When in doubt, the first thing to do imo is topdle over to closeuphotography.com and have a look at Robert's testa. Looking under enlargers you'll see this as the first entry: https://www.closeuphotography.com/schneider-50mm-componon-s Mag range 1-4x, they cost about 50 bucks, and Robert even has a ...

The 2x apo is of very limited use thanks to its poor color correction. You'd get better results with the laowa or a cheap enlarger lens. On aps-c some 120mm tube lenses work. Iirc Ray has a couple of the 120mm gretags still for sale in the equipment exchange section, which is one of the best availab...

Fuether in the thread is an email address and a name along with some prices, which is probably better than going through alibaba. That said this is a new supplier to us and we don't know that every copy will be that good, so there is some caveat emptor.

The Nikon plan 10x is a surprisingly good performer for the price. There's also a Chinese mitutoyo clone 10x which is pretty good as recently revealed in this thread viewtopic.php?p=277553#p277553

Thanks for another entertaining, thorough and useful test. Shame it isn't better but they can't all be winners.

Other users' time could certainly be of more benefit elsewhere than with my questions, I see that. This is not a good way to think about this. The questions you're asking about lens design are interesting but I believe they fall pretty solidly outside the normal realm of photomacro knowledge. I per...

A used mitutoyo 20x would be towards the top of your budget but also probably the best option, if you're willing to test and possibly return any copy you get in case it's damaged. Secondary options would be elwd versions of any of the nikon or olympus metallurgical lines, or one of the better mituto...

What camera sensor size do you need to cover?

I'm curious too. I recently got a motic 20x that I need to test against my mitutoyo. I will say my mitutoyo has never struck me as particularly mediocre though. Still, I think the 50x/0.65 has my greatest attention. Halfway between a normal 50x and a 50x HR while maintaining good working distance. I...

Thanks, I made this. I would say the newer copy is on the same level as the Mitutoyo and clearly better than the older one. I brightened the Mitutoyo a little to not penalise the "Mitutoyo alternative". Are they really brandless? https://i.imgur.com/d4RkbGa.gif Nice! For on-microscope usage aps-c i...

Thanks, that's really interesting--too bad but good to know. I'll admit I've wondered if the 10x might be easier to copy. The motic and seiwa and even the badly delaminated usmc 10x objectives I have tried were all surprisingly good performers. Any chance you could possibly show an aps-c corner? It'...

Any time you see an objective specify a focal length like that it means they're infinity corrected (not counting antique objectives that list their effective focal length instead of magnification). The seiwa objectices are pretty good, though don't have the same coverage as a mitutoyo. There isn't a...

I should probably let someone who is more qualified answer--my only real education in optics was a two week internship in high school. I'll have another stab but I may not be entirely right here. On the microscope you have two metal-bladed iris diaphragms which are mechanically the same and only act...

As a maybe dumb model, to sharply cut off the field of view you'd need the iris to be in a plane of sharp focus. Where the iris sits it is, instead, so defocused that it fuzzes darkness evenly across the image instead. In microscopy you have two irises, the field iris which is in sharp focus and cut...

It depends. Some of the objectives have a big back element, but many don't--the mount is designed as a one size fits all solution after all, so if one objective needs the wide back element and they really want it in their lineup then every objective needs a big thread. Seiwa offers an rms version of...