Beginner's Scope buying tips + polarization questions

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BrianBurnes
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Beginner's Scope buying tips + polarization questions

#1 Post by BrianBurnes » Sat Feb 08, 2020 10:27 pm

Hi all!

I'm looking to get back into hobbyist microscopy after a 10 year hiatus or so, and I'm looking for a few pointers regarding beginner's compound microscopes that would be right for my case. I'm mostly fascinated by protists like ciliates and diatoms and would love to see some up close; I'm not sure which kind of magnification that requires. Trinocular is a definite plus, but not necessarily required (I do not have a DSLR but a decent phone camera). I do computational optics during the day, and being able to tinker a bit with the physical optics would be fun (I saw some condensers allow you to insert filters of all kinds, but I'm not sure of the cost).

Having done a little bit of research, it seems that phase contrast micoscopy is definitely out of my budget, but I would love to do darkfield and polarization. So far I have not seen an affordable microscope that does both; in my basic understanding, darkfield microscopy involves placing (and centering!) a masking disk in the light path of the condenser, and polarization means placing a polarizer before- and after the sample. Would it be feasible to McGyver either of these methods into a microscope that does not support it out of the box, or is that not recommended?

My budget is $300-$400 (US based). Are there any decent beginner microscopes that would fit the bill? I'm fine with buying a used microscope if that's a good idea, but I'm unsure which brands/features to look for in a listing.

Thanks in advance!

PeteM
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Re: Beginner's Scope buying tips + polarization questions

#2 Post by PeteM » Sat Feb 08, 2020 11:06 pm

Brian - sounds like a quality used "system" scope would be perfect for you. These will easily allow all sorts of optical add-ons and have excellent optical and mechanical quality in your price range.

It's pretty easy to add a darkfied stop under a condenser for darkfield up to 20x (200x with 10x eyepiece magnification) and perhaps as high as 40x (400x). Beyond that you'd be looking for a used darkfield condenser.

Simple polarization is also easy - you just want a scope with room to fit a polarizing filter between the stand and head. Then another filter on the field (bottom of the scope) lens. Cheap camera polarizers, once flipped the right way, will do and come in a variety of sizes. You should be in business for maybe $25 IF there's room under the head to insert one of the two. You can get a bit better extinction with OEM polarizers, but those might cost $200 or so, even used.

If you'd like, once you have enough posts to send a message, let me know an email address and I can send you a PDF of the guide to over 50 brands and maybe 200 models of new and used microscopes. You can also search past posts for suggestions - yours is a common question.

BrianBurnes
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Re: Beginner's Scope buying tips + polarization questions

#3 Post by BrianBurnes » Sun Feb 09, 2020 5:05 am

Thank you for the reply Pete!

Interesting! I have not heard of system microscopes before. What does that entail?

I have been digging through older posts in the beginner's corner and I'm starting to get a picture. I've seen AmScope recommended. As a first approximation, what about this?
https://www.ebay.com/itm/124075434719
The plan infinity optics are a nice-to-have for toying with things in the optical path. I'm unsure what kind of condenser is under the stage, but the T690C claims to have Kohler illumination, so perhaps it is that? There is some concern over the missing camera adapter and what objectives are included (I can only spot 3, but the 4th may be hidden), but would this be a reasonable listing?

A PDF guide would be very helpful - I don't know if you are able to send me a private message with a link to the guide, but otherwise I could certainly post my email address here and edit it out after you've sent it.

PeteM
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Re: Beginner's Scope buying tips + polarization questions

#4 Post by PeteM » Sun Feb 09, 2020 5:55 am

Brian - a PM sent.

Given your background in computational optics and desire to tinker a bit, I'd consider a used 70-80's era professional microscope such as an Olympus BH-2, Nikon Labophot, Leitz Laborlux, Zeiss Standard, or Reichert Microstar. These "system" microscopes are a bit like a professional camera - there are all sorts of additional lenses and attachments (available from sources like Ebay) to do a very wide variety of viewing tasks. The guide will have more info -- and lots more models to consider.

The AmScope you linked to is a decent Chinese scope, complete with a trinocular head, and reasonably priced if you were to get it around $300 plus reasonable shipping. If in good shape, a good start. I don't know if that model has room under the head to put a polarizer, but it seems likely.

Optically, it might be about as good as one of the models listed above with regular plan achro objectives. Mechanically it will be a step behind. Perhaps of greater interest to you, there won't be as many options or affordably priced if you want better objectives, a darkfield condenser, eventual phase contrast, and so on in the future.

MichaelG.
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Re: Beginner's Scope buying tips + polarization questions

#5 Post by MichaelG. » Sun Feb 09, 2020 9:04 am

BrianBurnes wrote:
Sat Feb 08, 2020 10:27 pm
Hi all!

I'm looking to get back into hobbyist microscopy after a 10 year hiatus or so […]

Having done a little bit of research, it seems that phase contrast micoscopy is definitely out of my budget,
Welcome, Brian

Before you give-up on the idea of Phase Contrast ... Have a look at the Swift Quodmaster system
Those Japanese Swifts were quite nicely built, and the phase system is cleverly done.

https://www.swift-microscopeworld.com/I ... Manual.pdf

MichaelG.
Too many 'projects'

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75RR
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Re: Beginner's Scope buying tips + polarization questions

#6 Post by 75RR » Mon Feb 10, 2020 6:54 am

There are some good deals to be found if you are US based, as postage is very reasonable and there are no border taxes.

Here is a reasonably priced Zeiss Standard 18 (interchangeable nosepiece) with a Phase condenser and what looks to be two Phase Achromat objectives.

Achromat Phase objectives are very economical, so you can pick up a couple more quite cheaply.

Zeiss has Achromat, Plan, Neofluar and Planapo Phase objectives - so plenty to choose at everyone's budget.

Microscope looks complete, just missing a power supply - see second link.

As you have previous microscope experience you should not have any problems buying used.

https://www.ebay.com/itm/Carl-Zeiss-Bin ... ondition=4

https://www.ebay.com/itm/CARL-ZEISS-MOD ... SwD39aZ8Y9

Note that the connector tube clipped on to the lamphouse is meant to be fixed to the microscope. Small screw is all it takes.
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)

BrianBurnes
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Re: Beginner's Scope buying tips + polarization questions

#7 Post by BrianBurnes » Tue Feb 11, 2020 2:11 am

Thank you for the suggestions all! This has been very helpful. I have a much better idea of what to look for now, and I'm keeping a watchful eye on ebay until something interesting pops up.

BrianBurnes
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Re: Beginner's Scope buying tips + polarization questions

#8 Post by BrianBurnes » Sat Feb 22, 2020 5:13 pm

Hi all,

I've acquired a used trinocular Microstar IV with 4 neoplan objectives for $140, which seemed like a decent deal:

Image

The stage is unfortunately a bit busted (XY and condenser adjustments are almost seized up, and the specimen holder is missing), but that seems cheap to replace. Other than that the microscope appears optically and mechanically sound.

Some beginner's follow-up questions:
- What kind of adapter do I need to attach a camera to the trinocular portion of the head? I've been looking through Reichert/AO catalogs but have been unable to find anything that attaches to the dovetail (seems to be 40mm). Worst case an adapter can be 3D printed, but I'm unsure if I need active optics to get a useful image out. Does anyone know more?
- How big of a quality improvement can I expect going from neoplan to plan objectives? It looks like matching 10x and 40x plan objectives can be obtained easily for perhaps $80 or so total, but I'm curious if it is worth it.
- How much interopability is there between this model and the rest of the Reichert/AO/Leica catalog? For example, can I use other infinity reichert/AO objectives on the 410? I've read that they have different parfocal distances, but I'm not sure what that entails. What about condensers? The microstar iv darkfield condenser seems hard to find. What about heads? This trinocular head unfortunately only has an "either-or" lever, where I can't look through the eye pieces and simultaneously get an image out the top. It would be great if I could replace this with a head that has a beamsplitter. I've read that the dovetails have similar radii between models, but the head also seems to have active optics at the bottom that may not be compatible with other models.

For now I'm quite happy with this buy, it seems like a useful model for tinkering - I will probably attempt to convert it to LED lighting and add polarization - but sadly it's difficult to find matching attachments that go in the optical path between the head and the objective (I was hoping to hack in epi-illumination at some point). In the meantime I might look for cheap broken microscopes of other models to slowly build up a frankenscope on the side.

Hobbyst46
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Re: Beginner's Scope buying tips + polarization questions

#9 Post by Hobbyst46 » Sat Feb 22, 2020 5:28 pm

BrianBurnes wrote:
Sat Feb 22, 2020 5:13 pm
...sadly it's difficult to find matching attachments that go in the optical path between the head and the objective (I was hoping to hack in epi-illumination at some point).
If the purpose of epi-illumination is just top light for photography at low magnifications (~2X-5X objectives), relatively cheap solutions are small focused-beam desk lamps, fiber optic lamps and DIY focused LED beams. "True" epi-illumination is critical for fluorescence.

Congratulations on the nice microscope !
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

PeteM
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Re: Beginner's Scope buying tips + polarization questions

#10 Post by PeteM » Sat Feb 22, 2020 5:41 pm

Brian - the MicroStar is a very good scope and you did great to get one with a trinocular head at such modest cost.

I don't think you'll see much difference from Neoplan to Plan objectives, assuming all the ones you have are in good shape. You can swap any DIN standard infinity Reichert (or Cambridge, Leica of the era) objectives of 45mm parfocal though. And consider the plan objectives once you get a camera hooked up and find you want a bit more field flatness. the Neoplans are pretty good.

Can't really advise on a solution to hook up a camera. I ended up machining an adapter. You don't necessarily need a projection lens with an infinity scope, so it's a matter of getting a right-sized camera sensor the proper distance above the trinocular port. You can guesstimate this by simply holding the sensor above and measuring the distance and then finding/making an adapter with a bit of vertical adjustment to get it just right and parfocal.

It's not clear if there is a slide holder on yours - you'll want that if not. Also not clear if there is a 20x objective - that's a wonderful magnification to have and the AO / Reichert 20x are very good. They're a bit hard to find. A generic Olympus clone 20x infinity isn't too bad on that scope.

You might be on the lookout for one of the square shaped polarization turrets that fit on top of the stand (with your trinocular head on top of that). These are often very affordable.

As for the Epi option, you can probably buy a complete epi scope for about the same price and hassle as trying to hack yours. Your current objectives won't be the best for epi and you might also want a darkfield option.

BrianBurnes
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Re: Beginner's Scope buying tips + polarization questions

#11 Post by BrianBurnes » Sat Feb 22, 2020 6:16 pm

PeteM wrote:Brian - the MicroStar is a very good scope and you did great to get one with a trinocular head at such modest cost.
Not least thanks to your guide!
PeteM wrote:You can swap any DIN standard infinity Reichert (or Cambridge, Leica of the era) objectives of 45mm parfocal though.
That is very good to know. Would the 34mm parfocal objectives also be usable (assuming I do not mix 45mm and 34mm objectives), or do the optics not work out?
PeteM wrote:You don't necessarily need a projection lens with an infinity scope, so it's a matter of getting a right-sized camera sensor the proper distance above the trinocular port. You can guesstimate this by simply holding the sensor above and measuring the distance and then finding/making an adapter with a bit of vertical adjustment to get it just right and parfocal.
That seems doable. I do not currently have a camera with exposed sensor (and my cell phone camera certainly produced no usable image out of the trinocular port), so I will have to wait until I pick up a DSLR.
PeteM wrote:It's not clear if there is a slide holder on yours - you'll want that if not. Also not clear if there is a 20x objective - that's a wonderful magnification to have and the AO / Reichert 20x are very good. They're a bit hard to find. A generic Olympus clone 20x infinity isn't too bad on that scope.
Slide holder is missing, but I'm replacing the stage in any case - should not be too hard to find. The scope only came with 4x, 10x, 40x and 100x sadly, but I'll be on the lookout for additional objectives. That's interesting! I got the impression that infinity objectives were not compatible between brands. What is the situation when mixing objectives? Does it still produce a usable image?
Hobbyst46 wrote:If the purpose of epi-illumination is just top light for photography at low magnifications (~2X-5X objectives), relatively cheap solutions are small focused-beam desk lamps, fiber optic lamps and DIY focused LED beams. "True" epi-illumination is critical for fluorescence.
PeteM wrote:As for the Epi option, you can probably buy a complete epi scope for about the same price and hassle as trying to hack yours. Your current objectives won't be the best for epi and you might also want a darkfield option.
All excellent points. There is some fun in making things, but optics tend to be quite finicky to work with. I'll be on the lookout for a proper epi-scope - I have a few etched silicon wafers that I'd like to look at, and it would be a useful option to have around. What is the darkfield situation on the Microstar IV? Is that easy to add, or should I add that to the list of things to look out for in a new scope?

PeteM
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Re: Beginner's Scope buying tips + polarization questions

#12 Post by PeteM » Sun Feb 23, 2020 3:57 am

BrianBurnes wrote:
Sat Feb 22, 2020 6:16 pm
. . . Would the 34mm parfocal objectives also be usable (assuming I do not mix 45mm and 34mm objectives), or do the optics not work out? . . .
The 34mm infinity and 45mm infinity objectives are very similar. However, the color and field corrections changed a bit from generation to generation (e.g from Series 10 era, to Series 100 era, to Series 400 era - what you have). Given that you already have objectives from the 400 series era, I'd stick with that. The other options:

- Just use your stand and convert the all objectives and head to a matching series. Not much sense in that.

- Use a parfocal adapter of 11mm and make do with a short barrel AO objective with the rest of your AO/Reichert/Leica 45mm infinity objectives. Corrections will be a bit off, but you might find these pretty decent on an interim basis. This might make sense if you stumble across a cheap 20x, maybe a fluor or apo in a short barrel objective. The extra 11mm won't be so much a problem as the corrections in the tube lens - so you could swap heads if you were doing critical photos or something like that.

blekenbleu
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Re: Beginner's Scope buying tips + polarization questions

#13 Post by blekenbleu » Tue Feb 25, 2020 6:52 pm

BrianBurnes wrote:
Sat Feb 22, 2020 5:13 pm
- What kind of adapter do I need to attach a camera to the trinocular portion of the head? I've been looking through Reichert/AO catalogs but have been unable to find anything that attaches to the dovetail (seems to be 40mm). Worst case an adapter can be 3D printed, but I'm unsure if I need active optics to get a useful image out. Does anyone know more?
40mm seems unusual; this vendor lists adapters for 35,38,42, and 44mm dovetails: https://www.lmscope.com/en/LM_Mikroskop ... pe_en.html
Consider hacking a T2 camera adapter such as https://www.ebay.com/itm/283686337025
Drill and tap it for 3 brass screws to work as a 40mm clamp ring, then add extension tubes.
You will also need a projection relay lens...
Image
This trinocular head unfortunately only has an "either-or" lever, where I can't look through the eye pieces and simultaneously get an image out the top. It would be great if I could replace this with a head that has a beamsplitter.
I am in the opposite camp; my EpiStar came with a beamsplitter trinocular head,
which IMO excessively compromises image contrast and brightness.
Swapping to a monocular head and eyetube clamp and using camera Live View
avoids the need for eyepieces with enough relief for eyeglasses..
I've read that the dovetails have similar radii between models, but the head also seems to have active optics at the bottom that may not be compatible with other models.
As an A.O. Series 10, 120 and Reichert EpiStar owner, I have read that Microstar IV heads are not fully compatible.
sadly it's difficult to find matching attachments that go in the optical path between the head and the objective
I guess that they are compatible with earlier A.O./Reichert attachments.
(I was hoping to hack in epi-illumination at some point).
Sadly, A.O.'s EPI-LUME attachment is only brightfield;
an EpiStar with matching objectives is needed for darkfield.
Darkfield infinity objectives with RMS threads are fairly rare.
Easier are M Plan infinity RMS objectives with enough working distance
to allow e.g. an LED on gooseneck:
Image
To get around lack of full color correction, consider an RGB 40mm LED halo:
Image
e.g. https://www.amazon.com/gp/product/B01FWX19QS

Scarodactyl
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Re: Beginner's Scope buying tips + polarization questions

#14 Post by Scarodactyl » Tue Feb 25, 2020 11:21 pm

blekenbleu wrote:
Tue Feb 25, 2020 6:52 pm
I am in the opposite camp; my EpiStar came with a beamsplitter trinocular head,
which IMO excessively compromises image contrast and brightness.
This is kind of odd. I use a Wild m400 for most of my photography, which has all three options (100/0, 0/100, 50/50) and visually I almost always can't tell the difference when I switch from 100% in the eyepieces to 50%. The eyes compensate so quickly it's incredible. The camera notices of course and needs longer exposures for requivalent brightness, but it really seems like it shouldn't have a gigantic effect on image quality if everything else is equal.

blekenbleu
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Re: Beginner's Scope buying tips + polarization questions

#15 Post by blekenbleu » Wed Mar 04, 2020 6:50 pm

Scarodactyl wrote:
Tue Feb 25, 2020 11:21 pm
I use a Wild m400 for most of my photography, which has all three options (100/0, 0/100, 50/50) and visually I almost always can't tell the difference when I switch from 100% in the eyepieces to 50%.
I suppose this is the difference between my arguably inadequate illumination and your more than adequate illumination.

blekenbleu
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Re: Beginner's Scope buying tips + polarization questions

#16 Post by blekenbleu » Wed Mar 04, 2020 7:39 pm

Returning to an original question:
BrianBurnes wrote:
Sat Feb 22, 2020 5:13 pm
- What kind of adapter do I need to attach a camera to the trinocular portion of the head?
FWIW, searching off and on for over 10 years has yet to find designated AO/Reichert photo relay/projection oculars.
Others, specifically Olympus PE 2.5x 125 and Nikon PLI 2.5, have 25 and 30mm diameter respectively, so need improvisation.
By suspending a DSLR with bellows over the microscope using an old copy stand, along with assorted extension tubes,
filter step-down rings and thread adapters, also rubber o-rings to centralize photo relay oculars in those extension tubes
and a light-blocking tube improvised from rolled card stock:
Image
... parfocal distances turn out to be ocular-specific.
For example, to usefully fill a full 35mm camera sensor,
here are distances from the (Canon 6D) lens mount to ocular shoulder:
PE 2.5x: 90mm
PLI 2.5: 115mm
.. and from the ocular shoulder to microscope head (Series 10, not Microstar IV)
PE 2.5x: 125mm
PLI 2.5: 133mm

Scarodactyl
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Re: Beginner's Scope buying tips + polarization questions

#17 Post by Scarodactyl » Wed Mar 04, 2020 11:12 pm

The PE should be 23mm. Nikon made both 23mm and 30mm versions of the PLI photo eyepieces. I would think their 2.5x PL (non-infinite) would be very similar since nikon CF and CFI eyepieces seem to be mostly compatible. All of those are non-compensating, though. It would probably be easier to go afocal with a pancake lens focused to infinity over a viewing eyepiece, since you'll at least get the eyepiece corrections.

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