Originally posted by Nass Yes, reversing the macro m50 f/4 at 5.6 on tubes worked really really well, it was the major find. Backs up what I think you found a few weeks back that it's as good reversed as it is normal way round (or is my memory failing here?). The lack of CA really surprises me when I compare it to the CA on the -m 28s, but I guess it's a specialty macro lens so maybe it has stronger coating or something?
Is the lens the Macro-Takumar (1:1) version or a later 1:2 version? - I don't know if there are actual lens design changes between versions.
Quote: The el-nikkor is the 50 f/2.8 enlarging lens reversed, it's well known to be an excellent little reverse lens for macro without getting into three figure sums or exotic expensive stuff. Do bear in mind the caveat that these tests are not as exact as I'd like. I need to do them with repeatable 1 micrometer steps and although I now have a stage to do that I need to have some bespoke metal plates cut first to fit the stage onto my setup, bah
As I recall there are two basic versions of el-nikkors, 4 lens elements and 7 lens elements, that's why I ask - in case somebody wants to buy one.
Oh, and thanks for the tests!