I acquired this lens many years ago to use with the Pentax 645 - it is a Russian made "ARAX 500mm f5.6" - at least that is what it says - but my experience shows that it is more like 600mm f6.7-to 8 - and I have used it with adapter on the Pentax. I have also used it on my old Canon 60D.

I recently got an adapter to use it on the Sony A77II so I went out to see what I could get ......This is manual focus with manual exposure settings - and I was very lucky to find a Green Heron to do some modeling ..... I am not happy with the noise I am getting with the Sony now for some reason 8-(

These are from a braced monopod, 1/320, ISO 400 at whatever the f-stop really is - 6.7 or 8, DOF is very thin - subject distance about 45 feet and these cropped about 20% .....as always, shot as JPEG with judicious PP in Elements 9. Lighting was late afternoon with Sun low in the sky and color corrected for the warm light.

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