Microscope features

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lorez2
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Joined: Wed Apr 21, 2021 2:06 am

Microscope features

#1 Post by lorez2 » Mon May 17, 2021 1:17 am

Here is the question .

If you had a limited amount to spend what would be the most important attributes you would want to include when purchasing a microscope
. ?

You may choose new or used microscopes.

The limit is $100 and you can choose five features.

The limit is $250 and you can choose ten features.

The limit is $500 and you can choose 15 features.

lorez
Nikon 80i

BramHuntingNematodes
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Location: Georgia, USA

Re: Microscope features

#2 Post by BramHuntingNematodes » Mon May 17, 2021 2:26 am

Well, what are you wanting to look at?
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

lorez2
Posts: 33
Joined: Wed Apr 21, 2021 2:06 am

Re: Microscope features

#3 Post by lorez2 » Mon May 17, 2021 2:53 am

In your case I guess it would be nematodes, but similar features could apply to much more. I was thinking about a beginner scope.

lorez
Nikon 80i

PeteM
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Re: Microscope features

#4 Post by PeteM » Mon May 17, 2021 3:43 am

Different answers for different types of scopes, of course. Many aspiring microscopists might best begin with a good stereo microscope. An entire world of things to see from, say, 5x to 80x and a better scope makes all that more enjoyable.

Still, pretty sure your question is for compound microscopes. To get your thread started:

Basics:

1) Good mechanical quality of the stand – with a top quality used scope typically offering better for less. One measure of this would be a fine focus with small increments and little backlash for “focus stacking.” Another measure would be that the scope might still be working properly 30 years from now. Still another would be silky smooth but positive adjustments everywhere – the x-y stage, the condenser focus, the coarse and fine focus, the fit of objectives and eyepieces, etc. One either starts with a good quality stand or – should they wish to advance -- eventually gets rid of the initial purchase and begins again.

2) An appropriate (to the price) set of decent quality objectives. Achromats at the lowest price levels. Plan achromats for those interested in taking photos or movies. The availability of plan fluors and plan apochromats as upgrades for someone with a serious interest. Ideally a 4x for scanning (and a condenser to support it), a 10x, the ever-useful but often-omitted 20x, a sharp 40x, and a 60x or 100x oil immersion objective.

3) Sufficient and controllable illumination. Sufficient: enough light to take photos at 100x or do darkfield (oblique, phase contrast, etc.). 20 watts halogen or 3 watts LED might be a reasonable minimum. Older and oherwise excellent scopes can often be converted to 5 to 10 or more watt LED. Controllable – field and condenser irises with a focusable condenser.

4) A wide plan field of view. A head and plan eyepieces with a minimum of an 18mm field number, with 20 to 22mm being more the modern standard, and 25-26mm a delight. This is an issue of objectives (already discussed), the head, and the eyepieces.

5) Decent ergonomics. Some of this comes down to the microscope and some to making sure the table or desk height is right and adding various risers, ergo heads, as needed. Long sessions should leave users delighted, not sore and in pain.

Nice to have (but increasingly costly) multiple methods of viewing and adding contrast:

6) Simple polarization. Cheap if there’s room under the head for a polarizer.

7) Darkfield. Cheap up to about 200-400x if the condenser can support annuli. Higher power darkfield will require a darkfield condenser and perhaps an objective with an iris.

8) Epi illumination and no cover objectives. Useful add-on – especially for examining the built world. Long working distance objectives for more control of external lighting.

9) Phase contrast. Cheapest to buy at the outset if one knows they’ll surely want it. That or just buy a for-phase-contrast mainly second scope.

10) Fluorescence. Perhaps for those hoping to track proteins and the like.

11) DIC. Not cheap, but a visual delight.

12) Interchangeable nosepieces for anyone who anticipates multiple imaging methods. Maybe a $100 add to the cost of a good quality used stand.

Photo and movie documentation

13) A cell-phone holder and cable release for starters ($20).

14) A trinocular head and well-documented means of getting top quality images on to a dgital sensor. Some cheaper scopes have only cheap options. There are also some hoops to jump through on some older pro-quality scopes. Nikon and Olympus are best documented and easily adapted from C-mount through full frame options, with perhaps a slight nod to Nikon finite systems over Olympus finite systems for their chrome-free objectives. Infinity scopes can often go direct to sensor, with a neutral projection lens of some magnification to get an appropriate frame size.

15) Surely more to come . . .

BramHuntingNematodes
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Re: Microscope features

#5 Post by BramHuntingNematodes » Mon May 17, 2021 5:26 am

I do make extensive use of phase contrast. I always buy used not because I think Zeiss has always made better optics but because someone took apart their GFL in the driveway and let me buy it from them for $25. So, that way of acquiring equipment you generally don't pick out features a la carte but what you can do is look at the bottleneck in your optical train and look to improving that. I remember early on I spent a long time with this here Dynoptic trying to get a light that worked well with it. I built a few boxes, and took them back apart a few times before I finally got one I was happy with. I looked around for an aplanatic condenser to squeeze a little better performance out of it. I had a mechanical stage with it, but the dials only moved forward and backward. Left and right I had to do by hand. I lived with that for a good while before I saw a stand in good fettle for a few bucks.

I don't have any planapos. Have some regular apos and I like them just fine. The Balplan planachromats I found, similar in performance to the Reichert plan achros, work well enough for just about everything though, with good depth of field. I got a Microstar IV the other day for about $85 all outfitted even had a bulb. So maybe the list is off there. In a case like that, the first $100 buys 15 features. The next $3-400 buys maybe 2 or 3 more expensive features. Maybe a couple of fluotars, or maybe some phase equipment.
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

apochronaut
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Re: Microscope features

#6 Post by apochronaut » Mon May 17, 2021 11:36 am

Good question.

Your question is quite explicit by putting caps on the amount available to spend on each microscope. A budget is always a good idea, since most people actually have to pay for their equipment. One can ramble on about this or that feature ad nauseum but without the money to spend on them, they are all moot points. Donations might be nice.
I don't have much experience in buying new microscopes but I can easily determine from the literature how their features stack up. I have handled quite a few, though, and had the opportunity to examine their strengths and shortcomings in adapting or repairing them. I have had a lot of used microscopes in my hands.

$100.00. You can't get much for 100.00 in a microscope, especially if you are needing for one or more reasons to buy new but 100.00 can get you a lot in a used microscope.
NEW. Five features. Fine focus, 3 objectives, a condenser, variable intensity, wider than normal field. That's about all one could expect, really.
USED. The above 5 features are implicit minimums with these additional five features. Binocular w.f., 4 objectives to include a higher N.A. oil immersion one, focusable condenser with 1.25 N.A., mechanical stage, a tray or slot for filter installation. Basically a conventional small lab scope. It is assumed that the fine focus supplied on any used lab scope has precision to 2 microns.

$250.00. For me, this is the starting point in being able to purchase a microscope that can start to "perform" beyond expectations.
NEW. Binocular with a minimum 18mm field# , mechanical stage, focusing condenser with 1.25 N.A. , 4 objectives to include an oil immersion type, filter tray. Pretty much the same as the used one above with again, an assumption that the fine focus has a standard precision.
USED. All of the above plus. Plan achromat objectives(4), trinocular head, field lens and diaphragm, DF condenser, 20mm f.o.v. Many better stands have a 1 micron fine focus, so that might be looked for.

$500.00. For 500.00 a microscope that has "extra" professional features should easily be possible but in new versions, there isn't enough separation between standard small lab scopes and what would be considered the more elite scopes. The big changes are mostly just size and cosmetics with plan optics being the one important heralded feature. No achromat condensers, no 1.3 N.A. objectives, no 1 micron fine focus. Maybe a 3 watt over a 1 watt led.
NEW. Plan Achromat optics, a 20mm or greater f.o.v., DF condenser, trinocular head, field lens and diaphragm.
USED. All of the features in the used 250.00 scope only replaced or upgraded by the following.At least some of the totàl of 5 or 6 objectives as planfluor or planapo , higher N.A. achromat/aplanat condenser, 5 or 6 place nosepiece,100 watt, 100X iris diaphragm equipped or funnel stop equipped objective lens.


In the case of the second hand microscope options listed above, the features mentioned are not a wish list. They are real lists that I have purchased, and not just once. Multiple purchases and fairly recently too, so they are not anomalies.

dtsh
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Re: Microscope features

#7 Post by dtsh » Mon May 17, 2021 1:15 pm

I've always bought USED so my perspective might be different. While good optical components allow for better images, the low end (discounting "toys") are still usually quite good and a lot of times a beginner would be entirely satisfied with them and most of the instruments from yesteryear will serve quite well. I think it's important to mention that to take stunning images requires a significant invesment in both equipment and skill, but that one can take good images with any decent microscope with care. There are some features that I feel a microscope must have, such as a mechanical stage, which I feel is an absolute necessity, and other features which are nice to have, but not an absolute such as a height adjustable condenser or a field iris.

Typically the price I am willing to pay fluctuates with features, but there are some really good deals to be made for the patient. What I've seen of the used market suggests that there's a lot of junk and scratch and dent instruments, often listed by unscrupulous people as being in much better condition than they are so the buyer needs to be aware of whatever protections are in place and to enforce those protections when they encounter these people. That said, I think most are honest enough, but usually not terribly familiar with the equipment they are selling.

My most recent acquisition was an AO One-Fifty with Phase contrast for $63.30 delivered. It's a basic model microscope, but with a mechanical stage. I had to clean it up and align some parts, but it was otherwise in great condition and I am currently exploring it's limitations. It certainly exceeds what I expected of it.

For anyone looking at used stuff, I highly encourage them to acquire some appropriate grease, cleaning supplies, and a phase telescope (not absolutely required, but it certainly helps)

lorez2
Posts: 33
Joined: Wed Apr 21, 2021 2:06 am

Re: Microscope features

#8 Post by lorez2 » Mon May 17, 2021 6:23 pm

WOW !

When I posed the question I was expecting some brief lists such as: eyepiece fine focus, mirror, etc., but you have all gone way beyond my meager expectations. What a wealth of information.

Hopefully, it will be a source for those just beginning who have limited experience and are looking for some guidance.

lorez
Nikon 80i

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