My 'New' Chinese Nikon SMZ 645-alike Stereos

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Scarodactyl
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My 'New' Chinese Nikon SMZ 645-alike Stereos

#1 Post by Scarodactyl » Sat Oct 10, 2020 6:55 am

[See second post for a review of the nicer, more expensive model]
This week I finally got to try out a stereo microscope I've been wanting to have a look at for quite some time now. This model is rumored to be made by the same company in China that makes the SMZ 445/460 and most of the SMZ 645 for Nikon ('most of' because the eyepiece tube arrangement is different), allegedly Novel Optics. It's hard to say how many details of this are true--it's pieced together from somewhat sketchy sources like this https://microscopetalk.wordpress.com/mi ... -in-china/.
Edit: actually I just realized there are two almost-identical looking models with identical specs but different price points and the above was about the higher price point one, while the Amscope one is the lower price variant
This one is an Amscope-branded example, but almost everyone who sells Chinese stereo microscopes seems to carry this model and its little brother, a 445/460-alike which looks basically identical to the Nikon product.
Before this point I had briefly looked through one of the Unitron-branded 440-alikes, and was quite impressed. It performed just as good as my genuine SMZ-1b as far as I could tell. But the higher-end 645 clone called to me--its larger zoom ratio was appealing and unlike the genuine Nikon it has a trinocular option. Its specs are about ideal for gemscope usage, and indeed one of the better boutique gemscope makers uses this model as their in-house brand (edit: actually the model used is the more expensive one, not the one tested in this post): https://gemproducts.com/products
As they put it "The GemPro 850 is a new production head that is a close cousin to the Nikon SMZ-645. All internal parts are the same as are the eyepieces. The only difference is how the eyetubes work."
OK, so I finally found one in very good condition at a decent price and it came in today, pictured here on my Leic-alike test stand and with my dslr already attached:
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As you can see mounting a dslr was very easy. The top has a ~m26x0.5mm thread, so I printed an adapter to m42 and attached it with some spacers. The eye tubes do not deliver a big enough image to cover nikon CFUW eyepieces but the trinoc port covers APS-C with only a tiny bit of corner shading.

So, how is it? Mixed bag unfortunately, I suspect this copy was defective so take it with a grain of salt.
The first problem is really odd--the image is hard to converge. It takes effort to get the two to lay on each other in a way I've seen in some really old stereos but rarely in modern ones, never in good condition name brand ones. The alignment and parfocality across the zoom range seem perfect--the edge of each image lines up perfectly across the zoom range when looking at a flat subject. So what causes this issue is beyond me, but it's painful for me to look through the eyepieces for any length of time, and my brother (who is not a scope creep like me) noticed it immediately as well. Anyway it is likely defective in at least one way.
How's the image? Good for the price I'd say.
Afocal shots with my phone are not terrible:
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center
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corner (do circles have corners??)
But I think that my phone camera is tamping down just how bad the CA really is. Let's move to the DSLR shots:

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Min mag
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center
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cornerish (I took it a little bit away from the corner because of corner shading and highlight from the ring light).
CAs are more evident, particularly universal blue ghosting.
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Max mag
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centerish(I took it a bit away because of the hot spot)
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cornerish (I took it a little bit away from the corner because of corner shading and highlight from the ring light).
Lots of CA. Details aren't exactly tack sharp--focus might not be completely perfect but that's difficult without a coarse-fine stand.
Note the significant hot spot--the trinocular port inherently produces a lot of flare because it's shiny inside:
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You'd need to flock it or maybe add a baffle if you wanted to use direct projection, though that may not be too hard. Or it may be.
It's also possible my adapter is a little tilted, I'm not entirely sure how since the threads seem to have worked fine and definitely aren't cross-threaded, but I notice the corner shading is only on one side.
I also noticed some above-average astigmatism or coma on the left eye, which the camera doesn't draw from, when looking at phone pixels. In part of the FoV they just wouldn't quite resolve as diamond shapes.

Overall thoughts: These are surprisingly cheap, with the trinocular version on a stand and with eyepieces selling fo~380 dollars new from Amscope, less if you buy direct from China.

The design is clearly based on the SMZ645, but it is definitely not identical. Looking at the bottom I see both bottom lenses are connected directly to the bottom plate, while pictures of the SMZ645 show that one bottom lens is on a separate metal plate just like the earlier SMZ 2b/2t.

Mounting a dslr is super easy and it mostly covers aps-c, which is great. I'll try to remember to tweak my 3d file (m26 thread was a bit tight) and put it up on thingiverse. I might also try flocking and shooting again tomorrow. But it just isn't going to produce amazing photos.

I'm not sure why it hurts my eyes, maybe it wouldn't be bad for someone else? Likely this is not typical since it is a very popular head. If it didn't I would probably be saying this is a good option for someone who doesn't want to buy used, as the mag range is nice and third party nikon-compatible accessories are prevalent and pretty good in quality. But as is I just can't recommend it wholeheartedly. I'll admit I'm a bit disappointed, I went into this really positive and hoping to be as impressed as I was with the 445 clone.


Edit:corner shading on one side is because of how the trinoc port is shaped, no tilt. Flocking helps a bit but is probably more trouble than it is worth since clearance for the aps-c image is very tight.
Maybe this is a bad copy.
Last edited by Scarodactyl on Fri Mar 10, 2023 4:49 am, edited 2 times in total.

Scarodactyl
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Re: My 'New' Chinese Nikon SMZ 645-alike Stereo

#2 Post by Scarodactyl » Wed Mar 08, 2023 10:30 pm

I recently saw the preview of the GIA's new microscope at the Tucson gem show, and I noticed their scope had a similar but not identical head on it. This prompted a bit of research, and I have found there are at least four similar-looking versions of this pod. Note it's also possible that ones with the same cosmetic shell might have different optics inside though it seems a little less likely.
Variant 1 was reviewed in my first post, it is the cheapest variant.
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Next is variant 2, also sold by Scienscope, the GIA (at some point in the future), Unitron, gemological products. etc.
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Then another one, Variant 3 which also has a ridge on the back that you can't see here. Labomed sells this one. It is usually priced similar to variant 2.
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And finally Variant 4. This one is more expensive.
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1-3 have identical nominal specs, zooming from 8-50x with 10x/22 eyepieces. 4 has a larger zoom range from 6-50x and takes 10x/23mm eyepieces.

Anyway, variant 1 didn't do much for me, but I picked up a copy of variant 2 as a cheap pod for a project. This one is branded scienscope.
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Quick summary, unlike my copy of variant 1 I didn't find it uncomfortable to use or converge the image. The thread on top is the same 26x0.5mm thread as variant 1, and it also direct projects onto aps-c with a bit of shading on one side. I took some shots of a similar chip.
Min mag, center and corner crops.
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max mag, center and corner crops
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Suffice to say it performs better than variant 1 with better resolution, no coma, no flare(!!) and better CA control, it's not super amazing compared with a top end stereo but it's a very solid routine scope and it's always nice to be able to direct project. Micro 4/3 would probably be a more favorable format as expected by the 22mm field number.
There is one other issue I noticed. The fixed 50/50 trinocular split is accomplished by a half mirror and at minimum mag it shows ghosting on highlights which merge back into the real image as you zoom in.
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apochronaut
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Re: My 'New' Chinese Nikon SMZ 645-alike Stereos

#3 Post by apochronaut » Thu Mar 09, 2023 5:17 pm

These all seem to be similar conceptually but that concept is an old tried and true one going back many years. The heads all seem to be of slightly different shapes with the trinocular port shoulder slightly different too. I would be surprised if they didn't come from different factories and from different design teams. There are a lot of microscope factories in China.

PeteM
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Re: My 'New' Chinese Nikon SMZ 645-alike Stereos

#4 Post by PeteM » Thu Mar 09, 2023 8:27 pm

Stephen, do you have any idea of the mechanical build quality of these scopes?

I've seen older Chinese zoom scopes with similar side handle zoom operation (Scienscope, Omax, AmScope, etc.) end up sloppy (poor bearing surfaces, cracked plastic housings, loss of parfocality) after a few year's use, and a few times with the central plastic zoom gear broken (and unavailable as a replacement part). In contrast, something like an old Wild M3Z will still be going strong after decades of use.

Scarodactyl
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Re: My 'New' Chinese Nikon SMZ 645-alike Stereos

#5 Post by Scarodactyl » Fri Mar 10, 2023 12:31 am

apochronaut wrote:
Thu Mar 09, 2023 5:17 pm
These all seem to be similar conceptually but that concept is an old tried and true one going back many years. The heads all seem to be of slightly different shapes with the trinocular port shoulder slightly different too. I would be surprised if they didn't come from different factories and from different design teams. There are a lot of microscope factories in China.
Yeah, I think you are right, similar to the several olympus sz4045-alikes. And who knows how many might have the same shell and different internals? There's another style shell which is clearly copied from an SZ61Tr which is available from various sellers in several different zoom ratios too, clearly different internals despite identical exteriors.
PeteM wrote:
Thu Mar 09, 2023 8:27 pm
Stephen, do you have any idea of the mechanical build quality of these scopes?

I've seen older Chinese zoom scopes with similar side handle zoom operation (Scienscope, Omax, AmScope, etc.) end up sloppy (poor bearing surfaces, cracked plastic housings, loss of parfocality) after a few year's use, and a few times with the central plastic zoom gear broken (and unavailable as a replacement part). In contrast, something like an old Wild M3Z will still be going strong after decades of use.
Good question, and of course hard to know. The used scienscope seems fine aside from some splits in the rubber gaskets around the oculars reminiscent kd those faced by b&l sz scopes (anyone know where to get replacements?) I wouldn't pay the bolioptics retail asking price for one, much less Unitron or Scienscope, but I paid a lot less for my used copy than a trinocular M3Z would cost (not to mention it came with olympus eyepieces worth a good portion of what I paid), and it's also a lot easier to integrate into a larger system since it's a standard 76mm head. And much as it pains me to say it, an m3z with a normal nonplan achro 1x might actually perform worse optically.
I suppose overall I would call it a reasonable option for someone who needs a stereo microscope but is unwilling to buy anything used.

PeteM
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Re: My 'New' Chinese Nikon SMZ 645-alike Stereos

#6 Post by PeteM » Fri Mar 10, 2023 12:56 am

One partial fix for the B&L gaskets is to use a couple of arch punches (OD and ID) and thin foam or rubber gasket material. Even an scrapped tire tube might work for the material.

Having ventured inside some of the older stereo microscope clones, no matter how closely they resemble the real thing (Olympus, Nikon) on the outside, there were numerous differences, mostly shortcuts, on the inside. Some (from Motic as an example) are sensible to allow a lower price. Others are likely to lead to eventual failure (e.g. cheap plastic zoom gears and guides) or difficulty should they get out of alignment.

With CNC lens grinding the defacto standard worldwide, I agree the Chinese, Indians, etc. are making decent optics. The differences seem to be in things like coatings, assembly, parcentering, parfocality, and QC as the scopes are headed out the door.

What I like about the old Wild stereo scopes is that their mechanisms are often so well designed and built (and easy to service) that they can perform like new decades later. I might add that the successor company, Leica, has made some over-complicated mechanisms. Their ergo heads, for example. Same over-complications common with Zeiss. Beautiful mechanisms, but zillions of tiny bearings, an assortment of screw sizes, jigs needed for disassembly, and so on.

As you say, the newest optics often have slightly wider and flatter fields, sometimes fewer aberrations.

Scarodactyl
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Re: My 'New' Chinese Nikon SMZ 645-alike Stereos

#7 Post by Scarodactyl » Fri Mar 10, 2023 7:01 pm

All I can really say is that this one has held up to some amount of use and is still fine, all for less than half the price that a trinocular port for an m3z would typically cost. In the long run of course a serious microscopist is going to want something like the all metal, all-badass Wild experience--that's why I have an M10 after all--but I figure it's worthwhile to have some information out there about these cheaper models too. There isn't that much hard third party info out there about most stereo scopes, even the name brand ones. The closest we might get are comments from dealers like LMscope which aren't always very informative.

PeteM
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Re: My 'New' Chinese Nikon SMZ 645-alike Stereos

#8 Post by PeteM » Fri Mar 10, 2023 9:41 pm

I agree - these can offer good value for the price.

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