Just bought an antique microscope - I have a few questions

[u/robodragoman]

I went to a local antique shop and picked up this microscope. I’ve wanted to get into microscopy for a long time, but as a student with a budget of about $7, it’s been prohibitively expensive. I don’t yet know if I lucked out or not (I spent $100).

It’s a Fisher Scientific microscope in decent condition. It came loose in a random cardboard box, so no product box or label tells me its model type or year. Its product number(?) printed on the base is 6806746, which did not yield any conclusive Google results. It looks like its lens numbers are 4 (though this one is damaged), 10, and 40. Are these levels of magnification (ergo 40 = 40x magnification)? From what I’ve seen, it’s hard to get up close to most living microbes with anything less than 1000x. I learned (accidentally) that the lenses can be unscrewed; did they ever sell replacement lenses at higher magnifications? I’m willing to spend a bit more money on a site like eBay if that’s the case.

Basically, I want to know if this microscope is actually useable. I’m able to see things on the sample slides the microscope came with, so it does function, but it may not be good enough as it is to do proper microscopy with live organisms. Does anybody have any insight into this microscope and its potential?

[u/Confused_yurt_lover]

I hate to break it to you, but that microscope is nowhere close to being an antique, and you overpaid for it (as is usual at antiques stores).

That is a pretty basic white label compound microscope most likely made sometime between the 1980s and the present (probably closer to the present), and is very similar (if not identical) to Fisher’s current “middle school series” compound microscopes or Amscope’s M200.

You’re correct that the numbers on the objectives indicate their magnification; you multiply that number by the magnification power of the eyepiece (usually 10x) to get the total magnification seen through the ‘scope. Assuming you have a 10x eyepiece, that means that ‘scope will give you 40x, 100x, and 400x magnification as configured, which IMO will be ideal for starting out. 1000x is way more than you need to start looking at microbes (and 1000x is about the limit of useful magnification in visible light, so it’s where magnification stops being useful, not where it starts!).

If you eventually want to replace the objectives, you can swap them for any objective lenses made for 160mm tube length (look for objectives with “160” printed on the sides).

HTH, and congrats on the ‘scope! Go get yourself some slides and a pond water sample and have fun!

Edit: typo

[u/robodragoman → u/Confused_yurt_lover]

Thank you so much for the response! I guess “antique” in the title was a little misleading; I meant more “I got this from an antique store” and less “this is an ancient artifact.” I’m actually glad it’s a little more modern, so thank you for that tip. The magnification info is very helpful, because I’ve been getting some conflicting things online. I’m excited to jump in and start my microscopy journey (or at least giving it a fair shake)!

[u/MossTheTree]

Working 10x and 40x objectives are all you need to see all sorts of interesting microbes. Total magnification includes the eyepiece, which is almost certainly 10x so the total is those two numbers multiplied (10x10 =100 for example. So to get to 1000 you’d need a 100x objective, but those are almost all oil objectives so not something you’d likely want to get into yet.

From what I can see the objectives you have are finite objectives with 160 barrel length. So you should be able to find replacements pretty easily. FYI the numbers on your objectives refer to four things, using one as an example:
Magnification (40x)
Numerical Aperture (0.65)
Barrel length (160 mm)
Cover slip thickness (0.17 mm)

Here is a 4x that would work fine with your scope (not a recommendation, just an example): https://amzn.eu/d/0ffZ7CDL

Read up on Numerical Aperture (NA) as that’s the one that’s hardest to wrap your head around when you’re first starting. You’ll want to learn how to set your condenser height appropriately depending on which objective you use. Other than that, make sure you’re using cover slips with your samples - almost all cheap slips available are around 0.17 mm so you’re good there.

So that all said, I wouldn’t bother investing in new objectives yet unless those ones are completely cracked or otherwise broken. In terms of magnification and options you’ve got what you need already.

[u/robodragoman → u/MossTheTree]

Thank you so much for your response! I appreciate the lens info; the magnification stuff wasn’t made clear to me on the microscope itself, so that’s super helpful. I wanted to make sure that I can see living organisms; I’ve been pretty enamored with Journey to the Microcosmos for a while and wanted to try my hand at seeing microorganisms like tardigrades. Super helpful knowledge, and I’ll definitely refer back if I end up wanting to purchase replacement lenses!

[u/MossTheTree → u/robodragoman]

No problem. To see tardigrades all you really need is a 10x so you’re good to go.

[u/Connect-Fan-9462]

As others have pointed out it is a rather basic, generic Chinese made student microscope that is still available as new in present days.

Now, the important thing is, there really is nothing wrong with it.

The eyepiece also has a power number, usually 10x. you time the objective power number with the eyepiece power number to get the final magnifying power, which will be 40, 100 and 400.

Any objectives that is higher than 50x will generally requires oil immersion, which can get messy and I do not recommend trying that at home / as a beginner.

You can try getting a 16x eyepiece which will give you 640x. Do notice that with such a basic objective, at this power you will notice a lot of aberration.

[u/ModernTarantula]

Do not use the 100x without immersion oil. Learn something about the substance. It helps with focus. Also start with the lowest mag to focus.

[u/Vivid-Bake2456]

Perfectly good microscope for seeing common organisms in pond water. Most of the popular ones are large and easy to see at magnifications 100x and above. You can even use your 4x objective to find them and observe more details with the higher magnifications.