100x oil vs. 100x dry objectives

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aristharcus
Posts: 4
Joined: Mon Jan 11, 2021 1:43 pm

100x oil vs. 100x dry objectives

#1 Post by aristharcus » Wed Jan 13, 2021 7:53 pm

I'm starting to thing about my next scope. I must say I hate oil immersion lenses: I must put so much care in order to not contaminate the scope that I end up not enjoying the experience.

Since I have no experience with 100x dry objectives, could anyone tell his/her experiences about resolution and sharpness? Which lens works better?
Thanks in advance!

apochronaut
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Re: 100x oil vs. 100x dry objectives

#2 Post by apochronaut » Wed Jan 13, 2021 10:27 pm

Dry objectives cannot achieve high N.A. performance. Some really good ones get to .95 but anything over about .85 must be able to correct for minute differences in cover slip and sample thickness. They are actually more finicky to use than oil immersion objectives. High mag. dry objectives are expensive and you have to be carefull because most of them are corrected for no cover slip.
Oil immersion is not a big problem once you get your feet wet with it and the resolution results are worth it.

You could try water immersion. I have some 1.10 and 1.15 N.A. for some infinity scopes.

Greg Howald
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Re: 100x oil vs. 100x dry objectives

#3 Post by Greg Howald » Thu Jan 14, 2021 5:32 am

I have achieved suitable dry images with a 100x oil objective by backing off the condenser a considerable distance. Play with it. Contrast increases as you lower the condenser. I have been known to cheat using mineral oil instead of cedar oil . I find it easier to work with. R.I. of about 1.45-7.
Greg

aristharcus
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Joined: Mon Jan 11, 2021 1:43 pm

Re: 100x oil vs. 100x dry objectives

#4 Post by aristharcus » Thu Jan 14, 2021 7:29 pm

I'll try today to lower the condenser and see how the 100x oil objective works in such a "dry fashion". Anyway, maybe I must learn to use oil as a natural microscopy technique. Maybe buying a 60x objective can be an alternative and to forget all that 100x headaches.

An useful link: https://www.leica-microsystems.com/scie ... esolution/

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75RR
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Re: 100x oil vs. 100x dry objectives

#5 Post by 75RR » Thu Jan 14, 2021 10:19 pm

aristharcus wrote:
Thu Jan 14, 2021 7:29 pm

Anyway, maybe I must learn to use oil as a natural microscopy technique.
In my view not every subject merits high magnification and resolution, but when they do, it is well worth the 10 extra minutes you spend at the end of a session cleaning off the immersion oil.
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)

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KurtM
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Re: 100x oil vs. 100x dry objectives

#6 Post by KurtM » Fri Jan 15, 2021 2:22 am

Somehow this reminds of something the dentists says when I balk at having some procedure done: "when it hurts bad enough you'll be back".

When you want to see whatever it is you're trying to see bad enough, you'll deal with the oil.
Cheers,
Kurt Maurer
League City, Texas
email: ngc704(at)aol(dot)com
https://www.flickr.com/photos/67904872@ ... 912223623/

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