Antique microscopes usability

[imkap]

Just how usable are antique microscopes? I found this one, looks good and it is fairly cheap and not too big. Might be good for our cottage...

[Alexander]

IF the optics are clean and the mechanical parts work, it would be usable. Still better than most of the Chinese crap sold new.

[imkap]

I have some extra eyepieces and objectives I could use. Is there anything in the tube in between?

[Alexander]

Is there anything in the tube in between?

Most probably not.

[imkap]

Most probably not.

I think so too... I think I'll get this one

Thanks

[imkap]

Not sure on the pictures if the condenser is complete, maybe missing top lens. I'll call the seller to make a picture or a video call.

[apochronaut]

That one has a very useable stage. It looks to be rotary. The large brass knob facing the camera may be the lock for the stage but if there is one on the other side, it is one of a pair to control a stage with an orbital xy control. The entire stage can be moved around the axis of the condenser, rather than just the slide. All you need is a couple of stage clips and you have a beautiful rotary xy stage. The stage is worth more than an entire Chinese small lab microscope.
If the condenser top lens turns out to be missing , it is probably because the previous user removed it to lower the N.A. and broaden the field for lower magnification objectives. It will work well still, up to about .70 , so good for objectives below 4mm or about 40X.

[imkap]

It would be very interesting to examine it and try to refurbish it. There is a writing on behind, says: university department of experimental pathology maybe some disinfection should be in order...

There is a similar one too not too expensive available too both sell for about 80€, this one looks newer, has a condenser and 3 objectives, maybe I buy both and see which one is better, easier to use and try to assemble everything and sell one... Although I like the brass one more, for the looks and the stage.

[apochronaut]

There is a writing on behind, says: university department of experimental pathology maybe some disinfection should be in order...

The previous user collapsed before he could screw the condenser top back on.

[imkap]

The previous user collapsed before he could screw the condenser top back on.

[imkap]

These scopes should be 160mm both?

[apochronaut]

Many earlier monocular microscopes had a graduated drawtube that could be set to match the tubelength of the objective being used. Lots of pre w.w. 1 microscopists would choose objectives from various manufacturers to fit their needs and screw in the objectives one by one, replacing eyepieces too. Since not all mfg. had fully committed to R.M.S. uniformity, the drawtube was a needed accessory.
The first microscope you posted, has a drawtube, so it is in fact universal, adjusting likely from 150mm to 200 or even 250mm. The one objective in it appears to be a Leitz, so it is 37mm parfocal and a 170mm tube

The second microscope is a Reichert, also 37mm parfocal but a fixed 160mm tube.

[imkap]

Thanks for the info. I think I'll buy the brass one tomorrow

[Greg Howald]

The brass scope has the plus as it can be used for polarized petrographics. The focus is achieved by adjusting the height of the objective rather than the stage. Stage height is fixed. Rather than adjusting x and y on the stage, the controls under the stage will rotate the stage. By polarizing at extinction to start, degrees of polarization will be easily established. It is a good and interesting scope.
Greg

[BramHuntingNematodes]

B&l monocular scopes had a graduated drawtube as late as 1938, but maybe even later. 1938 is just the age of mine with one

[apochronaut]

It continued to be an option . I think I have seen an AO model 35 with one , so it would be late 40's.

[Chas]

Of course you could always get both of them
The advantage of the second one is that it (looks to) have a short main tube, which means that if you want to take photographs with a dslr you can pull out the draw tube and attach the dslr without effecting the tube length a great deal.

It also has the remains of a flexible type of x-y stage system ..but it would need some wedges making to fit into the grooves to hold the sideways-gripping slide arms, which are missing too.
Of course those could be too fiddly to make.... which might in the end might involve buying a third one ...just for parts...which could lead to.....

[imkap]

The brass scope has the plus as it can be used for polarized petrographics.

I suppose I'd need some more accessories for that, but nice to hear that. I've just called the seller and he'll send it tomorrow. I'll keep you posted

Of course you could always get both of them

I've ordered the first one, the other one is on for some time now, so don't think it will go anywhere soon. Local microscope market isn't that fast moving.

I'll see what I'll make out of the first one... Never used a rotary stage, although not sure where to get the stage clips, maybe make them out of something?

[imkap]

.... which might in the end might involve buying a third one ...just for parts...which could lead to.....

The seller actually told me he has some channel for getting more of them... We'll see...

[apochronaut]

You can buy stage clips on ebay but sometimes they are asking a ridiculous price. They are not universal. The pin diameter can vary quite a bit. Good ones are actually very thin spring steel. Cheap chromed mild steel ones were widely used on hobby microscopes and can be bent.
You will have to measure the pin size, then determine the ideal length from the pin to the tip. You want the clip to just reach over to the far side of the slide when the sample is centered . I'm pretty sure that is an orbital xy stage, so the clips will just be used to hold the slide. You won't be moving the slide around with your fingers under the clips, as is the case with a plain stage with clips.

The come in three basic designs.
1) The clip originates from an elevated location on the pin and is a downward curved arc with an upturned tip. The downward curved arc provides spring pressure on the slide, clamping it firmly to the stage primarily near to the tip.
2) The clip originates a little lower on the pin and is generally flat with an upturned tip. The clip maintains a flat profile across the slide clamping it with spring pressure.
3) This is a more modern design that incorporates a coil spring coaxial on the pin to exert spring pressure on a stepped clip that has a flat profile across the slide. The spring lifts the clip slightly to place the slide under it and it is then compressed to clamp the slide a little.

Older ones are either chrome on brass or chrome on steel. Modern ones are more often ss.

[AntoniScott]

I would generally say that antique microscopes are not very usable for a variety of reasons. Decades of prior use and unknown storage conditions could have a negative effect on the inner, outer and internal glass surfaces. A condition called "delamination" is something that can happen. More likely, the surfaces inside the objective glass elements may collect a residue from air exchanges, heat and cold condensation of atmospheric water, etc. Same for th eyepieces but they are easier to disassemble to clean indiviual elements if necessary.
I have a beautiful antique Seibert Wetzlar microscope (actual year is unknown but probably between 1890 and 1905) that has four objectives. I believe this scope predates Leitz of the same era. It is a beautiful example of precision workmanship. The four objectives are all working but with varying optical quality that I attribute to age not manufacture. Interestingly the objective that approximates the 40x magnification has spectacular image quality. I'm afraid to disassemble anything for fear of damaging something. My vintage scope is my prize microscope.

[dtsh]

I have and use an older AO Series 35 scope from 1951; it's not quite as old as some of the other fine examples shown here, but I have found it to be a nice instrument in general. The objectives do not deliver the performance of today's best objectives, but they do perform acceptably well for me considering it's over 70 years old. Most of the objectives (2/3) are uncoated, so deliver a little less contrast and they are not plan, but for what it cost, it performs amazingly well. Mine came with a 17w tunsten lamp, but I wish it had a mirror.

Here is a link to a quick overview of it to have an idea of what a similar instrument in quality and age might perform if in decent condition. viewtopic.php?f=24&t=14896

Due to the combination of it's size, performance, and cost it is my preferred microscope for travelling and sharing with friends. It has limitations of course, but where cutting edge performance, flat field, and wide FOV aren't necessary they can work fine. As with any used instrument, caveat emptor; know what you're getting, have assurances, or be willing to gamble and lose.

[apochronaut]

Delamination is a manufacturer specific and era specific thing. Some makers had known problems and others less so and the problems went in bunches. This was most likely the result of poor cement , poor production technique or even possibly a sloppy employee. Doublets and triplets are done in batches, so often a group of objectives with consecutive serial #'s can all have delamination in the same optical element. The good thing is, these can sometimes be easily repaired or good replacement examples found on ebay for very little. The microscope the poster is buying has only one objective, a Leitz, and they have a pretty good track record for remaining stable over the years.

An average type achromat microscope with a standard type of stage and substage, unless it is really cheap, might not be worth the gamble but some older stands had really fantastic features, that in a modern microscope would cost many thousands if dollars and when it comes to basic Chinese stands, wouldn't be available at any cost.
Just to my right where I am sitting is a Spencer #7 CHB that cost under 100.00, with a case. It has 3 apochromats that work perfectly with 10X and 15X eyepieces, so 6 magnifications between 100X and 1275X. The prize though is a 1.4 N.A. achromat/aplanat condenser with a second offset diaphragm on a fine rack and pinion for oblique and a cardioid DF condenser. I added a 50.00 Spencer 95X achromat DF objective., so it can do 950X DF. Everything works flawlessly. The stand is almost entirely brass and exceedingly stable despite having a small footprint. It's only real defect is it's relatively narrow f.o.v., at around 13mm. Why this sounds puny, it isn't so noticeable in use. One adapts quickly and the field seems quite wide.
To buy a microscope with the features it has new, today, would cost in the many thousands. Mind you it would give better imaging but old microscopes should be looked into for what they offer, not what they might not. Some are outstanding bargains, easily better than a cheap Chinese stand.

[imkap]

I intend to use newer optics with this one, It will be interesting to use and renew the old mechanics. In the worst case can sell it on for the similar price probably if I don't like it...

I enjoyed fiddling with my GFL, so this was kind of a logical sequel

[imkap]

Here is a link to a quick overview of it to have an idea of what a similar instrument in quality and age might perform if in decent condition. viewtopic.php?f=24&t=14896

Your results look quite nice, I'd be very happy with that.

[imkap]

I think your antique wetzlar looks great, it is a bit similar in construction to the one I ordered...

The pin diameter can vary quite a bit. Good ones are actually very thin spring steel.

Not sure if I'd like to pay a lot of money for those... Probably some DIY will be in order. I hope the holes will have a standard M thread.

[apochronaut]

The only ones I have seen that were threaded into the stage were on a stereo microscope and on some student microscopes where they didn't want them to end up as jewellry.
Usually they just press fit into a hole in the stage. Nothing wrong with drilling the hole bigger, if need be.
If you end up diy'ing the stage, I would dispense with stage clips altogether . Their role in this case is just to hold a slide fast, not also allow it to be manually moved . You can probably find a derelict slide carrier from a standard mechanical stage and fasten it as a slide holder. The mechanical slick movement part of that stage is already intact as an understage mechanism.

[BramHuntingNematodes]

Is 1942 antique? I did put on newer eyepieces (the wf-22), but everything else on it is about contemporaneous. It works great, real sharp. It's got the gross and fine focus knobs both up high but I'm used to it.

Thing about a hundred years ago is the microscopes were mature technology by then and in regular use by professionals. They were and are highly useable instruments.

[Chas]

AntonniScott... that is a fabulous microscope ...I quite understand that you would not want to attack the objectives yourself.
But just as a cataract operation can bring an elderly person a new lease of life .. perhaps there is someone on the forum who has the knowledge+patience+skill and correct tools, to do this for you (??)
I am sure that there is always a risk, but cleaning can sometimes transform the existence of the microscope
But I guess that you must have already considered this.

[apochronaut]

Seibert were one of the companies that has a history of delamination, similar to Zeiss. They stopped producing microscopes altogether and concentrated on optics eventually. Their later objective production seems pretty good. They made optics under contract for a number of small companies and produced contract optics for Leitz as well.
Fortunately, in retrofitting an older microscope like that one, if there are one or more dud objectives, Leitz objectives can fill in almost seamlessly and are in much greater supply.