While waiting for more of Robert's tube lens tests, I've continued fiddling with my setup for Mitties. Nothing I did with a 200mm Hoya prime would give me satisfactory results on FF. Objective mounted close to the front element gave massive pincushion distortion. Too far away, massive vignetting. Places in between, proportional amounts of each. Not good.
In frustration, I revisited the Raynox DCR-150 which I discounted long ago as I never got good results from it. Very soft images. But I use it with my Linoscan scanner lens now (where it works very well) and it was almost set up to easily swap in a Mitty anyway. So I searched PMN for relevant spacing info, changed a few bits, and put a 10x Mitty on it.
Blow me down if it doesn't work after all. There's a little field curvature, but nothing drastic, and it's irrelevant because I always stack with the Mitties. Magnification is about right, there's no vignetting at all, and image quality is good to the corners (very good in fact). The Raynox is mounted the normal way round, not reversed.
Gosh! I'll take it - but still very keen to see Robert's upcoming tests of it too.
It clearly pays to revisit past "failures". I must do it more often...
Well I'll be! DCR-150 may be "it" after all
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Hi Beatsy,
It does pay to revisit lenses.
As part of the tube test that I haven't posted yet I ran some 125-150 mm lenses on the Mitutoyo 5x. I had my old faithful Sigma 150 OS sitting around, so why not give it a try as a tube lens, something I tried once maybe 2-3 yrs ago.
And what did I find?
Superb, not trace of CAs.
So I've been searching for tube lenses for 2-3 yrs and one of my finest has been sitting in the cabinet the whole time.
For the record the APO-Lanthar 125 was also superb but I guessed that one before I started the test.
Best,
Robert
It does pay to revisit lenses.
As part of the tube test that I haven't posted yet I ran some 125-150 mm lenses on the Mitutoyo 5x. I had my old faithful Sigma 150 OS sitting around, so why not give it a try as a tube lens, something I tried once maybe 2-3 yrs ago.
And what did I find?
Superb, not trace of CAs.
So I've been searching for tube lenses for 2-3 yrs and one of my finest has been sitting in the cabinet the whole time.
For the record the APO-Lanthar 125 was also superb but I guessed that one before I started the test.
Best,
Robert
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