Weekend with New 'Scopes

[JGardner]

I just spent some quality time over the weekend with my two new microscopes and thought I'd share my experiences with others on the beginner's corner...

After deciding to get back into microscopy after a 35 year absence, I bought a well-used Leitz Orthoplan and Zeiss Universal on eBay. Both arrived without any shipping damage, but both had numerous issues that needed to be addressed. Part of my task this weekend was to address some of these issues and hopefully restore this two venerable scopes to working condition. I succeeded in fixing a number of issues (with fantastic help from Charles, 75RR, mrsonchus, MikeA, and others--Thanks!) and will attempt to address the remaining issues soon.

The Orthoplan came without a power supply for the halogen lamp housing, so rather than scour eBay for one, I decided to order an LED replacement from Retrodiode, who makes a series of LED retrofit kits for many vintage microscopes and sells them on eBay. The kit came in two days and fitting it to the lamp housing was a simple matter of removing the bulb and the rear reflector and sliding the LED unit into place. The parts of the retrofit kit are 3D printed and a little crude, but they work just fine. The LED is very bright at its highest settings and, unlike incandescent bubs, maintains the same color temperature as it's dimmed. The biggest issue with the Orthoplan is a frozen field iris. This iris is built into the base of the stand and was frozen in the completely open position. With detailed descriptions in hand from fellow forum members, I plan to tackle this issue as soon as I can find my small gear puller out in the garage. For now, I just use the scope with the iris in its current state. Another issue involved an inability to center the condenser due to old grease impeding the action of two springs built into the condenser body. Cleaning out and replacing the grease fixed this issue.

The Universal also had a litany of issues that needed addressing, such as a stuck mechanical stage, bent parts, and an eyepiece issue. The Universal came with a power supply so I'm using the standard 60W lamp housing, which works fine, but the color temperature changes with the brightness. I'm using the neutral density filters built into the base to vary the light level rather than the control on the power supply.

I took a trip to a local pond and collected some water samples along with some plant material and sand and mud from the bottom. Getting home I prepared a few slides and started scanning them under the microscopes, starting with the Zeiss. The Zeiss came with 6.3x, 10x, 40x, and 100x objectives, so I started with the 6.3x and scanned the slides until I saw something worth examining at a higher magnification. Scanning was a little difficult as one of the axes of mechanical stage is frozen. I ended up offsetting the slide in the holder to scan different parts of it. The samples I took were sparsely populated, but I did see spirogyra, paramecium, vorticella, and lots of diatoms and desmids. The partially frozen stage made following some of the faster critters rather difficult. The Zeiss has a phase condenser, which includes a darkfield setting. I rotated the condenser to the DF setting and wow! Darkfield looks really cool! This is the first time I'd seen DF except in photos, and I'll say that photos don't do it justice at all. DF is like looking at the Milky Way on a very dark night--objects sparkle and shine on a completely black background.

I tried the same slides on the Leitz. The Leitz only has two objectives: a 32x Leitz and a 10x no-name (literally--the painted-on markings are completely worn off). Since the two objectives are not a matched set, they aren't anywhere close to being parfocal, requiring quite a bit of coarse focus manipulation when changing objectives. The Orthoplan has a fully working mechanical stage, so scanning slides and following fast-moving beasties is much easier than on the Zeiss.

So how do the Leitz and the Zeiss compare? That's a very interesting topic and one I'd like to comment on here. Overall, I'd say that the Orthoplan feels like a smoother, more refined machine. The controls feel smoother and the ergonomics, to me, seem nicer. The eyepoint of the eyepieces is better on the Orthoplan and the field of view is visibly wider. Comparing the optics, the winner also seems to be the Leitz. The 32x on the Orthoplan appears to have better resolution and contrast than the Neoflur 40x on the Zeiss. Even the no-name 10x objective on the Leitz looked better than the Neoflur 10x on the Zeiss. The difference wasn't subtle either--both objectives on the Leitz were clearly better than their Zeiss counterparts. I'm not sure why this is--perhaps there's something going on in the optical path on the Zeiss that's affecting the image? Perhaps the infamous tendency of Zeiss optics to have delamination issues? This will require more investigation.

So with a full weekend of using these scopes under my belt, I'm looking forward to getting both fully operational and to start upgrading them with better objectives, condensers, and other accessories.

[billbillt]

Thanks for posting this!... Please keep us updated..

BillT

[Hobbyst46]

This is an interesting post! I love to know how old faulty microscopes are fixed.

A philosophical thought: You are comparing two microscopes while simultaneously upgrading and fixing them so that the difference in quality and performance between the two diminishes in time and may become very slight...

I wonder if anyone had compared a Leitz Orthoplan to a Zeiss Universal years ago, when they were new and at the top of professional labs, and equipped with more or less the same accessories ?

[Charles]

I'm loving this comparison.

Things which may make a difference:

1. There is a lighting difference...one LED and the other 30W tungsten. I wonder if you put the LED one in the back of the Zeiss if you see an improved difference than the tungsten light.

2. Filters in place. The Zeiss has in base filters as well as a filter tray.

3. Are they both set up for proper Kohler illumination?

4. Field of view. Is the eyepieces on the Leitz 30mm vs 23mm on the Zeiss. Larger field of view will make things brighter.

5. Cleanliness of the light train and optics.

6. Objectives. With all things equal, the Neofluars should out perform achro or planachro objectives in resolution and contrast.

[JGardner]

I'm loving this comparison.

Things which may make a difference:

1. There is a lighting difference...one LED and the other 30W tungsten. I wonder if you put the LED one in the back of the Zeiss if you see an improved difference than the tungsten light.

I plan to get Retrodiode's retrofit kit for the Zeiss. In general, I like LED better--closer to white light that doesn't change color temperature as the intensity is varied. One thing I noticed with the LED lighting on the Orthoplan: taking pictures through the eyepieces with an iPhone is a no-go. The photos all come out with zebra strips that I attribute to the PWM used to drive the LEDs. A constant-current power source wouldn't have this problem.

2. Filters in place. The Zeiss has in base filters as well as a filter tray.

I don't think the base filters in the Zeiss had a detrimental effect on the image. Image quality looked the same to me with the filters in place and without them.

3. Are they both set up for proper Kohler illumination?

The Zeiss was. I couldn't set it up properly on the Leitz due to the stuck field iris. I re-established Kohler illumination on the Zeiss when I changed objectives.

4. Field of view. Is the eyepieces on the Leitz 30mm vs 23mm on the Zeiss. Larger field of view will make things brighter.

Definitely noticeable.

5. Cleanliness of the light train and optics.

I haven't yet done a thorough cleaning of all the optics on either scope. I'd say the optics on the Leitz are the dirtier of the two.

6. Objectives. With all things equal, the Neofluars should out perform achro or planachro objectives in resolution and contrast.

That's what I was expecting. The 32x objective on the Orthoplan is labeled L32/0.40 Phaco 1. Other than that, I don't know much about it, such as whether it's an achro, apo, fluorite, etc. It was very clear, however, that the two objectives on the Leitz outperformed the closest equivalents on the Zeiss in both resolution and contrast and this was obviously visible.

[JGardner]

It's interesting what you can find by searching the Internet. In this case, I traced the provenance of my Orthoplan back to a previous owner.

It seems that this scope was owned by the University of Texas, Houston, Medical Center, and was sold at auction two years ago for $180. With a little cleanup and removing some inspection and asset tag stickers, the eBay seller I bought it from got $975, or a tidy return of $795 on his investment.

[Charles]

And to think that when they first came out brand new, fully loaded, it probably cost around $10,000...the price of a small car.

[75RR]

It would seem that 'the suits' never got their hands on the Orthoplan. I suspect it maintained its integrity until production ceased.
However it is noticeable that in many 'Stenciled' Zeiss, as opposed to the Medallion ones, the Field Diaphragm Housing went from steel to plastic and the number of leaves went from 13 down to 6 - one example of 'suits' meddling.

[einman]

It's interesting what you can find by searching the Internet. In this case, I traced the provenance of my Orthoplan back to a previous owner.

It seems that this scope was owned by the University of Texas, Houston, Medical Center, and was sold at auction two years ago for $180. With a little cleanup and removing some inspection and asset tag stickers, the eBay seller I bought it from got $975, or a tidy return of $795 on his investment.

This is rather common. I must say I have been guilty myself, using the profits gained to fund additions to my other scopes. Although I have sold scopes to members at my cost or close to my cost.

[Rorschach]

And to think that when they first came out brand new, fully loaded, it probably cost around $10,000...the price of a small car.

Actually they cost a lot more than that. In the Micscape magazine article, the estimate with inflation accounted for was around 40 000 - 60 000 dollars, depending on which optics were selected and so on. That's not a small car...that's a Tesla

[Rossf]

Hey JGardener -I’ve got a full set of the phaco objectives 160mm-two types-phaco 1,phaco 1a-the phaco 1a’s have a blue background a bit like the Zeiss Neofluar ph2-and like the neofluar objectives the 10,20,32,40 all use the same annulus-the Phaco 1 have a pleasing sand coloured background and are pretty good for most subjects-you can find them cheap if patient-I got three near mint in Australia on eBay for 20 bucks each! I use them on my upright and my inverted-the phaco 1a’s all have long working distance for inverted and don’t perform as well on upright so maybe stick to phaco 1.
Have fun with your scopes.