Basis question about infinite objectives compatibility

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clipi
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Joined: Sat May 19, 2018 11:13 am

Basis question about infinite objectives compatibility

#1 Post by clipi » Sat Nov 10, 2018 2:07 pm

Hello,

For what I read so far I was sure that one can not combine Infinite objective with standard 160 objectives, but I have
seen several microscopes on ebay which are sold with a mixture of lenses. Such as this one combining expensive olympus infinite with
some Leitz plan

https://www.ebay.com/itm/LEICA-LABORLUX ... 4902.l9144

I have a Leitz laborlux D micro so I would realy would like to know if other people combined lenses (standar, plan, infinite) whitout problems.
Thanks

Hobbyst46
Posts: 4277
Joined: Mon Aug 21, 2017 9:02 pm

Re: Basis question about infinite objectives compatibility

#2 Post by Hobbyst46 » Sat Nov 10, 2018 2:37 pm

clipi wrote:Hello,

For what I read so far I was sure that one can not combine Infinite objective with standard 160 objectives, but I have
seen several microscopes on ebay which are sold with a mixture of lenses. Such as this one combining expensive olympus infinite with
some Leitz plan

https://www.ebay.com/itm/LEICA-LABORLUX ... 4902.l9144

I have a Leitz laborlux D micro so I would realy would like to know if other people combined lenses (standar, plan, infinite) whitout problems.
Thanks
I would inquire the seller about the optical output, especially the photographic output of that mixing in the link you cite. From my experience, even for the same finite optics, Olympus SPlan objectives yield CA with Zeiss eyepieces. I suspect the same would happen with Leitz Periplan. Adding the difference of IC vs finite tube length would (IMO) make it worse.
Also, the listed MSPlan objectives are metallurgical objectives, so their thread might differ from RMS. I would check with the seller about this combination of objectives on the same turret, are they fitted by means of thread adapter rings etc.
Since the seller declares that the microscope works perfectly, it is not a huge risk however.

PeteM
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Location: N. California

Re: Basis question about infinite objectives compatibility

#3 Post by PeteM » Sat Nov 10, 2018 6:15 pm

Mixing finite and infinite objectives is usually a sign of either an ignorant or a deceptive seller. You can sometimes get an image, but it's usually poor and the objectives will almost never be parfocal.

Mixing different brand finite objectives can work; especially if they are newer versions where all or most corrections are in the objective rather than the eyepieces.

Mixing different infinite objectives can also work. Best if they have the same tube length to the tube/telon lens and with corrections in the objectives rather than some in the tube lens.

You can also usually replace all the 160mm finite objectives with 160mm tube length finite objectives of another brand, change to the proper correcting eyepieces, and perhaps shim them to pick up the image properly -- and get good images. This makes the most sense on a microscope with replaceable objective turrets -- you can easily swap in another set. As an example, I have a set of Zeiss NeoFluar phase contrast objectives on an Olympus turret that works well. In this rare case, even the Olympus phase rings are quite close.

To add: I just took a look at the Ebay listing. Those three Olympus MSPlan objectives are meant to go through an Olympus infinity conversion head; usually with a choice of transmitted and reflected light. And they aren't a match for the other two Leitz finite objectives on the turret.

Especially at higher magnifications (e.g. 40x), the MSPlan lens, even on the right scope, won't work well with a slide and coverslip. It's meant for no coverslip.

The microscope is also over-priced in my opinion (e.g. not "the best deal on Ebay"), and one eyepiece so smeared and dirty it doesn't speak especially well to the seller's "works perfectly" claim. How this seller has managed a top Ebay rating is a mystery to me -- but it doesn't look like he/she sells many microscopes.

Leitz did a fair amount of correction in the eyepieces, and Leitz finite objectives are commonly available fairly affordably, so I'd be inclined to stick with those. Ideally with finite (160mm) markings and (if using slides) a .17 cover slip designation. You can even use some older short barrel Leitz objectives on "Plezy" adapters and (after reading Leitz literature on the subject) some of the old 170mm tube objectives -- though those workarounds probably only make sense if you find something like a Leitz 100x apochromat for $50.

If you want no cover-slip (metallurgical, epi, etc.) objectives, Leitz did make a setup somewhat similar to Olympus, allowing their own "infinity" 0 cover slip objectives to be used (with an additional head containing a correction lens) on stands like yours.

einman
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Joined: Tue Feb 24, 2015 1:03 am

Re: Basis question about infinite objectives compatibility

#4 Post by einman » Sat Nov 10, 2018 8:22 pm

An E-bay seller saying a scope works perfectly and/or says it is refurbished when it is obvious they know nothing about scopes is risky. I have purchased scopes that were supposed to be "refurbished" and were covered in dust etc. It was obvious nothing had been done to the scope. I have also seen comments that the scope "works perfectly" when it was missing eyepieces and/or had no objectives. Many scope sellers simply picked up the scope in a surplus sale and list it.


You can also observe the wide span of pricing for essentially the same scope. I have a Leitz Diaplan listed which is refurbished and does work perfectly up against inferior Diaplans listing for 2 to 7 times the price!!

Shop around ask lots of questions and don't hesitate to post the listing here and let members use their knowledge and experience to critique the scope.

MichaelBrock
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Joined: Tue Aug 22, 2017 4:47 pm

Re: Basis question about infinite objectives compatibility

#5 Post by MichaelBrock » Sat Nov 10, 2018 8:54 pm

einman, what is your Ebay user name? I'd like to keep an eye on your auctions for things I might "need".

einman
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Re: Basis question about infinite objectives compatibility

#6 Post by einman » Sun Nov 11, 2018 1:22 am

MichaelBrock wrote:einman, what is your Ebay user name? I'd like to keep an eye on your auctions for things I might "need".

einman2001

I list scopes and then if no immediate interest I withdraw it. Most of the time I am selling to make room in my lab. If I had the space I would probably never sell. The Diaplan I have currently listed is a reluctant offer but I just do not have enough space to store them all.

clipi
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Joined: Sat May 19, 2018 11:13 am

Re: Basis question about infinite objectives compatibility

#7 Post by clipi » Sun Nov 11, 2018 5:47 pm

Thanks, very clear explanations!!

apochronaut
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Re: Basis question about infinite objectives compatibility

#8 Post by apochronaut » Sun Nov 11, 2018 10:28 pm

Specifically, regarding the compatibility of the objectives in the microscope, they are in fact likely, all infinity corrected. Leitz was making oo/0 objectives before they adopted the AO/Reichert system as their "Delta" optics, so those two Leitz as epi objectives, would more than likely work o.k. with the Olympus no cover. The tube length difference would not be enough to cause too much magnification difference.

The microscope itself is way over priced based on it's level of completeness and the condition.

PeteM
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Location: N. California

Re: Basis question about infinite objectives compatibility

#9 Post by PeteM » Sun Nov 11, 2018 11:34 pm

A problem, even if they're all infinity designs of different tube lengths, is likely the head. It looks to be a Leitz finite model (I believe the infinity versions have sort of a bevel shaped black surround) with Leitz-finite-correcting eyepieces.

The Leitz infinity optics I've seen on stands of the Laborlux D, S, 11, 12 era required either an infinite head or an intermediate piece with a correction lens (and usually an epi and possibly BF/DF illuminator).

One of these days I'll have to try Olympus 180mm infinity and/or Leica 200mm (?) infinity objectives on a Leica finite stand . . . I'm inclined to think they'll need at least an intermediate correction lens to provide crisp and parfocal images.

Hobbyst46
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Joined: Mon Aug 21, 2017 9:02 pm

Re: Basis question about infinite objectives compatibility

#10 Post by Hobbyst46 » Mon Nov 12, 2018 1:24 pm

PeteM wrote:A problem, even if they're all infinity designs of different tube lengths, is likely the head. It looks to be a Leitz finite model (I believe the infinity versions have sort of a bevel shaped black surround) with Leitz-finite-correcting eyepieces...
apochronaut wrote:Specifically, regarding the compatibility of the objectives in the microscope, they are in fact likely, all infinity corrected. Leitz was making oo/0 objectives before they adopted the AO/Reichert system as their "Delta" optics, so those two Leitz as epi objectives, would more than likely work o.k. with the Olympus no cover. The tube length difference would not be enough to cause too much magnification difference.
Here are the objective specs stated by the seller:
OLYMPUS M SPLAN 5 0,13 f=180 IC 5
LEITZ WETZLAR PLAN 4/0.10 160/-
LEITZ WETZLAR PLAN 10/0.25

OLYMPUS M SPLAN 20 0,46 f=180 IC 20
OLYMPUS ULWD M SPLAN 50 0,55 f=180 IC 50

I wonder - can the Leitz 4X and 10X be infinity corrected? assuming of course that the seller accurately cited the marks on the objective ?

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