Swedish wild flowers

[Stephen_De_Lisle]

My first post here on the forum- some images of small wild flowers from my yard in Sweden, taken with my stereomicroscope at magnifications from 4x-10x (measured on the camera sensor). I am a biologist by profession and I have a work scope set up in my basement, which I have been using for hobby photography in my spare time. I have been trying to get better at plant IDs; hope these are correct!

Technical details:
Olympus SZX-16
Plan Apo .8x .12 NA or 2x .3 NA objectives
ring light illumination (schott visiLED slim mounted on the .8x objective, a photonic light with a schott focusing mirror taped on, mounted on the 2x objective)
Nikon D850
LM scope adapter to the trinocular port
focus stacks in Zerene.
rotating nosepiece to align the objective with the photographic optical path.

Chickweed:

Wood anemone:

Bird-in-a-bush:

heal-all:

Siberian squill:

Dandelion:

cheers,
Stephen

[klevin]

Interesting pictures! Good examples of the amazing diversity within plants and flowers, color, structure and such.

[rjlittlefield]

Lovely images!

I am puzzled by this one bit of technical detail:

rotating nosepiece to align the objective with the photographic optical path

I have no experience with the Olympus SZX-16. I see that it appears to be a CMO design (common main objective), and I would have naively assumed that the camera port is positioned so as to look straight down through the objective. But from your comment I gather that is not the case.

So, how is it actually? Is rotating the nosepiece part of some standard practice that is designed & documented by the manufacturer? Or is it an ad-hoc technique discovered by yourself or other users?

--Rik

[Scarodactyl]

I would have naively assumed that the camera port is positioned so as to look straight down through the objective.

I don't think any CMO system is designed like this*. Having to fit two light paths in is already asking a lot--putting a third right in the middle would require putting the viewing paths further into the less corrected corners of the objective. A few systems do have a third path for fluorescence illumination but presumably this is offset back a bit since it isn't being imaged through. Some more advanced systems thus offer the option to center the objective over one light path for photography, and if you have a rotating nosepiece it's easy to just have a detent that puta the objective pretty much at the center of one light path or the other. The other option is a horizontal slider for the objective or for the body above the objective (kind of an insane solution but it means the image position does not change when going into photo mode.)

*the Olympus MVX10 macroscope has a really neat trick where you can put it in 'stereo mode,' which I assume is using the dual polarizer trick where two half circle polarizers of opposite orientation are inserted above the objective and one full analyzer below each eyepiece so each gets light from only half the main objective, producing a stereo effect. That's sort of coming at it from the opposite direction though.

[Stephen_De_Lisle]

Lovely images!

Thanks!

Scarodactyl has it right- it is just a revolving objective holder (Olympus Szx2-2RE16), with a click stop that permits the objective to be centered over just one of the two stereo optical paths (or the normal position covering both paths, of course), eliminating the shift that would otherwise occur during a focus stack with a stereomicroscope, and probably also decreasing aberrations (I haven't tested that latter speculation but I think I remember seeing that someone else on this forum has).

[Scarodactyl]

It's a very nice system as your images attest. Sorry to go off on an equipment tangent, I really like your photos. They're very nicely composed, especially for being taken under a microscope vs a more traditional horizontal setup.

[rjlittlefield]

OK, thanks to both of you for the information.

I have been basing my naive expectation from what is written at https://www.microscopyu.com/techniques/ ... microscopy :

A unique aspect of photomicrography in stereomicroscopy is the ability to compose images that are stereo pairs, by employing specimens having significant three-dimensional spatial relationships among structural details. The first step is to photograph the specimen using the left eyepiece, followed by another photograph through the right eyepiece. An alternative procedure that can also be utilized with common main objective stereomicroscopes involves tilting the specimen on the horizontal (stage) axis by an angle of seven to eight degrees to the left of the microscope optical axis. After capturing a photomicrograph or digital image, the specimen is tilted an identical amount to the right of the optical axis and another photomicrograph (digital image) is recorded. This maneuver produces the same effect as taking two sequential photographs with a Greenough-style stereomicroscope.

This description still seems to me to suggest that the CMO camera port is looking straight down, where the Greenough eye paths are looking slanted from each side. Clearly there is something here that I don't understand, but I have enough other things in that category right now that I'm happy to just flag this one in my head and move on.

Thanks again,
--Rik

[Scarodactyl]

That's just suggesting you create a relative change in angle to simulate a pair within the same light path--that relationship should hold even with the light path off center.

[rjlittlefield]

That's just suggesting you create a relative change in angle to simulate a pair within the same light path--that relationship should hold even with the light path off center.

Maybe, but I'm not comfortable with that explanation because (a) it's always true so why bother to say it? and (b) the angles would not correspond to those of a Greenough design viewing the same subject from the original starting position.

Reading again, I note the comment:

click stop that permits the objective to be centered over just one of the two stereo optical paths ... eliminating the shift that would otherwise occur during a focus stack with a stereomicroscope

So now I'm thinking that by centering the objective on the camera path, the camera view is made to look straight down, where normally it would be looking from the side because of sharing an eye path. If that's the way it works, then the paragraph at microscopyu makes perfect sense to me except that it fails to mention the centering adjustment.

--Rik

[Stephen_De_Lisle]

Yes that paragraph from microscopyU is a little confusing for a couple of reasons; it would also be possible to obtain a stereo pair with a CMO scope by photographing through each eyepiece separately, as they suggest to do with a Greenough design, or by switching the optical path used by the camera port if that were possible (it is not on my scope, as the trinocular head uses only the right optical path for the camera port, with no option to switch). Further up in the article they do mention the objective centering feature of some CMO scopes, but in the context of eliminating chromatic aberration:

Some CMO stereomicroscope designs have made this a non-issue by providing the facility to offset the large central objective, positioning it on the axis of either the left or right side channel.

By centering the objective over the photographic optical path (the "right side channel" in this case), you are indeed making the camera (and the view through the right eyepiece) look straight down on the specimen. On the SZX16 with both the .8x and 2x objectives I have, it is actually possible to still use both of the oculars at mid to higher zoom settings, but at the lowest zoom settings the image through the left eyepiece significantly obscured when the objective is positioned in this way. So it is a compromise solution to make a stereomicroscope a bit more suited for photography.

[rjlittlefield]

Excellent -- thanks for the confirmation and further information.

--Rik