Wallace the 6 inch f/2.8 telescope, building it, and hiking with it

Re:Wallace the 6 inch f/2.8 telescope, building it, and hiki... by platinum95 on Tuesday June 30, 2026 @05:03AM (#48730181)

220 is a roll film, essentially the same as 120 film, just a longer roll. It's 6cm wide, and picture format depends on the camera/lens, varying from 6x4.5 up to 6x7 (and beyond, for panoramic shots).

So for use with your telescope, it'd need to produce an image circle that'd cover at least 6cm.

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Re:Wallace the 6 inch f/2.8 telescope, building it, and hiki... by chantepierre on Tuesday June 30, 2026 @05:32AM (#48730347)

Thanks for the clarification. I don't think so, my largest eyepiece has a field stop of 39mm, and I'm taking advantage of the fact that edge illumination falloff is not perceptible in visual astronomy when the f/D ratio is low.

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