Swift/Motic lenses

Everything relating to microscopy hardware: Objectives, eyepieces, lamps and more.
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paulg269
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Joined: Wed Apr 12, 2023 5:26 pm

Swift/Motic lenses

#1 Post by paulg269 » Mon May 29, 2023 7:02 pm

Hi, I recently bought a Swift Stellar 1, does anyone know where I can purchase an infinity 20x lens as I find this size far more use than the 100x oil immersion lens. Thanks in advance.

PeteM
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Joined: Tue Dec 06, 2016 6:22 am
Location: N. California

Re: Swift/Motic lenses

#2 Post by PeteM » Mon May 29, 2023 7:53 pm

Generic 20x objectives (45mm DIN parfocal) from eBay should work. Some of the Swift Stellar 1 scopes used 160mm finite objectives, so double-check that yours takes the infinity versions. If your other objectives have "160" printed on them, you need finite objectives. EBay is a source for those as well.

I've bought a few of the 20x infinity generic objectives and have found there are at least two versions of the plan achromats. One has a comparatively smaller lens at the end with a black surround, and the other has about 5mm of glass showing and a longer working distance (but the same .40 claimed numerical aperture). The one with a black surround is a bit sharper. I don't know if this is typical, if it is stopped down a bit, or ??

The Motic 20x infinity with a chrome barrel (not quite as wide a field as the Motic infinity ones with fat black barrels) would be about double the cost new, with greater assurance of good quality.

In terms of sharpness, I'd rate the generic 20x with the larger front element as acceptable for your Swift, with the slight plus of more working distance, the generic 20x with the black surround as slightly sharper, the Motic as slightly sharper still, and an Olympus UIS 20x infinity (also suitable) as yet another tiny step better. Any of those, used and in good shape, could be options for you.

Again, be sure it's infinity objectives you already have at the other magnifications.

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