What affects the image produced from two different microscopes?

[jb89]

At school we have Meiji monocular scopes and some Chinese scopes with plan non-pol objectives that produce really nice images but we have a Leica DM EP that produces images that look like my Leits SM-LUX-POL.

This is an image from my SM-LUX-POL.

Pic #1.jpg (40.62 KiB) Viewed 3590 times

And this is from one of the chinese scopes.

Pic #2.jpg (45.61 KiB) Viewed 3590 times

I was wondering what makes them look so different(besides being different samples/magnification), is it depth of field, specimen preparation, objectives?

Thanks!

[MicroBob]

The images don't allow a comparison. But if you have the impression, that your microscope's image is not allright, they you should check the optics for damages or dirt. Look at the front and back lens with phase telescope and stereo microscope. Shine a flashlight though the tube and check whether it is hazy.

Bob

[wporter]

You've sorta answered your own question....

Not to harsh on the inquiry, because it's a good one, and the images are good, too, but you must decrease the number of variables. That is, image the same subject, at the same magnification, polarizer angle, lighting (as much as possible), etc. You cannot legitimately say "besides being different blah blah..."

In this case, it's hard to tell if, under identical setups, with the same subject, whether there would be any big difference at all. Especially with samples under crossed polarizers, where a slight rotation of the polarizer or analyzer can make a huge difference.

[PeteM]

What wporter said. Once you managed to get the same petrographic sample, at the same magnification, with the same polarization angles then some differences might be:

- quality and color temperature of the illumination system - even voltage differences in halogen
- quality (extinction) and inherent color of the polarizers
- setting of the condenser illumination - perfect Kohler, field and condenser iris settings, condenser height etc.

There are significant differences between various objectives in terms of resolution, color accuracy, and contrast (fewer internal reflections). However these are not so readily seen with polarized mineral sections - at least to my eye.

One also notes, from the backgrounds, that the camera exposure is better set for black with the Chinese scope.

[Scarodactyl]

Better optics overall do make a big difference. When I borrowed my advisor's petro microscope during my masters work I could immediately tell it was way better than the student grade stuff I'd used before, and that was before I was super into microscopes (always liked them but it wasn't a focus). I wish I knew the specs on it, all I remember was it was an Olympus from the 80s so probably in thr BH family.

[jb89]

The images don't allow a comparison. But if you have the impression, that your microscope's image is not allright, they you should check the optics for damages or dirt. Look at the front and back lens with phase telescope and stereo microscope. Shine a flashlight though the tube and check whether it is hazy.

Bob

I didn't suspect anything was wrong with my scope but I will keep that in mind, might be worth looking just for peace of mind and to make sure I am doing my cleanings and maintenance well enough.

You've sorta answered your own question....

Not to harsh on the inquiry, because it's a good one, and the images are good, too, but you must decrease the number of variables. That is, image the same subject, at the same magnification, polarizer angle, lighting (as much as possible), etc. You cannot legitimately say "besides being different blah blah..."

In this case, it's hard to tell if, under identical setups, with the same subject, whether there would be any big difference at all. Especially with samples under crossed polarizers, where a slight rotation of the polarizer or analyzer can make a huge difference.

I totally see what you mean, I will borrow that sample from school or get pictures from two scopes in the same magnification/polarization sometime this week.

What wporter said. Once you managed to get the same petrographic sample, at the same magnification, with the same polarization angles then some differences might be:

- quality and color temperature of the illumination system - even voltage differences in halogen
- quality (extinction) and inherent color of the polarizers
- setting of the condenser illumination - perfect Kohler, field and condenser iris settings, condenser height etc.

There are significant differences between various objectives in terms of resolution, color accuracy, and contrast (fewer internal reflections). However these are not so readily seen with polarized mineral sections - at least to my eye.

One also notes, from the backgrounds, that the camera exposure is better set for black with the Chinese scope.

PeteM, I think this is more what I was curious about, I used my phone camera for both pictures and the settings were on "auto", with that they may have completely different photo settings.

I am not sure I 100% have a strong understanding of Kohler illumination and adjustments with irises and condenser height, it's not something we are taught in class and we're kind of just expected to figure out how to get a usable image. I will have to look if I can find any quick reads or video tutorials on this.
Edit: I googled it and immediately found this, basically the same way I've been doing it but it's nice to know the technical terms and follow the recommended steps https://www.zeiss.com/microscopy/us/sol ... ation.html

Better optics overall do make a big difference. When I borrowed my advisor's petro microscope during my masters work I could immediately tell it was way better than the student grade stuff I'd used before, and that was before I was super into microscopes (always liked them but it wasn't a focus). I wish I knew the specs on it, all I remember was it was an Olympus from the 80s so probably in thr BH family.

That's what lead me to the question, I would have expected my Leitz sm-lux-pol and my professors Leica DM EP both with pol/fluorite objectives to provide much better images than the chinese scope that only has plan non-pol objectives but in this case they didn't.

I think the next step is testing the same sample in uniform conditions as you've all suggested, I will post my results as soon as possible!