how to adjust the condenser
how to adjust the condenser
Hi everyone,
When I read about how to use a condenser, I often came across the advice:
Set the aperture diaphram lever of the condenser lens to "the same value as the NA of the objective lens".
However, my condenser is like this:
How would I use it in the best way then?
Thanks!
When I read about how to use a condenser, I often came across the advice:
Set the aperture diaphram lever of the condenser lens to "the same value as the NA of the objective lens".
However, my condenser is like this:
How would I use it in the best way then?
Thanks!
Re: how to adjust the condenser
Remove an eyepiece and peer down the empty tube … Adjust the diaphragm until it about seven-eighths fills the field of view, or until you are sure that no light is bouncing off the inner wall of the tube.
Make a note of the arbitrary number that Nikon has provided, for your future convenience.
MichaelG.
Make a note of the arbitrary number that Nikon has provided, for your future convenience.
MichaelG.
Too many 'projects'
Re: how to adjust the condenser
Having the condenser aperture a bit smaller that the objective NA gives the best xy resolution, but sometimes you want better depth of field which requires a smaller aperture. Abbe discusses this in his 1882 paper https://onlinelibrary.wiley.com/doi/10. ... .tb00190.x
Re: how to adjust the condenser
Agreed … but I consider the essential first-step is to set the maximum useable aperture.crb5 wrote: ↑Fri Dec 02, 2022 1:47 amHaving the condenser aperture a bit smaller that the objective NA gives the best xy resolution, but sometimes you want better depth of field which requires a smaller aperture. Abbe discusses this in his 1882 paper https://onlinelibrary.wiley.com/doi/10. ... .tb00190.x
MichaelG.
Too many 'projects'
Re: how to adjust the condenser
+1MichaelG. wrote: ↑Thu Dec 01, 2022 10:32 pmRemove an eyepiece and peer down the empty tube … Adjust the diaphragm until it about seven-eighths fills the field of view, or until you are sure that no light is bouncing off the inner wall of the tube.
Make a note of the arbitrary number that Nikon has provided, for your future convenience.
MichaelG.
Always good to have an identifiable starting point.
This is a link to the Abbe article on Dropbox: https://www.dropbox.com/s/bwfk3npzp94g4 ... e.pdf?dl=0
Note: No need to join Dropbox to download anything, close any window asking you to sign in - and then just click on the download button top left.
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)
Olympus E-P2 (Micro Four Thirds Camera)
Re: how to adjust the condenser
.75RR wrote: ↑Fri Dec 02, 2022 2:47 pmThis is a link to the Abbe article on Dropbox: https://www.dropbox.com/s/bwfk3npzp94g4 ... e.pdf?dl=0
Note: No need to join Dropbox to download anything, close any window asking you to sign in - and then just click on the download button top left.
Thanks for sharing that
… am I correct in believing that it is Part_1 of 2 ?
[ see his comment on p.302 ]
MichaelG.
Too many 'projects'
Re: how to adjust the condenser
You are, had missed that.MichaelG. wrote: ↑Fri Dec 02, 2022 3:43 pm.75RR wrote: ↑Fri Dec 02, 2022 2:47 pmThis is a link to the Abbe article on Dropbox: https://www.dropbox.com/s/bwfk3npzp94g4 ... e.pdf?dl=0
Note: No need to join Dropbox to download anything, close any window asking you to sign in - and then just click on the download button top left.
Thanks for sharing that
… am I correct in believing that it is Part_1 of 2 ?
[ see his comment on p.302 ]
MichaelG.
Here it is: https://www.dropbox.com/s/kjmc1h1kplbcl ... 2.pdf?dl=0
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)
Olympus E-P2 (Micro Four Thirds Camera)
Re: how to adjust the condenser
Thank you very much, MichaelG and 75RR.
Cheers,
Cheers,
Re: how to adjust the condenser
Just a thought on the markings on the Nikon Condenser. In the first picture, the aperture markings appear to be a linear scale (though I realize the diaphragm follows a square-law principle, double the aperture for 4 times the area). So on the Nikon condenser 30 should represent 1.25 and the lowest number on the scale (2?), to the lowest aperture (not sure what that is). So set up a ratio and make a similar linear scale corresponding to the numbers on the Nikon scale, 30=1.25, 25=..., 20=..., etc. Just a thought to get you into the aperture ballpark. (Very good articles, by the way!)