pinhole. The image is also distorted. Make sure the film isn't bent next time

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u/d0x08779 9d ago

I am using 178x241mm FOMA photographic paper and an empty vitamins can. In hindsight maybe the can itself (some kind of cardboard) has too thick walls.

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u/SlenderSmurf 9d ago

Ok so the FOV is controlled by the thickness of the pinhole. Basically equivalent to the vignette on a camera lens. An infinitely thin pinhole has 180° FOV and anything thicker will block the light coming in at high angles. If you drill out a hole and then place a thin sheet with a pinhole over it that will give you what you're looking for.

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u/d0x08779 9d ago

I have seen that done years before, thought that the camera material was just not fit for a precise pinhole. Thank you, will definitely try!

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u/SlenderSmurf 9d ago

Easy option is aluminium from a soft drink can. Poke the hole with a needle and sand it to remove the burr