Other Uses for a Bertrand Lens?

Here you can discuss all microscopy-related accessories and equipment (microtomes, filters...)
Post Reply
Message
Author
Sure Squintsalot
Posts: 81
Joined: Mon May 16, 2022 3:44 pm

Other Uses for a Bertrand Lens?

#1 Post by Sure Squintsalot » Wed Jun 29, 2022 1:23 am

I'm fully aware of how to use a Bertrand lens on a petrographic microscope. Apparently, they are also found on biological scopes. Why?

What are the other uses are there for these lenses and do they reside in the same place on bio-scopes as they do on petro-scopes?

Importantly, how are they used in imaging biology?

apochronaut
Posts: 5270
Joined: Fri May 15, 2015 12:15 am

Re: Other Uses for a Bertrand Lens?

#2 Post by apochronaut » Wed Jun 29, 2022 1:47 am

Diaphragm alignment is one main use ; phase diaphragm alignment but also iris diaphragm centering. A Bertrand lens offers a good view of anything going on at the rear focal plane of the objective.

BramHuntingNematodes
Posts: 1421
Joined: Tue Jan 21, 2020 1:29 am
Location: Georgia, USA

Re: Other Uses for a Bertrand Lens?

#3 Post by BramHuntingNematodes » Wed Jun 29, 2022 1:48 am

I have heard you can use it as a phase telescope to examine your diaphragms
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

BramHuntingNematodes
Posts: 1421
Joined: Tue Jan 21, 2020 1:29 am
Location: Georgia, USA

Re: Other Uses for a Bertrand Lens?

#4 Post by BramHuntingNematodes » Wed Jun 29, 2022 1:49 am

(I may have heard it from apo)
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

MichaelG.
Posts: 3483
Joined: Mon Apr 10, 2017 8:24 am
Location: NorthWest England

Re: Other Uses for a Bertrand Lens?

#5 Post by MichaelG. » Wed Jun 29, 2022 6:12 am

Hallimond’s patent is available here:
https://worldwide.espacenet.com/publica ... cale=en_EP

… and for completeness, we should probably look at Amici’s original concept
Ref. __ https://www.encyclopedia.com/science/di ... trand-lens

I will post a link here when/if I find a good description

MichaelG.

.

Meanwhile [if I may be permitted a small digression] this might be of interest:
https://rruff.info/doclib/MinMag/Volume_18/18-83-45.pdf
Too many 'projects'

Post Reply