MicrobeHunter.com Microscopy Forum

Thanks for the detailed reply. So my amature interpretation is that BF specimens can be viewed on a phase system but their could be some spherical aberration, and that could be corrected by using BF objectives. Is that correct?

Thanks,
henryr

yep. the phase condenser when used without the phase diaphragms will work great.

Thanks again. But to make sure I understand, you wrote diaphragms. Is diaphragms an alternate term for objectives?

Thanks,
henryr

Diaphragm is the correct term for the phase "rings" installed in the phase condenser housing. Sometimes the word annulus or the plural annuli is used. They are diaphragms of various sizes. My reference was to using the open port which is additionally always supplied in a phase condenser housing for BF observations.

Thanks. And if I finally understand correctly what you have described, I can't think of a reason why I would buy a BF scope if buying a PC scope and several BF objectives gives me the capabilities of PC and BF.

That is a good point. I can't think of any phase contrast condenser housings that cannot also be used for standard BF and in most systems ( B & L excluded), the phase condenser easily removes to be replaced with a more highly colour corrected oil achromat for use with planfluorite or planapo BF objectives, if required. You have to have a condenser housing/mount anyway, so why not a phase capable one that can easily accomodate, various BF systems or even fluorescence for that matter. With a little ingenuity , even DF could be done.
When/if buying used though, it is always wise to educate one's self about a considered purchase and the various models that were produced. Some phase condensers ( few) are L.W.D. condensers and although they might be adequate with the proper phase objectives, they also might be a limiting with standard working distance B.F. objectives. You then, would have to also acquire a standard working distance B.F. condenser to screw or slide in when B F. is desired.

After reading so many positive posts about AO infinity scopes I'm thinking of parting with my Leitz SM-M and Dialux. Would AO infinity objectives provide improved viewing?

Thanks,
henryr?

Dialux seems like a pretty competent platform and Leitz seems to have had an extensive phase line at one time or another I don't think there would be a big advantage in switching