Mitutoyo finescope fs100

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Sabatini
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Re: Mitutoyo finescope fs100

#31 Post by Sabatini » Mon Mar 30, 2020 6:12 pm

Missing filter
Missing filter
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Scarodactyl
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Re: Mitutoyo finescope fs100

#32 Post by Scarodactyl » Mon Mar 30, 2020 6:44 pm

It is likely missing part of the anti-reflex system. Light entering the scope is polarized so you can control internal reflections with an analyzer. If part of that is missing you could have nasty issues with internal reflections causing flare.
For most usage ourside of industrial examination the coaxial illuminator isn't the best option anyway. Oblique illumination will serve much better for excellent photos.

Hobbyst46
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Re: Mitutoyo finescope fs100

#33 Post by Hobbyst46 » Mon Mar 30, 2020 7:17 pm

Sabatini wrote:
Mon Mar 30, 2020 6:07 pm
I wanted to ask you to help me again with your suggestions.
As I have no experience with reflected light microscopes, I have no reference to compare with.
I notice that this microscope (in reflected light) produces images that are totally lacking in contrast, flat and of very poor quality...completely washed out and cloudy. Looking for the possible fault, I notice that there is a reflection of light that bounces off the back of the lens to the eyepieces when the light enters it. I also notice that the microscope has a filter missing right at the entrance of the reflected light. The filter can be moved with a lever that turns it 180 degrees or half a turn.
Now if only an explanation were possible that would help improve this. Since by placing two external lights on each side of the sample, the contrast is excellent and the colors very saturated...
Do I correctly understand that contrast is lacking in reflected light only ? that is if the only the epi-illuminator is on ?
I will try to guess. Good contrast depends upon the illumination. Supposing that your epi-illuminator is powerful enough, one still needs a condenser. The condenser in the epi-illumination setup is the objective itself. And Kohler conditions should be set. I believe that the two aperture irises that are visible in your epi-illuminator can be adjusted to set Kohler.
Better objectives that are optimized for epi-illumination are usually thicker than ordinary objectives and their thread is different, meaning that a separate nosepiece turret is needed, or alternatively the same nosepiece turret but with removable adapters to accommodate both different threads.
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

Sabatini
Posts: 106
Joined: Tue Nov 12, 2019 3:09 am

Re: Mitutoyo finescope fs100

#34 Post by Sabatini » Mon Mar 30, 2020 8:23 pm

Scarodactyl wrote:
Mon Mar 30, 2020 6:44 pm
It is likely missing part of the anti-reflex system. Light entering the scope is polarized so you can control internal reflections with an analyzer. If part of that is missing you could have nasty issues with internal reflections causing flare.
For most usage ourside of industrial examination the coaxial illuminator isn't the best option anyway. Oblique illumination will serve much better for excellent photos.
Your approach to the problem is very reasonable, the flares are very strongly manifested as you claim, some anti-reflective element is missing.
On the contrary when using oblique light the images are excellent with contrast and very saturated colors I'm going to use a polarizing filter and see what results I get.
Anyway the mitutoyo M plan apos objetives gave very nice optical results, I will make the adjustments to achieve an oblique illumination there will be no problem in it.I will keep on experimenting.
But in short, your explanation seems to me very accurate, thank you very much.

Sabatini
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Re: Mitutoyo finescope fs100

#35 Post by Sabatini » Mon Mar 30, 2020 8:28 pm

Deal with using this polarizer
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Sabatini
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Re: Mitutoyo finescope fs100

#36 Post by Sabatini » Mon Mar 30, 2020 8:36 pm

Hobbyst46
I will try to adjust the Kohler ilumination accurately as possible, if I see any improvement with this procedure I will comunícate it.
I'm grateful for your advice and recommendations.

Scarodactyl
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Re: Mitutoyo finescope fs100

#37 Post by Scarodactyl » Mon Mar 30, 2020 11:05 pm

Hobbyst46 wrote:
Mon Mar 30, 2020 7:17 pm
Better objectives that are optimized for epi-illumination are usually thicker than ordinary objectives and their thread is different, meaning that a separate nosepiece turret is needed, or alternatively the same nosepiece turret but with removable adapters to accommodate both different threads.
These are maybe the best long working distance epi objectives made by anyone, at least as an off-the-shelf product (there are a few clones that are comparable, and some specialty rarities like the qioptiq mag.x or mitutoyo's own hr objectives that are better). Their longer parfocal distance apparently allows them to fill a niche that the big four can't.

PeteM
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Re: Mitutoyo finescope fs100

#38 Post by PeteM » Tue Mar 31, 2020 12:52 am

One source for the lack of contrast you see could be field and aperture iris settings. I assume those are present and can be adjusted to reduce stray light.

Dust, fungus, fingerprints etc. to the extent any are remaining after your scrupulous cleaning (maybe that half mirror?) are another possibility.

A flat aspect is also pretty much the course for simple epi illumination. Your scope probably has an polarizer option (on edit: see that others have already covered much of this). MIght help on some subjects. Darkfield and DIC are two other common ways to get more of a 3D contrast.

Sabatini
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Re: Mitutoyo finescope fs100

#39 Post by Sabatini » Tue Mar 31, 2020 1:18 am

Scarodactyl wrote:
Mon Mar 30, 2020 11:05 pm
Hobbyst46 wrote:
Mon Mar 30, 2020 7:17 pm
Better objectives that are optimized for epi-illumination are usually thicker than ordinary objectives and their thread is different, meaning that a separate nosepiece turret is needed, or alternatively the same nosepiece turret but with removable adapters to accommodate both different threads.
These are maybe the best long working distance epi objectives made by anyone, at least as an off-the-shelf product (there are a few clones that are comparable, and some specialty rarities like the qioptiq mag.x or mitutoyo's own hr objectives that are better). Their longer parfocal distance apparently allows them to fill a niche that the big four can't.
In this specific case, the Mitutoyo fs100 finescope microscope, short working distances are not possible because of the limited coarse focusing distances, so I do not think it is possible to use objectives other than LWD.

PeteM
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Re: Mitutoyo finescope fs100

#40 Post by PeteM » Tue Mar 31, 2020 1:34 am

You can just add to the stage to bring other objectives into range?

Sabatini
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Re: Mitutoyo finescope fs100

#41 Post by Sabatini » Tue Mar 31, 2020 1:49 am

PeterM
To the best of my knowledge, I have tried various combinations of the field and aperture diaphragm, but I have not been able to improve the flare lights.
I will try to use some polarizing filters and analyzer, since the microscope was bought without any of them. That's probably the reason for this problem

Scarodactyl
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Re: Mitutoyo finescope fs100

#42 Post by Scarodactyl » Tue Mar 31, 2020 2:34 am

Typically I think there is a polarizer in the lamp house, and an analyzer at 90 degrees above the beamsplitter. This tends to eat stray reflections from what I understand. There may also be a rotatable quarter wave plate to control the effect depending on the design. I'm not an expert on this though.

Sabatini
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Re: Mitutoyo finescope fs100

#43 Post by Sabatini » Tue Mar 31, 2020 3:45 pm

PeteM wrote:
Tue Mar 31, 2020 1:34 am
You can just add to the stage to bring other objectives into range?
thanks. How could this improvement be done?

Sabatini
Posts: 106
Joined: Tue Nov 12, 2019 3:09 am

Re: Mitutoyo finescope fs100

#44 Post by Sabatini » Tue Mar 31, 2020 3:51 pm

Scarodactyl wrote:
Tue Mar 31, 2020 2:34 am
Typically I think there is a polarizer in the lamp house, and an analyzer at 90 degrees above the beamsplitter. This tends to eat stray reflections from what I understand. There may also be a rotatable quarter wave plate to control the effect depending on the design. I'm not an expert on this though.
thanks. very valuable instructions. Since I plan to experiment by this way, I'm going to try adjust the polarizers to the microscope... and see if the flares are eliminated.
All be in touch.

PeteM
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Re: Mitutoyo finescope fs100

#45 Post by PeteM » Tue Mar 31, 2020 5:16 pm

Sabatini wrote:
Tue Mar 31, 2020 3:45 pm
PeteM wrote:
Tue Mar 31, 2020 1:34 am
You can just add to the stage to bring other objectives into range?
thanks. How could this improvement be done?
I've used two approaches.

One is to permanently raise the stage by using longer screws and spacers - or to machine a sort of form-fitting spacer block.

The other is to build another removable stage on top if you want both working distances available. I've done this on things like a Nikon scope where I wanted both 210mm and 160 mm parfocal objectives to swap in and out.

Simplest in your case (I'm assuming you only need somethng like 10mm more height?) could be a rectangle of something like Delrin with a hole through it and a couple slide ciips attached. Of the thickness needed. Could mount it with the same holes as the existing slide carrier.

Sabatini
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Re: Mitutoyo finescope fs100

#46 Post by Sabatini » Tue Mar 31, 2020 8:28 pm

PeterM
Very good information.
A very interesting improvement.
So I could take advantage of the Mitutoyo's large field of vision, and objectives with higher magnification and cover slips.
The second suggestion seems to me to be the most practical to do it without having to modify it much.
Thanks.

Scarodactyl
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Re: Mitutoyo finescope fs100

#47 Post by Scarodactyl » Tue Mar 31, 2020 9:02 pm

One notable feature of mitutoyo objectives is their gigantic field coverage. They project an image with a 200mm tube lens that covers a full frame sensor. Other objective makers just don't do this (after all, 26.5mm is the widest FoV 10x eyepiece you can get from Nikon or Olympus) and you'd likely have a disappointing experience with either vignetting or bad edge correction (or both) using another brand. You'd also have to spend a fortune to get objectives that are in the same class as what you've got here.
This is a powerful, purpose-built machine. It's not going to be a great stand for traditional biological work, but it's a dream setup for reflected light work. I wouldn't try to modify it to accommodate other objectives or to look at cover slipped specimens. If you don't want to do reflected light work you could likely sell this baby off for a hefty price and get something pretty darned exceptional for looking at slides. If you want to do reflected light work it might be a good idea to pick up a 150w halogen light source with dual goosenecks for finely controlled oblique lighting (plus whatever diffusers you want to improvise), but otherwise you've already got a super-pro setup.

microb
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Re: Mitutoyo finescope fs100

#48 Post by microb » Wed Apr 01, 2020 12:39 am

Sabatini wrote:
Mon Mar 30, 2020 6:07 pm
Cordial greetings.
I notice that this microscope (in reflected light) produces images that are totally lacking in contrast, flat and of very poor quality...completely washed out and cloudy. Looking for the possible fault,...
... by placing two external lights on each side of the sample, the contrast is excellent and the colors very saturated,
If oblique lighting looks good, then the optical path is clear. So I don't know about the cloudy you mention. With old reflection microscope, the lamp bulb is many times faint dull and yellowish in color spectrum because they are always near end-of-life in the used e-bay market. I never bothered to replace the bulbs. I switched to LED. My experience is based on BHM Olympus microscopes and cleaning up and getting camera ready those epis.

You don't need the missing polarizer slide to fix the image.

I'm going to be building some polarizer 360 slides for AX and BX. In a few months assuming I get some parts and the mechanism working, I can get you one done with the finescope form factor. But that will be a while. I have an epi somewhere around here with the slide. I think it also has a center fuzzy circular blocker for darkfield. Nikon and Olympus had a ND filter with clear window glass around the perimeter. Mitutoyo used a black fuzzy light absorbing circular sticker on a glass window. It's been a while -- that darkfield might be on a separate slide. I can't find the epi right now. But I do remember Mitutoyo's darkfield fuzzy blocker, since that was unique.

Thanks,
Ted

microb
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Re: Mitutoyo finescope fs100

#49 Post by microb » Wed Apr 01, 2020 12:48 am

Sorry, went looking back at your pictures. Your epi doesn't have the rectangular slide openings I thought you would have. But it is a trinocular. Can you rig a camera to aim down the tube and take some test images? Don't worry about getting a perfect fitting adapter. Just something so that camera does fall off and get busted by accident. Even if there are aberrations, a camera can help here. Did you clean that beamsplitter?

Ted

Sabatini
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Re: Mitutoyo finescope fs100

#50 Post by Sabatini » Wed Apr 01, 2020 4:07 am

Scarodactyl wrote:
Tue Mar 31, 2020 9:02 pm
One notable feature of mitutoyo objectives is their gigantic field coverage. They project an image with a 200mm tube lens that covers a full frame sensor. Other objective makers just don't do this (after all, 26.5mm is the widest FoV 10x eyepiece you can get from Nikon or Olympus) and you'd likely have a disappointing experience with either vignetting or bad edge correction (or both) using another brand. You'd also have to spend a fortune to get objectives that are in the same class as what you've got here.
This is a powerful, purpose-built machine. It's not going to be a great stand for traditional biological work, but it's a dream setup for reflected light work. I wouldn't try to modify it to accommodate other objectives or to look at cover slipped specimens. If you don't want to do reflected light work you could likely sell this baby off for a hefty price and get something pretty darned exceptional for looking at slides. If you want to do reflected light work it might be a good idea to pick up a 150w halogen light source with dual goosenecks for finely controlled oblique lighting (plus whatever diffusers you want to improvise), but otherwise you've already got a super-pro setup.
Very grateful for this information, it updates me of the qualities and capacities of this microscope, for what I have been able to read these objectives Mitutoyo are very appreciated to make macro photography. Then these things catch you with more passion and Zaz you are already hooked on a project.
After the first tests I realized that when using external lamps or oblique light the behavior of the images is of an excellent sharpness and contrast ,I would dare to say that in subjects like the center of a flower a 3D effect is achieved, they are very satisfactory images.
I think I will continue experimenting since I find in this equipment a source of experience that I think I should take advantage of now.
I will take your suggestion of getting a more powerful light source ,150w.
I will be in touch.

Sabatini
Posts: 106
Joined: Tue Nov 12, 2019 3:09 am

Re: Mitutoyo finescope fs100

#51 Post by Sabatini » Wed Apr 01, 2020 4:32 am

microb wrote:
Wed Apr 01, 2020 12:48 am
Sorry, went looking back at your pictures. Your epi doesn't have the rectangular slide openings I thought you would have. But it is a trinocular. Can you rig a camera to aim down the tube and take some test images? Don't worry about getting a perfect fitting adapter. Just something so that camera does fall off and get busted by accident. Even if there are aberrations, a camera can help here. Did you clean that beamsplitter?

Ted
Thank you very much for your kind offers.
I would be more than happy to share any such deal with you sir.
I will be very diligent in taking these photos and making them available to your knowledge and see where the possible flaw may be.
As I explained , is a reflected light that does not allow for adequate contrast.
I want to clarify with regard to the procedure of putting a polarizing filter and analyzer ...I quote microb - "You don't need the missing polarizer slide to fix the image."
Your assessment is correct, because I've tried a thousand ways and I didn't get a positive result at all.
The beansplit was cleaned and the optics in general were cleaned, in that, I have a little bit of dexterity and I think that there was no major damage when performing it, on the contrary the impurities were removed as best as possible.
Thank you.

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