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Rear Optic Size? DIY Lens (Yes, I'm Crazy...)

Started Feb 3, 2020 | Questions thread
OP PhotoW Regular Member • Posts: 114
Re: Rear Optic Size? DIY Lens (Yes, I'm Crazy...)

petrochemist wrote:

PhotoW wrote:

I've decided that, budget allowing, I'm going to try to source parts to create a lens (I'll probably try to base it on an existing patent).

I have a Sony a7iii - how big/small would the rear optic have to be in order to fit the E-mount? What image circle size should I aim for? What size should the rear optic be (and what type of optic should it be to project the image onto the sensor)?

I don't have any experience with lens building, but I just want to have some fun and create something semi-usable. Reignite my passion for photography. Any advice on the size and type of element would be very appreciated!

There are too many variables to determine ideal lens diameter at this point. A pinhole is capable of covering well beyond the sensor, so it's not critical for getting an image.

You may find the homemade lens group on Flickr a useful resource - it has quite extensive tips on building your own optics.

This looks like such a great resource - thanks! I've already learned something about different focal lengths for each element in the optic, and I'm only 10 minutes in!

If anyone has any other resources to share, I'd love to see them, though I'm a beginner and likely won't understand it if it's too complex (the above link is a perfect example of simplicity).

 PhotoW's gear list:PhotoW's gear list
Sony a7 III Sigma 35mm F1.4 DG HSM Art Sony FE 90mm F2.8 macro Sony FE 85mm F1.8 Tamron 28-75mm F2.8 III +1 more
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