which 20x microscope optics to choose ?

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Chris S.
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Re: which 20x microscope optics to choose ?

Post by Chris S. »

Thanks, Pau, for mentioning the very good Olympus objectives.

I often forget to include them in discussions. I have no experience with them, and don't grasp which Olympus objectives work without corrective optics, and which ones do not. I've learned much of Nikon and Mitutoyo brands' alphabet soups, but not Olympus'.

If someone knowledgeable would write: "FAQ--which Olympus objectives are good for macro work, and which are not?" This would be useful.

There are some wonderful images, in our galleries, made with Olympus objectives.

--Chris S.

Scarodactyl
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Re: which 20x microscope optics to choose ?

Post by Scarodactyl »

There are only a few olympus infinity objectives that had eyepiece corrections, splans and dplans. They also have different styling from later uis/uis-2 objectives.

Chris S.
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Re: which 20x microscope optics to choose ?

Post by Chris S. »

Scarodactyl wrote:
Wed Mar 22, 2023 10:18 pm
There are only a few olympus infinity objectives that had eyepiece corrections, splans and dplans. They also have different styling from later uis/uis-2 objectives.
So--could you perhaps write a FAQ?

Alan Wood
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Re: which 20x microscope optics to choose ?

Post by Alan Wood »

The Olympus infinity-corrected objectives that require compensating eyepieces are from the BH-2 era.

Bright field (RMS): MA, MDPlan, MSPlan and MSPlanApo

Dark field (26 mm): Neo DPlan and Neo SPlan

As far as I know, all other Olympus infinity-corrected objectives are from the BX era and do not require compensating eyepieces.

Alan Wood

Scarodactyl
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Re: which 20x microscope optics to choose ?

Post by Scarodactyl »

Chris S. wrote:
Wed Mar 22, 2023 10:35 pm
Scarodactyl wrote:
Wed Mar 22, 2023 10:18 pm
There are only a few olympus infinity objectives that had eyepiece corrections, splans and dplans. They also have different styling from later uis/uis-2 objectives.
So--could you perhaps write a FAQ?
Sure, though I would certainly defer to Alan on this since he's the olympus expert. It would be a pretty short post either way.
Edit: I went ahead and posted a draft.
Last edited by Scarodactyl on Thu Mar 23, 2023 10:08 am, edited 1 time in total.

Pau
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Re: which 20x microscope optics to choose ?

Post by Pau »

Charles Krebs uses (or used) Olympus infinite MPLFLN UIS2 objectives in his DIY "macroscope" viewtopic.php?p=144389#p144389

Objectives briefly commented here http://www.photomacrography.net/forum/v ... 07#p113307
Pau

smugles
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Re: which 20x microscope optics to choose ?

Post by smugles »

hello Pau and thank you very much for your help too.
The images in your gallery are incredibly beautiful!

Indeed I would like to orient myself on this. But the price is not in my budget at all! However I'll note it in my list.

I read in the topic you gave me in link that the LU Plan has a notable axial CA. What does the term CA mean? I suppose an imbalance?

Now I think you all have oriented me very well. Also I will read all the posts and a few topics of the sort with a clear head. In my idea I will move towards infinite optics. I will exlure the Mitutoyo copies, look carefully at the real Mitutoyo and follow the sales.......

I really appreciated the quality of your answers, your availability. Thank you again for your insctuctive comments.
Eric

Pau
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Re: which 20x microscope optics to choose ?

Post by Pau »

You're welcome, Eric

Olympus UIS and UIS2 objectives usually are very expensive but, likely due to lower demand than Mitutoyo, with patience and/or luck they can be bought used for good prices (I got mine few years ago under $100 the 4X and for about $200 the 20X if I remember well)

CA = Chromatic Aberration
There are two main kinds of CA, take a look at: viewtopic.php?p=156506#p156506
rjlittlefield wrote:
Sun Nov 16, 2014 9:03 pm
First, recognize that there are two very different kinds of chromatic aberration.

One kind, called "lateral" or "transverse", occurs when the lens effectively has different magnifications for different colors, even though all colors focus in more or less the same plane. This form causes the classic bands of color around high contrast edges that happen to be oriented tangential to the optical axis.

The other kind, called "longitudinal" or "axial", occurs when the lens effectively has different focal lengths for different colors, so the colors focus in different planes. However, the magnification for each color may be identical in any particular plane. This form causes a very different appearance in which small dark features appear different colors when they are slightly in front or in back of focus, and in which their true colors may never appear at any focus.

Suppose you image dark tree branches against a bright sky. Then transverse CA will be visible only away from center and will manifest as colored bands around tangentially oriented branches. But axial CA will be visible everywhere, and will manifest as branches that typically look purplish or bluish. (You will of course have focused the green image because that's what your eye is most sensitive to. The dark branch will then be filled in with some combination of red and blue from the surrounding sky, depending on how badly those colors are defocused.)

--Rik
Be aware that the term "axial CA" sometimes is used wrongly referring to lateral CA.

Because axial CA mainly affects the out of focus areas, image focus stacking eliminates it very well
Pau

smugles
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Re: which 20x microscope optics to choose ?

Post by smugles »

ok thanks a lot.
A Have a question : with my 20xCF Plan 0.46 EPI WD 3.1- infinite ∞/0
It must be mounted on what length of lense tube? Because I try to stack the Willemite, it is difficult but just doable. (As a test I take the length of 125mm sensor to DCR250)
and how to know these lengths when they are not engraved on the barrel? By questioning the nikon site? Although these lenses are not designed for photography
Thanks
Last edited by smugles on Mon Mar 27, 2023 9:15 am, edited 1 time in total.

Scarodactyl
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Re: which 20x microscope optics to choose ?

Post by Scarodactyl »

All nikon infinity objectives use a 200mm tube lens to get their nominal magnification.

smugles
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Re: which 20x microscope optics to choose ?

Post by smugles »

ok thanks a lot

seta666
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Re: which 20x microscope optics to choose ?

Post by seta666 »

smugles wrote:
Mon Mar 27, 2023 9:01 am
ok thanks a lot.
A Have a question : with my 20xCF Plan 0.46 EPI WD 3.1- infinite ∞/0
It must be mounted on what length of lense tube? Because I try to stack the Willemite, it is difficult but just doable. (As a test I take the length of 125mm sensor to DCR250)
and how to know these lengths when they are not engraved on the barrel? By questioning the nikon site? Although these lenses are not designed for photography
Thanks
I have the BD version of that same lens and in my opinion it is a very good lens, WD on the BD version is perfectly fine. I own a few 20X lenses and all have its pros and cons, even the mitutoyo.

Scarodactyl
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Re: which 20x microscope optics to choose ?

Post by Scarodactyl »

Yeah, the mitutoyo 20x is imo best in class but you can get much sharper images if you can sacrifice some working distance, and the price on them has crept up while occasional deals have gotten more and more occasional.

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