About 10 months ago I posted an image of a blob of superglue that had set, on a microscope slide, in an unusual way.
Here's a couple of shots showing the contorted surface of that same blob.










Sorry it's been so long!

Thanks for having a look,

Roger.

......thought about utilising one of those £30-odd follow focus units & putting a big protractor on instead of the white ring for marking A & B stops, but using a fitted gear ring on the lens, not those stupid ones with the knuckle like a cable tie....then move the focus ring with the protractor...........

Roger.

.....but then you can cover the difficulty with DOF with stacking!
(If you can manage a small enough step-size)
Can't you?

Roger.

Here you go!







K5, Pentax Auto Bellows M, Amsope 4x Achromatic Microscope Objective,
Stack of 16 with Combine ZP.
Elements 11.

Thanks for having a look!

Roger.

Thanks, Steve.

Good time of year to start a "Flowers" project, eh?

Just use the Godox TT600. There seems to be a reasonable amount of IR in there.....?!

From a flowerhead of Alstroemeria






K5, 100mm D FA Macro.
IR72 filter.

Stack of 16 in Combine ZP.

Elements 11.


Please let me know what you think of it......


Thanks for looking,

Roger.

Here you go, Steve!

The formula to avoid diffraction:

f* = f x ( mag.+1)

f* is effective aperture, best to keep this below, say, 16.
f is aperture as set on lens.
mag is magnification.

A little basic algebra enables you to start off with the max f number to avoid diffraction, then backwork to change the f stop set or the magnification, to suit.

Hope this helps,

Roger.

Thanks, David & Steve.

Sorry Steve, I think I've misled you in your calculations.... that FOV figure was for the width of the frame, as viewed here, which gives a mag,. of roughly 5x.
As I said, taken with a no-name objective, which obviously has no diaphragm to adjust the exposure or, more importantly, increase the DOF! Hence the tiny depth of field. And then I'm restricted to about 30 max. images for stacking because of my ancient computer
I didn't want to schlapp through doing multi stacks, as this was only a test to see how it got on with the fern shot.

Thanks for the interest shown.
More to follow, no doubt!

Roger.

Roger

The mechanism a fern has for distributing its spores (seeds).

The "sack" the spores are in is semi-surrounded by a ridged, spring-like structure, which, when the spores are ripe, expands & throws itself backwards which ejects the spores into the air & away.
Various stages of this operation can be seen here.
Two sprung-open "springs " with ridges, centre back.
The capsule of spores still ripening & with the spring "girdle" still in place, bottom left.

Field of view for the whole, SOOC frame is about 3mm.




K5 on Pentax bellows with a 4x 0.1 NA microscope objective.

Stack of 16 in Combine ZP, then Elements 11.









Thanks for looking,

Roger.

Nicely done, Steve!
And was this 100 x 1/24th. mm.?

Roger.