Experimenting with glass, adapter and an EOS lens

todtodson

Member
My first post here, here we go!

I just saw the thread about focal reducers today, pretty cool stuff imo! Read through some replies and saw that someone mentioned you could use biconvex lenses (I think at least :p) to reduce the FOV. I didn't give this too much thought at first, but then I remembered I had an old Jag35 35 mm adapter, with biconvex glass in it. I took it out and started playing around with putting it inside my EOS>m43 adapter, turns out it works. There's a small problem tho, the distance between the glass and the lens is too small and causing everything to be blurred. Here are some pics with the standard 18-55 EOS kit lens, at 18mm.:

P1000676.jpg
This is with the glass inside the adapter, it's wider but also blurred. :(

P1000677.jpg
This is without the glass, not as wide. Blurred, but this is because I didn't bother to focus properly.

I am out of ideas for now, so I'm turning to you guys to see what you have to say. I was thinking that extending the adapter somehow would work but I have no clue how to do that.

Peace

Update:
Just realized I don't need to extend the adapter, but to shorten it! I will have to sand it down about 1 or 2 mm to be able to focus to infinity!.

Update 2:
Started sanding down the adapter now, I think I might have to sand it a tiny bit more in order to get the sharpest image possible. But I'm getting there!

ykZAG.jpg

Focus ain't quite right yet, but soon!

yIZlo.jpg

Close up of my dog, no problems here.
 

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Could you show us some pics of your adapters? I'm having issues getting what you are talking about. I also have some issues with the flange on my adapter for Nikon.
 
convex.jpg

See if this diagram helps you to understand more.

What I did basically was to put a biconvex lens inside my adapter to get a little smaller crop factor. Also I am not quite sure what you mean by flange, but if you're having problems with focusing try to deattach your lens from the adapter and move it forward a couple of millimeters to see if you can get a sharp image. If it becomes more blurred, you probably need to move your lens closer to the sensor. If you're fine with modding your stuff just sand it down a bit and you should be able to focus properly. Be aware though, I sanded down mine so much the screw holes disappeared! Nothing tape couldn't fix tho.

Edit: I have no idea why the image being scaled down! Here's a link to high res: http://i.imgur.com/t9qFL.png
 
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