Stackshot and Zerene Stacker

[Chris S.]

Leander,

For 4:1 I put a 4x microscope objective on my 200mm macro and open the lens all the way because if you don't you will get crazy vignetting as you said. I sometimes notice I don't get things as sharp as I like that is why I was asking about REAR curtain sync and Stackshot controller settings.

For 10:1 I move to a wood rig I made and put a 10x objective on the front of my 200mm macro though I have also used a bellows, again wide open f stop. No issues with sharpness as all things are pretty well locked down. Plus I push "go" for a stack and leave the room so I'm not the cause of any vibration.

So it sounds as if your sharpness problems are occurring only with your 4x objective?

My first thought would be that the 4x objective may have issues, but you did say "sometimes." If that's the case, the 4x objective must be OK.

It appears that at 10x, you switch to a higher level of anti-vibration discipline (leave the room, use a wood rig (presumably with camera and subject stage both mounted on the wood?) So let me ask the obvious question: Have you tried your stricter 10x protocol when using your 4x lens? I wouldn't be surprised if your issues go away. In my own work, I use the same anti-vibration cautions at 5x as at 100x.

--Chris S.

[Chris S.]

"The StackShot controller controls the camera and microscope focus block movement"
So you have an automated focus block?

I do have an automated focus block, and love working with it. It's documented here.

Since that documentation, I added a Velmex UniStage with RapidAdjust feature, under the focus block and aligned axially. This lets me move position the focus block quickly and easily. I highly recommend such an approach.

This Velmex UniStage is a screw-drive linear actuator, and moves the focus block backward or forward one millimeter per turn of a crank. The RapidAdjust feature adds a lever for disengaging the screw drive so that the focus block can be moved quickly by hand. Then I mounted a stepper motor on the Velmex UniStage, and built a simple controller that moves the focus block (with attached camera, tube lens, and objective) far back from the subject at the touch of a button. This lets me change lenses without bumping subject or lights. Then another touch of the button returns the macro rig to where it started, with the new lens in focus and the subject remaining centered. This makes work with the rig much more efficient than before.

BTW, I have a bunch of good focus blocks, collected for the purpose of putting stepper motors on them and terminating their leads to work with Cognisys, WeMacro, and MKJZZ controllers. Perhaps this winter I'll actually get to it.


(To avoid highjacking Leander's thread, we can split this off if discussing it further.)


--Chris S.