Re: Koehler illumination in conoscopic observation

"Richard J Kinch" <kinch@xxxxxxxxxxx> wrote in message
news:Xns99F72199C1902someconundrum@xxxxxxxxxxxxxxxxx
NoSpam writes:

I forgot to raise a point: Is opal glass or ground glass the
choice for a diffuser?

http://www.luminitco.com/

Dear Dr. Kinch,

Most interesting! I have looked at Luminit's pdf on Light
Shaping Diffusers (LSDs) and found a description of such
a diffuser which exactly fits my needs.

A pertinent image and text can be found under "Homogenized
Light". The advantage of their diffusers seems to be that they
cause very little loss of light.

There is of course a question not answered by this brochure:
Is the probably very high price of Luminit's LSDs justified by
the gain they make in light throughput compared to cheap
ground glass?

Kevin is right: modern scopes all use light diffusers to hide the
filament structure of the illuminating lamp. I wonder whether
Luminit like diffusers are used in these scopes.

Another interesting fact seems to be that centering screws for
the condenser no longer are needed and provided. I wonder
whether it has been found that the mounting can be manufactured
accurately enough to avoid the centering mechanism altogether.
Fact is that modern and expensive scopes no longer offer what
is known as Koehler illumination.

Thnanks for your interest.

GR.


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