Chinese Wild M3 Clone: It's pretty good! [With comparison to mz6]

[Scarodactyl]

PS. One key part of Scarodactyl's previous response that I do not understand - - " Using the m400 like that it is the same as a Nikon infinity head (down to a partially compativly dovetail). Not much point to that imo.")

Somehow missed this message. My point was just that the M400 series heads are optically the same as a Nikon infinity head, with a 200mm tube lens without compensations built into it. They do have the advantage of being built with a coarse-fine focus mount built in, but if you want to use compound objectives primarily it probably makes more sense to just assemble a microscope from parts meant for that, both financially and with how the a final product will work. Among other things the M400 series are also hard to find compatible eyepieces for, while the default ones have a low FN of only 21 (the optics can easily cover 26.5mm if you don't have the intermediate illuminator attached).

[Scarodactyl]

OK, here's some worse news. The M3 clone did pretty well, but followup tests have suggested it vignettes in the eyepieces when a photo tube is attached, which is odd.

I also finally did a comparison between my M7 and my motic M700z, a nice-looking copy. Though it looks quite good to the eye, the M700z doesn't hold a candle to the M7 when viewed in the less forgiving eye of the camera. For this test I put the scopes on a simple 25mm stand, attached an LED ring light and took pictures of a silicon wafer at low and high mag, refocusing as needed to get the best view in the corner and center (this ended up only mattering for the m700z). I used a surgical beamsplitter with a 250mm tube lens attachment which does direct projection onto the sensor, giving a similar FoV to the eyepieces.
It's pretty dire, I feel a bit bad for saying it looked similar to the eye. This isn't a strongly controlled test but I don't think it matters.
Real M7 Low mag:

center:

corner:


M700z low mag:

center:

corner:


Real m7 high mag:

center:

corner:


M700 high mag:

center:

corner:




Long story short the image in the M7 is brighter, has better contrast and obviously higher resolution, while the M700z also suffers from some coma/astigmatism in the corners and doesn't have as flat a field.
Caveats: positioning isn't super carefully controlled, but it didn't end up mattering with how strong the signal is. Both of these units are used with cosmetic issues, so it is possible this copy of the m700z isn't quite up to snuff.
It's still a decent starter scope and I like it a lot better than bottom of the barrel chinese stereos I have tried, but it just can't stand up to the real M7 (which, to be fair, is a hard hitter in its price range).

[jfiresto]

... The M3 clone did pretty well, but followup tests have suggested it vignettes in the eyepieces when a photo tube is attached, which is odd.

What Field Number eyepieces, and which binocular head and photo tube? My Wild M3 (made ca. 1980) still does not vignette with Zeiss 10X/23 eyepieces, the standard 45° head and an old, low profile, slanted back Wild 376788 photo tube. I reckon the tube adds ca. 30mm to the infinity optical path.

[jfiresto]

If anyone is curious what Motic's clone of the Wild M7A looks like, there is a fairly complete Motic M-700Z on auction at the moment.

[MicroBob]

In case someone wants to bid on this ebay-offer: Have a look at the picture of the corroded front lens. Whatever has cause this was close to the whole microscope and I would suspect that there is more damage.

[jfiresto]

Those spots might come off, but if I were the seller I would have tried to clean the objective: to assess its condition and prevent possible disappointment.