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Prism Selection Answered

i thought I posted this already but now I can't find it. wanting to build a pair of these for my dad http://www.ebay.com/itm/like/261411580635?ul_noapp=true&chn=ps&lpid=82 but with the lenses articulated so that he can move them wherever he wants. trying to find a prism that would work correctly without inverting the image (I want it to be disorienting, but......not that bad)

Tags:prism

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gmoon

3 years ago

I believe you're looking for a pentaprism. It's very similar to the viewing prism in an SLR camera -- but those also compensate for the additional mirror which flips up during exposure.

Cailtlindad's comment isn't far off -- just read that the angles in most penta "prisms" don't offer total internal reflection, so the surfaces are just mirrored. Which kinda means they are just complicated mirrors...

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crapflingergmoon

Reply 3 years ago

yeah, the pentaprism was where I was getting lead...but...dem's spensive. guess i'll be cutting up a $5 pair of glasses instead

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Toga_Dan

3 years ago

I've never bought a prism. I suppose there are selections online. But. If I wanted to do this project, I'd probably buy the factory made glasses and hack em to articulate. It's often more costly to buy components than to buy somethin complete. Besides that, they already worked out what prism works.

Back in the day, however, I might have scratchbuilt prisms. I made a few lenses from acrylic rod when I was in high school

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crapflingerToga_Dan

Reply 3 years ago

sure.....but....I'd like to start from scratch. that said, if I can't find what I'm looking for, for cheap, then that's the way i'll go

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Toga_Dancrapflinger

Reply 3 years ago

for scratchbuilt, saw a thick piece of plexi into triangles, then sand wih progressively finer sandpaper, then polish.

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caitlinsdad

3 years ago

maybe go with the diy periscope with two mirrors.