Alex,
The results from today.
Unfortunately after a thorough search I could not find any material of suitable diameter to connect the 50mm to the 200mm. I checked SRB ( UK manufacturer of any adaptor you like ) and the ring is listed at £21:95 + £2:50 postage. Not sure what that is in $, but I bet a lot more than you can get it for.
With all my M/F lenses out in the workshop time for a bit of a think.
I was not too keen on using tape to secure the 50 to the 200. Glue residue etc. So I dug out my lens reversing ring and did some comparisons of magnification with various combinations.
Results :
200mm with reversed 50mm - measured field of view 11mm with a working distance of 40mm.
Reversed 28mm - measured field of view 16mm, with a working distance of 55mm.
Revesed 28mm + 14mm tube - measured field of view 14mm, with a working distance of 50mm.
I did try a 24mm but feel 28mm is about as far as you can reasonably go.
Now maybe its that bit of Scot in me that says £24:45 is a lot to pay for a small increase in magnification, but I have decided I will stay with reversed 28mm for now. I know I loose auto diaphragm, but I think I am more likely to use the set up in resonably controlled conditions, ie not with fast moving subjects. I got into photography in the age of pre-set lenses so not really a huge problem. If I find a coupling ring at a reasonable price then I will get one.
Attatched are a couple of pics. By the time I had got this far, it was dark and tipping it down with rain, did not facy wandering around with a torch in that, so its a shot of a micrometer. Afraid the images are quite large, despite compressing the resized images to 30% in save for web. To give some idea of scale the numbers on the mic are 1.52mm high. Aperture used here is f8.
So just a flash bracket to make now.
Don
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