Is there a color pattern or specimen-specific sample to differentiate a plan achromatic objective from another PLAN objective that is also FLUOR?
Thank you.
How to differentiate a PLAN FLUOR lens?
Moderators: rjlittlefield, ChrisR, Chris S., Pau
Re: How to differentiate a PLAN FLUOR lens?
Fluor objectives are generally pass more light in the UV portion of the spectrum - so you'd see the differences in UV microscopy.
In addition they often have higher numerical apertures (better resolution) at any given magnification and better color rendition. You might see a bit less color fringing at sharply defined edges in brightfield observations.
Most every maker will mark their objectives with an indication on the barrel they are plan and fluor-fluorite-fluar-fl etc. In at least one case, however, I recently managed to buy a cheap set of used "fluorite" objectives out of China or India where the barrel was stenciled plan fluor, but the optics inside were worse than ordinary. Decades ago, one could buy counterfeit Makita and Milwaukee power tools. Seems more recently there are even counterfeit -- or at least very poor quality -- generic plan fluor objectives??
In addition they often have higher numerical apertures (better resolution) at any given magnification and better color rendition. You might see a bit less color fringing at sharply defined edges in brightfield observations.
Most every maker will mark their objectives with an indication on the barrel they are plan and fluor-fluorite-fluar-fl etc. In at least one case, however, I recently managed to buy a cheap set of used "fluorite" objectives out of China or India where the barrel was stenciled plan fluor, but the optics inside were worse than ordinary. Decades ago, one could buy counterfeit Makita and Milwaukee power tools. Seems more recently there are even counterfeit -- or at least very poor quality -- generic plan fluor objectives??
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Scarodactyl
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Re: How to differentiate a PLAN FLUOR lens?
It isn't rigorously defined. They should be better color corrected than a plan achromat from the same line, but that's a pretty vague standard. They may also be more tranmissive but I don't think it's technically mandatory. Informally they often have more axial CA than lateral CA. Some objectives that would probably qualify (ie Nikon BD plan, olympus Neo SPlan) sometimes aren't labelled as such.
PeteM, any chance they were meant for a compensating system? I also got a generic 20x 'plan fluor' (out of a GE objective) which has terrible fringing on my Nikon scope. Oddly every other GE objective I've seen has been explicitly Nikon, and this one has m25 threads and is 60mm parfocal, but doesn't match any existing Nikon spec and again, terrible performance. Not sure what's up with it, unless it's a damaged copy.
PeteM, any chance they were meant for a compensating system? I also got a generic 20x 'plan fluor' (out of a GE objective) which has terrible fringing on my Nikon scope. Oddly every other GE objective I've seen has been explicitly Nikon, and this one has m25 threads and is 60mm parfocal, but doesn't match any existing Nikon spec and again, terrible performance. Not sure what's up with it, unless it's a damaged copy.
Re: How to differentiate a PLAN FLUOR lens?
Thanks for the reply, still please take a look at this coeloform in the Drive link below. PLAN FLUOR objectives used: 20X; NA 0.60 - 40X; NA 0.85
https://drive.google.com/file/d/1kpftnF ... sp=sharing
What do you think?
https://drive.google.com/file/d/1kpftnF ... sp=sharing
What do you think?