Infinity vs 160

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Melifluonze
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Joined: Fri Nov 03, 2017 9:50 pm

Infinity vs 160

Post by Melifluonze »

A beginner question... maybe?

I have both an Olympus AH2 Vanox-T and an AHBT3 scope. I've played with them a little bit and the frames are fairly identical, or look to be so. The nosepieces/illuminators are interchangeable.

I've noticed that the objectives for the AH2, specifically for metalurgical work are infinity objectives (MSPLAN, NEO, etc), and the objectives for the AHBT3 are 160 objectives.

I thought that the path from objective to eyepiece (and correction?) determined whether you could utilize 160 or infinity objectives, yet these two scopes have the same optical path inside the frame and they can use both types? Or is it the nosepiece/illuminator that establishes the difference?

The Vanox-T shows the AH2-RLA or AH2-MA illuminator, and the AHBT3 shows the AH3-6RE and AH3-RFCA. Is this where the "magic" is? Does this mean that the infinite objectives used for metalurgical work (MSPLAN, NEO MSPLAN, etc.) cannot be used on the AH3 nosepieces for transmission? Does it mean that the 160 objectives cannot be used in the AH2 illuminators for transmissive (vertical?) observation? And does that mean that I can keep the MSPLAN/NEO MSPLAN objectives on the AH2 illuminators and the 160 objectives on the AH3 illuminator/nosepieces?

The odd thing then is that the AH3-RFCA is called a Reflected Light Fluorescence Vertical Illuminator, so then one should be able to use the MSPLAN/NEO MSPLAN objectives with it, correct? I'm missing something here, I think... I thought you had to have an "M" type objective to do reflective work... Is Fluorescence different somehow?

How can the SPLAN objectives be used for reflected fluorescence... Yup, I don't understand! :roll:

Somewhat confused... Thanks for any help!
Crazy Vanox AH2/3 Nut!

Pau
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Post by Pau »

The difference is in the optics inside the objective-eyepiece path that is NOT identical
- The metallurgical version has a 180mm tube lens to converge the infinite (parallel) light rays, likely placed at the epiilluminator upper side or at the head lower side.
- The biological 160mm corrected almost for sure has a telan lens system: a telan lens that transform the converging rays from the objective to parallel rays creating an infinite space before the fluorescence epiilluminator and a tube lens over it

This sounds weird and it is but it's due to historical reasons, nowadays all high end and most mid range microscopes use the infinite system but at that time before infinite was the standard things were mixed: for example Zeiss used 160 objectives in all microscopes but the Axiomat, Nikon used 210 objectives for metallurgical avoiding the telan lens while Olympus and Leitz used infinite for metallurgical, AO implemented infinite also for biologicals...and this is not at all the whole story.

I don't know the details of your microscopes and their crossed compatibility. With my simpler Zeiss Standards I can use infinite objectives removing the telan lens of the epifluorescence illuminator or intermediate piece but at reduced magnification due to the tube lens FL

If you use infinites in a 160 system or vice-versa you could get decent results with low NA ones but the image will be clearly degraded with high NA objectives due to spherical aberration
Pau

Melifluonze
Posts: 4
Joined: Fri Nov 03, 2017 9:50 pm

Post by Melifluonze »

Thanks for the reply!

The two scopes look identical, but there may be optics in the frame that do what you say. I have a couple of these that UPS dropped, so I'll probably take them apart to see if there are differences. (UPS actually cracked the cast frames of the scopes, but that's a story for another day!)

I suppose this means that I should be able to use infinite objectives on the metallurgical scope for transmittance viewing by adding the condenser components to the base. It looks like the illumination is present and the mounting system is identical.

I'm reading that all infinite objectives are not the same... that there's correction required for some. Interesting.
Crazy Vanox AH2/3 Nut!

Alan Wood
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Post by Alan Wood »

I am not a Vanox expert, but I think:

The AH2-MA brightfield vertical illuminator is for use with MSPlan infinity objectives.

The AH2-RLA brightfield/darkfield vertical illuminator is for use with Neo SPlan infinity objectives.

The AH2-MA and AH2-RLA probably include the 180mm tube lens.

The AH3-6RE is for 160mm objectives and does not include a tube lens.

The AH3-RFCA is also for 160mm objectives.

There are some Vanox documents here with more information:
http://www.alanwood.net/photography/oly ... html#vanox

Alan Wood

Melifluonze
Posts: 4
Joined: Fri Nov 03, 2017 9:50 pm

Post by Melifluonze »

Thank you, Alan,

And thank you for a wonderful website! Without your site the Vanox scopes would be more difficult to learn about!
Crazy Vanox AH2/3 Nut!

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