Wow - what kind of rail are you using to reach ~250 nm steps? That is closer to linear servo territory. You can get step sizes almost that size with simple, cheap off-the-shelf microscope focusing block driven by the cheap WeMacro MicroMate. This is what I do, depending of the microscope focus bloc...

I am a little surprised at the low NA. .. ... I am surprised that the NA would go backwards as technology advances. Well, what matters is resolution, not NA itself. The former generation with immersion optics had 1.35 NA and lower resolution, the key as you well know is the shorter wavelength, and ...

Don't forget to put anti-reflection flocking inside to avoid glare

As others said this is a very nice microscope stand. But beware: the main part of a microscope is the objective(s). The BH is designed to work with DIN objectives (45mm parfocal and 160mm tube corrected). In your picture I see what seems a Olympus 160 objective together with a Zeiss infinite correct...

Very nice image, I love SEM (and have no access to one of them) They were the typical purple and white urchin color before sample prep. Still trying to figure out how to add the color back in... I would try the following approach (just a not proven idea): after setting up the sample but before metal...

Just to point that the term tube lens in our context refers to the lens itself (in your case the Raynox) and not to the tube that contains it. A is the distance that focus the tube lens alone (without objective) to infinite. With low magnification infinite objectives you can play with it to some ext...

There are also economical, extremely good 5x and 10x monochromatic "objectives" with high NA (greater than 0.35 in many cases), zero distortion, perfectly flat fields, and enormous image circles. These are among the best optics in existence, as long as you use the right wavelength of light. They ar...

Well, any microscope is monochromatic if you use monochromatic light.

A green filter has been a standard accesory with most new microscopes for long time for the very same reason you suggest

Excellent tests again, thanks for posting them.

Note: PM sent

Ray, thank you!

Oil darkfield condensers are crazy expensive. Dry ones are even rarer. :oops: Zeiss dedicated dark field condensers (two dry models and one oil "ultra condenser") are both excellent and relatively abundant at the used market. You would need to make or order a dovetail adapter, Charles Krebs did it ...

... The one drawback I found to the Pentax bellows was the focus rail clamp is the weak point in the system, and it caused me a lot of trouble with flexibility and slow recovery times to external vibration. In my own system today I have eliminated the clamp and mounted two focus rail X extrusions t...

I use a YN565EX and a Canon 7D, a different but comparable system. After some attempts I got it working as slave (I don't remember the settings) but anyway I found much more convenient a hot shoe cord exactly as suggested by Rik. ETTL-2 is very useful in general photography but I find that manual mu...

...it is impossible to get fluorescence of a shorter wavelength than the exitation wavelength

It was impossible until the invention of two-photon and other multi-photon fluorescence techniques, BTW not available for us mere mortals

Nice macroscape While chlorophyll fluoresces red, many leaves fluoresce light blue, especially on their top surfaces. I think this is some kind of protective material, perhaps a UV-blocking layer to protect the leaf. Cutine, suberine and some waxes produce this kind of fluorescence, so you're right....