Question about a Zeiss Universal I have my eye on - expert opinion anyone?

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billben74
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Question about a Zeiss Universal I have my eye on - expert opinion anyone?

#1 Post by billben74 » Sat Nov 04, 2017 8:44 pm

I'm interested in Zeiss Universal on ebay. At some risk of inviting cometition for the auction ;) I want to ask a question....
https://www.ebay.co.uk/itm/zeiss-univer ... 2100162075?
I don't know that much about 160mm systems having a modern chinese job from Brunel microscopes.
My objectives are corrected.
The chap selling the Universal seems on the ball and has fabricated a nice looking photorelay system.
I think I know that on Olympus BHS etc that you have to get an olympus relay tube to get proper colour correction but I'm not sure if this is true for a Zeiss Universal?

I know there are some Zeiss experts around. Anyone fancy putting forward an educated opinion on likely hood that his relay system is going to be fully corrected?

I'll probably get out bid but I am druelling over this microscope as I really want epi/- epi fluorescence options in addition to diascopic light
(and possible DIC in future world where I have more money ;)

photomicro
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Re: Question about a Zeiss Universal I have my eye on - expert opinion anyone?

#2 Post by photomicro » Sat Nov 04, 2017 9:47 pm

I have had a quick look. All he is referring to in terms of the self constructed camera mount is the physical link, as he/she doesn't say what is inside optically. What should fit in there depends of the camera is going to be mounted as an 'focal' system, using the camera lens as part of it, or just a camera body. In either case, there would be an eyepiece used. This isn't referred to.

The Zeiss 160 objectives require some sort of compensation in the eyepiece/relay system, as you have probably realised.

This is a Universal model 2 BTW.

Hope this helps.

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billben74
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Re: Question about a Zeiss Universal I have my eye on - expert opinion anyone?

#3 Post by billben74 » Sat Nov 04, 2017 10:29 pm

Thanks, that is useful.
I have messaged the seller something that might precipitate an answer to if he has anything inside.

Charles
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Re: Question about a Zeiss Universal I have my eye on - expert opinion anyone?

#4 Post by Charles » Sun Nov 05, 2017 12:55 am

That looks like a very nice system with the Zeiss RS III Epi-fluoro and a phase condenser (although none of the objectives are phase but the option is nice and phase objectives are readily available). You have a lot of options with this Zeiss Universal. I believe this is a Universal III system because the focus knobs are plastic and the Zeiss brand is imprinted in ink at the front. The Universal II have metal focus knobs and a metal Zeiss plate instead of the ink print. No matter, what Photomicro says is correct in that Zeiss objectives require Zeiss compensating eyepieces and it depends on the optics in the photo tube. If used without the camera lense, you would need a Zeiss photo eyepiece in the photo tube...KPL or KPL-S but this photo tube looks like it connects directly to the camera lens.

Hobbyst46
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Re: Question about a Zeiss Universal I have my eye on - expert opinion anyone?

#5 Post by Hobbyst46 » Sun Nov 05, 2017 8:06 pm

For epi-fluorescence you need an epi-illuminator, which usuallymust be a powerful light source like a 50w mercury or xenon lamp, and several combinations of excitation filter, beam splitter and emmision filter, where each combination selects the excitation and emmision wavelengths. I would verify ahead of the purchase of the microscope that such items are available for this model. I did not see them bundled with the microscope on ebay. A LED light source will provide you with a single wavelength usually. For excitation.

What's more, for UV excitation the objectives should be UV compatible, otherwise most of the excitation intensity is lost. The objectives in that bid may or may not fit from this point of view.

On the otger hand, I am not familiar with this model, so maybe that condenser does include the required optics.
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

Hobbyst46
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Re: Question about a Zeiss Universal I have my eye on - expert opinion anyone?

#6 Post by Hobbyst46 » Sun Nov 05, 2017 8:22 pm

Two more tips.
First, the intensity of the fluorescence is proportional to the intensity of the illumination, but the former is a million times weaker than the latter, so you really need powerful illumination.
Second, the easiest way to check that your setup is OK and the illumination is uniform across the field of view is to have a slide of flurophores. Like a coating of Rhodamine, or better still, fluorescent micro beads. This are multi-emmision and have a standard size like 3micron, 6, 10microns etc. Available from several suppliers. They are sold suspended in water or salt water and are very bright and uniform in size.
Good luck - hope did not overdo...
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

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Re: Question about a Zeiss Universal I have my eye on - expert opinion anyone?

#7 Post by Hobbyst46 » Sun Nov 05, 2017 8:42 pm

On a second thought, I looked again at the ebay item and at the Universal RS description on the net. It appears that the bid does not include an epi-illuminator at all. And indeed, like all other fluorescence microscope, one needs a high pressure mercury or xenon lamp. Zeiss originally ofered the option of a 100W halogen lamp for FITC, but that might be inadequote light intensity. A 10W LED not only provides only ond wavelength, but is also too weak, in my opinion, for fluorescence.
Only to keep in mind.
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

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billben74
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Re: Question about a Zeiss Universal I have my eye on - expert opinion anyone?

#8 Post by billben74 » Mon Nov 06, 2017 8:09 pm

All really useful.
I am interested in having regular episcopic as well as fluorescence.
I believe one could choose use the illuminator sold with the item as either episcopic or diascopic and that is fine for me at the moment.
Although I presently illuminate using reflected light using my home brew lighing arrangement a few subjects, I believe need direct episcopic illumination - notably highly metallic insects end up with a shadow under the lens and I am hoping that I can finally get the capacity to evenly illuminate these.

I don't mind having to build up to fluorescence, but at least the Universal gives me options in this direction.
My understanding was that Zeiss had decent options for flurescence illumination for the universal - that the Univesal was just that - Universal.

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Re: Question about a Zeiss Universal I have my eye on - expert opinion anyone?

#9 Post by Hobbyst46 » Mon Nov 06, 2017 8:27 pm

Yes, the Universal is designed for fluorescence. And the original Zeiss brochure of manual specify that the epi light source should be a 50-200 high pressure mercury lamp, or a 100W halogen just fir FITC. This molecule is not a part of nature - but an added stain. So if there is plenty of stain in the sample, the 100W might provide fluorescence. The fluorescent beads will shine even under that halogen. The trick of epi fluorescence is to illuminate the sample as strongly as possible but allow only the immensely weaker fluorescence to reah the eye or camera.
All the best.
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

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Re: Question about a Zeiss Universal I have my eye on - expert opinion anyone?

#10 Post by billben74 » Thu Nov 09, 2017 10:05 pm

Darn it. Got outbid. Ho Hum.
Still a Zeiss Universal still seems like a good option... maybe next time.

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