what is a "a two-channel condenser"?
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what is a "a two-channel condenser"?
I came across this reference whilst searching for another subject.
https://www.sciencedirect.com/science/a ... 2753901633
Whilst I am intrigued I have not purchased a copy of that part of the 1953 paper.
My guess is that there is nothing new here that it is not already being used by a member/reader on this board.
But what is a "a two-channel condenser"?
BR
John
https://www.sciencedirect.com/science/a ... 2753901633
Whilst I am intrigued I have not purchased a copy of that part of the 1953 paper.
My guess is that there is nothing new here that it is not already being used by a member/reader on this board.
But what is a "a two-channel condenser"?
BR
John
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Hi John,
The paper is very difficult to read as it uses almost none of the usual terms in microscopy; almost impossible to understand.
The author's point is that his design is NOT a two-channel condenser. He describes a two-channel condenser as follows:
"A two-channel condenser is generally used for optical staining of microscopical preparations. Staining occurs when light reaching the preparation at different angles is diffracted (after having passed through two differently coloured filters in the two channels). Two cones of rays of different colours are produced. One forms a solid centre, the second a surrounding hollow. In this way large angles are formed between rays of different wavelengths. Since smaller angles seem preferable in this connection, the two-channel principle has been abandoned."
"Optical staining" in this context is colour contrast in transmitted illumination.
I can't tell if the "two channels" are separate light paths or if they are created by field stops (both options were available at the time). However, it essentially sounds like a version of Rheinberg illumination. https://www.olympus-lifescience.com/en/ ... rheinberg/
Regards, Ichty
The paper is very difficult to read as it uses almost none of the usual terms in microscopy; almost impossible to understand.
The author's point is that his design is NOT a two-channel condenser. He describes a two-channel condenser as follows:
"A two-channel condenser is generally used for optical staining of microscopical preparations. Staining occurs when light reaching the preparation at different angles is diffracted (after having passed through two differently coloured filters in the two channels). Two cones of rays of different colours are produced. One forms a solid centre, the second a surrounding hollow. In this way large angles are formed between rays of different wavelengths. Since smaller angles seem preferable in this connection, the two-channel principle has been abandoned."
"Optical staining" in this context is colour contrast in transmitted illumination.
I can't tell if the "two channels" are separate light paths or if they are created by field stops (both options were available at the time). However, it essentially sounds like a version of Rheinberg illumination. https://www.olympus-lifescience.com/en/ ... rheinberg/
Regards, Ichty
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I agree with Ichty in that the "two channel condenser" sounds like condenser capable of providing Rheinberg illumination.
That Lambda condenser linked by JW sounds like an oblique condenser with iris that can be decentered. Though it is hard to tell for sure, without seeing it exact mechanism/optical diagram.
That Lambda condenser linked by JW sounds like an oblique condenser with iris that can be decentered. Though it is hard to tell for sure, without seeing it exact mechanism/optical diagram.
Selling my Canon FD 200mm F/2.8 lens
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Thanks to JW for providing the paper.Smokedaddy wrote:
Reading the caption to the image above I note that the condenser design incorporates "a built-in positive accessory lens between the relief and iris diaphragms. Apart from collimating the light beam, the lens brings the two diaphragms optically closer together, thus enhancing the quasi-three-dimensional (pseudorelief) effect in the images and improving viewing field homogeneity"
Has anyone seen a lens deployed between the diaphragm and a "oblique filter" in any previous condenser design or since?
Is the the "USP" which is giving more than just the oblique filter?
Has anyone any recommendations please for a lens that can be easily acquired for a DIY test of the arrangement?
Could it be the lens that is found on many abbe condensers for use with low power objectives as suggested in the paper?
Thanks
BR
John
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Reminds me of the Goerz condenser I worked on a while back:
http://www.photomacrography.net/forum/v ... php?t=8709
http://www.photomacrography.net/forum/v ... php?t=8709
Graham
Though we lean upon the same balustrade, the colours of the mountain are different.
Though we lean upon the same balustrade, the colours of the mountain are different.
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