Another Zeiss 10x Test - Fruit Fly Ovipositor

[AlP]

Another test with the Zeiss 10x Planachromat infinity objective on a broken Canon 55-200 zoom with a Canon 5D MK IV. Fruit fly (type unknown) aedeagus. 62 steps at 30µm.

[rjlittlefield]

The result looks good, but I am wondering why it looks as good as it does.

I assume this is with your 10X NA 0.20 objective. Nominal DOF at NA 0.20 is only 13.6µm. That's with the 1/4-lambda rule, for green light. At 30µm, the same calculation says over 1/2-lambda wavefront error at maximum defocus. 1/2-lambda will give severe blurring, but on the hairs I do not see any trace of focus banding. This is confusing to me.

Are you sure about the 30µm? What method are you using to step focus?

--Rik

[AlP]

Are you sure about the 30µm? What method are you using to step focus?
--Rik

Yup, totally sure of 30µms. I am using the Wemacro rail and the software that came with it. Objective is attached to a broken (autofocus) 55-200mm lens set at 200mm and infinity. I made a mistake, this is actually a female ovipositor. How embarrassing, luckily I know smart people. Hopefully I can edit the main page subject line. If not could you do it for me Rik? Thanx. Al.

[rjlittlefield]

Thanks for confirming the focus step. I'm still puzzled.

You should be able to edit the main subject line, just like editing the main body of your post.

--Rik