Common fly, its proboscis and leg

dack9 · Post by **dack9** » Thu Oct 01, 2015 11:13 am

skrylten,
Thank you very much for the correction!

Lou Jost · Post by **Lou Jost** » Thu Oct 29, 2015 2:51 pm

Beautiful images! May I ask why you have an extension tube in the set-up? That's something new for me. I had thought the best results would be with the tube lens focused at infinity.

rjlittlefield · Post by **rjlittlefield** » Thu Oct 29, 2015 3:07 pm

Lou Jost wrote:I had thought the best results would be with the tube lens focused at infinity.

The optics will have least aberration when the tube lens is focused at infinity. However, when using objectives with fairly low magnification and small NA, only a small amount of aberration is added by moving slightly away from infinity focus. So then it's a matter of tradeoffs: accepting a probably invisible bit of added aberration, in exchange for doing a better job of filling the sensor.

--Rik

Lou Jost · Post by **Lou Jost** » Thu Oct 29, 2015 5:47 pm

Thanks Rik, that's good to know.