Hello all,
I have been struggling with the problem of low image quality for a very long time - basically the lack of sharpness when using 10x and 20x (mitutoyo) lenses
As a Tube Lens I use 40-150 2.8 PRO + two intermediate rings to reduce vinification.
with mitutoyo 5x it works great - which is confirmed by the photo below:
mitutoyo 5x by Radoslaw, on Flickr
however, the matter changes dramatically, after connecting, for example, mitutoyo 10x or 20x, there is no question of any micrometer where the area is sharp.
It looks as if the image area is not completely in focus ...
I figured the tube lens might be the problem, so I bought a 70-300 lens to have the required 200mm focal length - unfortunately the problem is the same.
here are photos from 10x mitutoyo:
mitutoyo 10x by Radoslaw, on Flickr
and 20x mitutoyo
Mitutoyo 20x by Radoslaw, on Flickr
My setup looks like that:
20220701_230830 by Radoslaw, on Flickr
20220608_061110 by Radoslaw, on Flickr
The exact specification of the set is:
Olympus OM-1 + 2 adapter rings (approx. 20mm) + 40-150 2.8 PRO
The lenses are attached with an adapter (which has been flocked out)
I wonder if, for example, the reason for the lack of focus is the need to keep some distance between the front element of the objective (tube lens) and the microscope objective.
My second theory, is there too much F-stop number due to the use of such a lens and in a set with e.g. mitutoyo 10x
I am begging you for help, I am already powerless in this matter.
Kind regards,
Image sharpness problem - Mitutoyo 10x and 20x
Moderators: rjlittlefield, ChrisR, Chris S., Pau
Re: Image sharpness problem - Mitutoyo 10x and 20x
Hi Radek,
Well, the photo taken with the Mitu-10 looks great.
Could you please give the full name and parameters of your Mitu-20x (it looks like NIR)?
Best, ADi
Well, the photo taken with the Mitu-10 looks great.
Could you please give the full name and parameters of your Mitu-20x (it looks like NIR)?
Best, ADi
Last edited by Adalbert on Wed Jul 06, 2022 8:46 am, edited 1 time in total.
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Re: Image sharpness problem - Mitutoyo 10x and 20x
First, that is an NIR LCD Plan Apo 20x, not an M Plan Apo 20x. Where did you even get that. The LCD specification means it expects some cover glass between it and its subject (of 0.7mm in this case). If you want to swap for a normal mitutoyo m plan apo 20x I have one in surplus and have wanted to try the LCD variation. That said I am not sure what the relative value is on the used market--new they cost more than a normal m plan apo but there is less demand for used copies. Point being you might also have some luck selling it and buying a normal 20x. Without the cover glass you'll get spherical aberrations which will affect contrast.
Re: Image sharpness problem - Mitutoyo 10x and 20x
that i didint know - i was thought that the NIR working same like normal lens
well i pay almost 1k Euro for that - if u want we can trade if You are in Europe
well i pay almost 1k Euro for that - if u want we can trade if You are in Europe
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Re: Image sharpness problem - Mitutoyo 10x and 20x
I'm in the US which would be less ideal unfortunately. I'd still be game if you want to try but it might be easier for you to just resell it. The NIR part isn't necessarily a problem (though it might not be as well corrected in the visible range, not much testing done on these), but the cover glass correction will definitely cause trouble. My interest is because most of my subjects are inside gems so the correction can help me.
Re: Image sharpness problem - Mitutoyo 10x and 20x
so here is another testing of mitutoyo 10x
i was using two lenses
olympus 70-300
olympus 40-150 2.8 Pro
here are result:
1. 70-300 @ 200mm - full size
in my opinion sharpness is very poor
70-300-@200mm-mitu by Radoslaw, on Flickr
2.
same lens, same picture just 50% cropped
70-300-@200mm-50%-crop--mitu by Radoslaw, on Flickr
3.
here is 40-150 pro - full size
slightly better but still in my opinion not as good i was observe picture from other people
40-150-pro-mitu-fs by Radoslaw, on Flickr
4.
same picture but cropped
40-150-pro-70%-croap by Radoslaw, on Flickr
Any idea what i should check ?
i was using two lenses
olympus 70-300
olympus 40-150 2.8 Pro
here are result:
1. 70-300 @ 200mm - full size
in my opinion sharpness is very poor
70-300-@200mm-mitu by Radoslaw, on Flickr
2.
same lens, same picture just 50% cropped
70-300-@200mm-50%-crop--mitu by Radoslaw, on Flickr
3.
here is 40-150 pro - full size
slightly better but still in my opinion not as good i was observe picture from other people
40-150-pro-mitu-fs by Radoslaw, on Flickr
4.
same picture but cropped
40-150-pro-70%-croap by Radoslaw, on Flickr
Any idea what i should check ?
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Re: Image sharpness problem - Mitutoyo 10x and 20x
A difference in sharpness between 5X and 10X will not be due to the tube lens. Both objectives make the same demands on the tube lens, and will run at the same effective aperture.
The 10X objective will be twice as sensitive to any vibration in the system, but your images do not look to me like they are softened by motion blurring.
That leaves a difference between the objectives.
One painful possibility is that the 10X objective has been slightly damaged, so that its lens elements are no longer perfectly aligned. This is quite common with used Mitutoyo objectives. See for example my story at https://www.photomacrography.net/forum/ ... hp?t=20594 .
As a practical matter, Mitutoyo M Plan Apo objectives cannot be repaired; the tolerances are very tight and even Mitutoyo cannot be paid enough to fix them.
If the objective is damaged in this way, then the practical choice is between living with the softness or replacing the objective. For the sample images that you have posted, significant improvement can be made by digital sharpening.
--Rik
The 10X objective will be twice as sensitive to any vibration in the system, but your images do not look to me like they are softened by motion blurring.
That leaves a difference between the objectives.
One painful possibility is that the 10X objective has been slightly damaged, so that its lens elements are no longer perfectly aligned. This is quite common with used Mitutoyo objectives. See for example my story at https://www.photomacrography.net/forum/ ... hp?t=20594 .
As a practical matter, Mitutoyo M Plan Apo objectives cannot be repaired; the tolerances are very tight and even Mitutoyo cannot be paid enough to fix them.
If the objective is damaged in this way, then the practical choice is between living with the softness or replacing the objective. For the sample images that you have posted, significant improvement can be made by digital sharpening.
--Rik
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Re: Image sharpness problem - Mitutoyo 10x and 20x
There's one factor that the 5x wouldn't mind but the 10x might, which is whether your tube lens is focused at infinity. Did you say you had two intermediate rings?
Re: Image sharpness problem - Mitutoyo 10x and 20x
yes i was adding two extension tubes between body and lens, to reduce vignetting
Re: Image sharpness problem - Mitutoyo 10x and 20x
You could try 10x without the extensions for testing purposes. If the center is then sharp, you know the problem. And if that is the problem, the 20x will be hit even worse regardless of the version.