23mm diameter 10x/22 eyepieces (!)

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Scarodactyl
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23mm diameter 10x/22 eyepieces (!)

#1 Post by Scarodactyl » Wed Aug 05, 2020 11:22 pm

I had a pleasant surprise today. I ordered a pair of Chinese 10x/22 eyepieces with a 23mm barrel a while back and they just arrived. I imagine a lot of people here have seen these at one point or another, but at ~50 bucks a pair it seems both too expensive to try on a lark and too cheap to be any good. But they would be a big improvement for my DIY macroscope design, so I thought what the hell and gave them a try.
This is what they look like:
https://i.imgur.com/cXQWK2z.png
Standard look for Chinese eyepieces, though a bit fat for 23mms. I tried them out in my recently-assembled Nikon optiphot and was quite pleased with the results. The FoV is definitely wider, and there don't seem to be any particular issues with corrections.

Sorry for the bad test images, it's been a busy day. These are quickly backlit shots of a dusty slide (this optiphot has a wafer holder so doing a proper test will be a bit more of a pain) taken with my phone camera through the eyepieces.
Nikon CFWN eyepiece:
Image
generic 10x/22 eyepiece:
Image
If anything the generic eyepieces seem to show a bit less CA without any particular issues with curvature that I can see. The FoV is decidedly wider on the Chinese pair, coming out to around 21.9 with some quick relative measurements though there is some edge shading. The CFWN have a reddish ring around them as has been noted many times before.

Overall, the wider FoV is nice and the image looks good to the eye.

A much better test would be of a higher-contrast subject with better positional control on the camera, and preferably with a planapo objective. But if you're not looking to use these afocally I think they'd definitely qualify as 'good enough'.

I will say, this is a nice little perk of a non-or-minimally-compensating system. That being said, I kind of wonder what usecase these eyepieces would have outside of older Nikon compounds or an oddball project like the DIY macroscope above. Who made these, and why? And why did the big brands not make 10x/22s themselves when 23mm eyepieces were in vogue? Maybe this has just gotten a lot easier with modern supply chains and computer design methods?

Zuul
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Re: 23mm diameter 10x/22 eyepieces (!)

#2 Post by Zuul » Wed Aug 05, 2020 11:53 pm

Scarodactyl wrote:
Wed Aug 05, 2020 11:22 pm
And why did the big brands not make 10x/22s themselves when 23mm eyepieces were in vogue? Maybe this has just gotten a lot easier with modern supply chains and computer design methods?
Maybe they weren't interested in (or capable of) designing all of their objectives to be aberration free all the way to 22mm.

Scarodactyl
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Re: 23mm diameter 10x/22 eyepieces (!)

#3 Post by Scarodactyl » Thu Aug 06, 2020 12:04 am

I suppose it was easier to just offer the UWF head for those objectives corrected out that far, and keep it at 20 for the others--that is a fair decision, the UWF head is pretty fantastic.

Side-note, I tried one out on my Bausch and Lomb SZ7, and as expected it does not perform so well there. They are parfocal with Nikon eyepieces but struggle to achieve parfocality with b&ls, and the FoV does not appear wider vs the normal B&L WF 10xes.

apochronaut
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Re: 23mm diameter 10x/22 eyepieces (!)

#4 Post by apochronaut » Thu Aug 06, 2020 12:25 am

I have recently had some email conversations, if that is an acceptable term for a daily question answer session, with a couple of Chinese microscope factory reps. The product line coming out of the factories appears to be streamed , with what generally shows up badged for the mass marketers and house brands, lets call stream 1, where the budget is first and foremost. Stream 2, is the more professional line of equipment but generally it also costs.. Your 22mm eyepieces are probably dippng into that stream 2, maybe on an interface between the 2 but at 50.00 are certainly attractively priced. A quote I got for 25mm/30 were 160.00, if my memory serves me. Those are for an NIS60 system. There are slso 23/30 that are configured on an AO pattern.

If the images you provided are relatively accurate, if any thing, the 22mm eyepieces are as good or better.

Zuul
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Re: 23mm diameter 10x/22 eyepieces (!)

#5 Post by Zuul » Thu Aug 06, 2020 2:38 am

apochronaut wrote:
Thu Aug 06, 2020 12:25 am
There are slso 23/30 that are configured on an AO pattern.
How would the average person be able to spot this? (No, Phil, you aren’t an average person in regard to microscopy.)

apochronaut
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Re: 23mm diameter 10x/22 eyepieces (!)

#6 Post by apochronaut » Thu Aug 06, 2020 11:09 am

Zuul wrote:
Thu Aug 06, 2020 2:38 am
apochronaut wrote:
Thu Aug 06, 2020 12:25 am
There are slso 23/30 that are configured on an AO pattern.
How would the average person be able to spot this? (No, Phil, you aren’t an average person in regard to microscopy.)
Commonly available Chinese microscopes are made in patterns. Once you become familiar with those patterns , you see that there are only a small number of them and the public vendors of them use tiny alterations in basically unsubstantial features to present differences in their sales literature. Inexperienced consumers see these differences , many of them cosmetic as "real" , so there is great trade and sometimes debate about the relative merits of two or more microscopes that do essentially the same thing. It makes for interesting reading , primarily regarding the psychology of being presented with too many choices, or rather having the capacity to entertain them. It is often quite painful to witness people labouring over these illusory differences and making well reasoned choices about nothing.
Outside of that, there are some more proprietary designs,. which are not often seen represented in the mass market or if they are, as la creme de la creme. They are marketed mostly domestically and fill a void between the mass market stuff pumped out of a conduit , and the better and vebry expensive microscopes they import for their own use professionally. One wouldn't think Chinese pathologists are using an Amscope.
These proprietary designs are picked up and branded ( or not) by various higher end companies that deal in professional lab materials. You can tell they are different from the get go. I have known about this for quite a few years now, so occasionally I will see a component from one of them around for sale and if the price is right I will buy it and test it, to see what it is made of. So, to answer your question, I bought an objective and trialled it.
You are obviously intrigued by the thought of putting a 23mm f.o.v. on an AO microscope? It is an intrigueing thought and I have looked into it. Yes, you could directly use the 45mm parfocal objectives on an AO stand but there wouldn't be much advantage because they are planachros but good ones. I have not determined so far if any planfluorites were made for that system.
In order to take advantage of the f.o.v., you would have to put AO objectives on one of the Chinese stands or make a radical adaption to a Microstar IV or Diastar or even a 10 and fit one of the Chinese made 23mm trinoculars .

Element 56
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Re: 23mm diameter 10x/22 eyepieces (!)

#7 Post by Element 56 » Thu Aug 06, 2020 6:33 pm

apochronaut wrote:
Thu Aug 06, 2020 11:09 am
Commonly available Chinese microscopes are made in patterns. Once you become familiar with those patterns , you see that there are only a small number of them and the public vendors of them use tiny alterations in basically unsubstantial features to present differences in their sales literature.
This is also true of Chinese made woodworking and metal working machinery too. The stuff sold by Harbor Freight, Grizzly, Enco and others supposedly comes from one of only handful of manufactures. It is said that there's differences in the more expensive versions of the same machines such as a particular lathe sold by Micro Mark compared to one looking like and having the same specs as one from Harbor Freight. Personally I do my best to avoid all if it whenever I can afford to do so and even sometimes when I really can't. I have had bad experiences with the very few pieces of Chinese metal working equipment I have bought and I've read of cases where people ended up completely rebuilding brand new machines to get them working right.

With this in mind I often wondered about the quality of Chinese microscopes. Are they ready to go right out of the box or do they need torn down, cleaned and re-lubricated? I see post's here that indicate the optics are okay but I wonder about the mechanics of those instruments.

Kirby

Scarodactyl
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Re: 23mm diameter 10x/22 eyepieces (!)

#8 Post by Scarodactyl » Thu Aug 06, 2020 7:02 pm

It varies. I've gotten a lot of used Chinese stereos that are subtly misaligned (and in a way that makes me think they left the factory that way). On the other hand I've tried some Chinese stereos I really, really liked (mostly the Wild clones I harp on, but some of the Nikon "clones" by novel optics have a great image too [they apparently make Nikon's lower end stereos so they're not really just clones]).

apochronaut
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Re: 23mm diameter 10x/22 eyepieces (!)

#9 Post by apochronaut » Thu Aug 06, 2020 10:45 pm

The microscopes I am talking about , are around 2200 to 2800 U.S. f.o.b. the factory, so they step outside the norm for Chinese scopes. Yet, when fully equipped, they can present performance specs. well beyond the stencil types, hawked on the net.

Scarodactyl
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Re: 23mm diameter 10x/22 eyepieces (!)

#10 Post by Scarodactyl » Wed Aug 19, 2020 11:06 pm

So, here's another wrinkle. I posted about these on photomacrography (where I first heard about them) and a poster there mentioned they are actually ultrawide eyepieces stopped down by the 23mm adapter. That seemed farfetched, but when I unscrewed the bottom part and held the top up to my Nikon UW head it did give a very wide FoV. I just finished printing a 30mm adapter for them to try more formally:
Image
Image
This worked well and I got some pretty bad test photos with my cell phone. These were taken on my optiphot, using an epi illuminator which doesn't cover the UW FoV evenly, but they do the job I think. There is edge shading on the generic eyepieces and a little distortion, but CA performance is actually a bit better, though this isn't particularly visible to the eye.
CFUW:
Image
Generic:
Image
CFUW:
Image
Generic:
Image

In short, for 50 bucks and a bit of printing I think this is a really great option, and would probably work well on stereo scopes as well. Whoever is making these is delivering some crazy performance per dollar!

apochronaut
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Re: 23mm diameter 10x/22 eyepieces (!)

#11 Post by apochronaut » Fri Aug 21, 2020 1:16 am

These seem very much like the 25/30 eyepieces most notably being offered by Bestscope for their tier 2 research offerings. The 30mm version are 160 f.o.b. the factory or a very close broker. Your adaption looks great ; I guess the slightly fuzzy field stop is due to there not really being one?
The Bestscope 30mm eyepieces are for an NIS 60 scope, so Nikon formated. Since the factory(ies) that produce those Bestscopes also produce Olympus formated stands, perhaps the 22m versions were aimed for Olympus. Maybe they did not sell , so were remainderd.. 52.00/PR. is below the cost of production , even in China.

apochronaut
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Re: 23mm diameter 10x/22 eyepieces (!)

#12 Post by apochronaut » Mon Sep 14, 2020 4:27 pm

I bought a pair of them. As Scarodactyl pointed out they do represent remarkable value. I have only trialled them in a series 4 so far, where they are about as good as the native eyepieces at and near the axis and slightly superior off axis. The objective range of the 4 are pre- plan and some colour compensation and a little field flattening is accomplished in a common apochromatic compensating lens above the nosepiece. The native eyepieces in the system are quite neutral but also very W.F. for the era.
These Chinese eyepieces appear to have a little compensation built in for peripheral colour and also a little field flattening, in order to help their complementary production objectives out a little, I would guess. Well they help out the 60 year old AO achromats as well, giving a 22mm well corrected and slightly flatter field than they have with the factory # 146 10X W.F.. They have turned my series 4 phase system, currently sporting 17 different phase objectives, into even a better microscope system than it already was.
The only criticism I can level at them: two actually, are that since they are maxing the field in a 23.2mm tube out , they use the inside of the ocular tube as a field stop. It is a little rough and not quite crisp. They are both focusing eyepieces and as such, may have been originally been made for a phoropter. They focus stiffly and cannot be focused without holding the eyepiece from rotating while focusing. Once focused, though, the diopter only is necessary.
Great that you pointed them out Scarodactyl!

EYE C U
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Re: 23mm diameter 10x/22 eyepieces (!)

#13 Post by EYE C U » Mon Sep 14, 2020 5:13 pm

I HAVE BOUGHT 18 AND 22...18 SEEMS BETTER FOR ME..THEY ARE MY EVERY DAY EYEPIECES NOW...THE RIGHT SIZE EYECUP HELPS TOO.

Scarodactyl
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Re: 23mm diameter 10x/22 eyepieces (!)

#14 Post by Scarodactyl » Tue Sep 15, 2020 1:46 am

I'm glad you like them Apo! I know you've looked through many more types of microscope eyepieces than most anyone--makes me glad I bought a few extra pairs for myself as well!

hans
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Re: 23mm diameter 10x/22 eyepieces (!)

#15 Post by hans » Wed Sep 16, 2020 7:10 am

Thanks for the pointer, Scarodactyl. I bought one to experiment with for afocal camera coupling thinking it might be optically similar to the Reichert Austria WP 10x/20 I asked about a few weeks ago where the higher exit pupil vs. the Reichert 181 is helpful and the curved eye lens surface might help with the "hot spot" problem common in afocal setups. The exit pupil is indeed a bit higher, roughly 22 mm vs. 19 mm for the 181. Similar mechanical complaint as apochronaut -- the focus adjustment is a bit gritty feeling with an excessive amount of viscous, sticky lubricant applied. (So much that every time you screw it in then back out the exposed part with diopter scale comes out with lube all over it.) I started to take it apart just to see if I could clean out some of the lube but one thing led to another and I ended up taking it all the way apart out of curiosity. This one does not look "Plössl-type" as the poster in the photomacrography.net thread said. In the photo the elements are ordered field-to-eye going from left to right:
  • positive meniscus with concave surface facing into the microscope
  • thick slightly-convex doublet with strongly-curved internal interface (seen with violet laser pointer) but low optical power relative to the two single lenses
  • positive meniscus with concave surface facing the eye
Does not look very similar to any of the standard types listed on Wikipedia or various telescope sites.
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apochronaut
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Re: 23mm diameter 10x/22 eyepieces (!)

#16 Post by apochronaut » Wed Sep 16, 2020 5:39 pm

A lot of telescope enthusiasts get kind of dumb ass around microscope eyepieces, due to the strong association between telescope performance and the type of eyepiece employed. As a result, astronomical eyepiece terminology gets tossed around related to microscope eyepieces when it isn't really relevant. Microscope companies diverged from utilizing classic named eyepiece designs somewhere around Kellner in general and only a few companies named eyepieces as such.
The arbiter of microscope performance is the objective and since it is changeable in both focal length and various corrections, the eyepiece has to do a group of different duties than a telescope eyepiece has to, so designs are more often proprietary on a microscope and don't relate that well to telescope eyepiece designs or performance.

hans
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Re: 23mm diameter 10x/22 eyepieces (!)

#17 Post by hans » Wed Sep 16, 2020 6:31 pm

apochronaut wrote:
Wed Sep 16, 2020 5:39 pm
Microscope companies diverged from utilizing classic named eyepiece designs somewhere around Kellner in general and only a few companies named eyepieces as such. The arbiter of microscope performance is the objective and since it is changeable in both focal length and various corrections, the eyepiece has to do a group of different duties than a telescope eyepiece has to, so designs are more often proprietary on a microscope and don't relate that well to telescope eyepiece designs or performance.
Any idea what sort of system this design would have been done for originally? While looking around I noticed there are some Chinese "WF10X/23" with 30 mm tube that look almost identical to these and very similar to some Zeiss 30 mm tube 10x/23 eyepieces like:
https://www.ebay.com/itm/193324391167
https://www.ebay.com/itm/202748651798

apochronaut
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Re: 23mm diameter 10x/22 eyepieces (!)

#18 Post by apochronaut » Thu Sep 17, 2020 1:25 pm

The Chinese planned economy is quite good at maximizing resources. As Scarodactyl showed, the tube extension can easily be exchanged for a 30mm version and a field stop of any diameter one chooses could be installed up to at least 25mm.
Looks like they are used in the tier 2 Chinese scopes that carry the NIS60 M25 objective series modelled after Nikon's system , as 25 mm f.o.v. eyepieces with 30mm bores. At least the exterior looks the same. The same model of microscope has a default eyepiece of 22mm with a 30mm bore and it looks the same slso . The same factory also produces microscopes that are based on the Nikon CFI R.M.S. system They probably are used there too.
It is entirely possible that there is a factory somewhere making the same eyepiece with various field stops, to suit the marketing requirements of the dealers, maybe even Nikon too . The perception of value would be based on field diameter and focusing capability and from an economic standpoint it makes more sense to kick out a one size fits all eyepiece that can be made to seem less expensive by virtue of it's field size than produce a bunch of entirely different designs. A non focusing version with identical optics could also be made and it could be pitched as a less expensive design. The f.o.b. price of the 25/30mm focusing version is 160.00/pr. Probably 125.00 or so if you were a distributor buying a lot of them.
They are not quite neutral, evidenced by Scarodactyls photo evidence, where they correct a little for the slight bit of lateral ca even Nikon's own eyepieces don't. Yes there is lateral ca evidence .in the Nikon only photo. Is CFI a bit of marketing hype? In my own tests , they provide a bit of helpful peripheral correction with older objectives that were never intended to be stretched to 22mm. No doubt the objectives they are intended for need that a little bit of help too. It is easier to do that in the eyepiece than anywhere else because of the relativel slight curvatures involved and broad lenses......and cheaper to effect it in multiple mass produced eyepieces, than in multiple objectives.

There is a 23/30mm eyepiece out there for another higher end Chinese microscope with a different infinity corrected system . The old AO 34mm system in fact but it usees 45mm parfocal objectives. It is a 10 or 15 year old design but is still being produced. It has a convex eye lens. Unusual and not consistent with the AO eyepiece designs.

EYE C U
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Re: 23mm diameter 10x/22 eyepieces (!)

#19 Post by EYE C U » Thu Sep 17, 2020 4:42 pm

"Any idea what sort of system this design would have been done for originally? While looking around I noticed there are some Chinese "WF10X/23" with 30 mm tube that look almost identical to these and very similar to some Zeiss 30 mm tube 10x/23 eyepieces like"

MAY AS WELL COPY SOMETHING GOOD...my zeiss eyepieces that came all scratched up would have been junked but i found some 4.99 18mm ones that the glass swapped over perfectly..and they work great ;-)

hans
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Re: 23mm diameter 10x/22 eyepieces (!)

#20 Post by hans » Thu Sep 17, 2020 6:56 pm

apochronaut wrote:
Thu Sep 17, 2020 1:25 pm
They are not quite neutral, evidenced by Scarodactyls photo evidence, where they correct a little for the slight bit of lateral ca even Nikon's own eyepieces don't. Yes there is lateral ca evidence .in the Nikon only photo.
Agreed, reaching up into the periphery of the image plane with a soot-blackened dental pick I see more red/blue fringing with the WF10X/22 than with a 181. I thought the doublet in the middle was interesting, reminiscent of the color correcting doublet in the 400 heads in the sense that the internal interface has much stronger curvature than the external surfaces and its contribution to the total optical power of the eyepiece is relatively small.
apochronaut wrote:
Thu Sep 17, 2020 1:25 pm
There is a 23/30mm eyepiece out there for another higher end Chinese microscope with a different infinity corrected system . The old AO 34mm system in fact but it usees 45mm parfocal objectives. It is a 10 or 15 year old design but is still being produced. It has a convex eye lens. Unusual and not consistent with the AO eyepiece designs.
I noticed the "WF10X/23" 30 mm I mentioned were temporarily discounted to the too-good-to-be-true price of $11 each with free shipping so I ordered a pair. In the photos they look identical to this WF10X/22 just with 30 mm tube instead of 23 mm, but obviously the ones you are talking about are different optically if they have a convex eye lens. Will see what I end up with. I want a pair of 30 mm eyepieces anyways to put in an old Unitron ZSM for my daughter to use.

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