Hi everyone:
I thought you might be interested in a brief video clip I made to show the 3D structure of a diatom. The frustule was photographed with an unusual objective: an Anoptral Contrast objective by Reichert. These lenses provide a nice sepia toned background to the movie.
http://www.youtube.com/watch?v=zq_qlIGo6to
Enjoy,
Brian
3D rendering of a diatom: a video
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What is anoptral contrast?-
Brian Matsumoto
- Posts: 37
- Joined: Wed Aug 11, 2010 2:57 pm
The following is a shoot from the hip answer as I have not read very many papers on Anoptral contrast.
It appears to me that it is a variant of phase contrast. Wilska, who discovered and published the technique used the soot from a candle flame to coat the rear lens of his objective lens. He carefully remove portions of the soot and created a brown toned annulus. He then fabricated a annular stop to fit beneath his condenser and this provided a ring of light that passed through the brown-toned ring in the objective. This is similar to the design employed in many Zernicke phase contrast systems.
However, Wilska and Reichert (who manufactured Anoptral commercially) made some incredible claims about the performance of Anoptral contrast. One thing when phase contrast objectives are used in phase contrast, there is a demonstrable drop in resolution in comparison to brightfield. The resolving power of phase contrast objectives is proportional to the diameter of their phase annulus: Anoptral lenses had an unusually large diameter phase rings and as a general rule these oil immersion lenses can outperform the oil immersion Zernicke phase objectives.
I provided a link to Wilska's letter to Nature (1953). Sadly, I never read the article illustrated with plates and only started reading and using Anoptral contrast in my retirement. Now that I no longer have ready access to the journals it is harder to read the older articles. As a student, I read about the technique and always wanted to see just what it could do. Now 40 years later, as a retiree, I have the time to play with it.
http://www.micromagus.net/microscopes/l ... ature.html
Below is a nice biography of Wilska.
http://www.feps.org/fileadmin/files/Alv ... 1-1987.pdf
Brian
It appears to me that it is a variant of phase contrast. Wilska, who discovered and published the technique used the soot from a candle flame to coat the rear lens of his objective lens. He carefully remove portions of the soot and created a brown toned annulus. He then fabricated a annular stop to fit beneath his condenser and this provided a ring of light that passed through the brown-toned ring in the objective. This is similar to the design employed in many Zernicke phase contrast systems.
However, Wilska and Reichert (who manufactured Anoptral commercially) made some incredible claims about the performance of Anoptral contrast. One thing when phase contrast objectives are used in phase contrast, there is a demonstrable drop in resolution in comparison to brightfield. The resolving power of phase contrast objectives is proportional to the diameter of their phase annulus: Anoptral lenses had an unusually large diameter phase rings and as a general rule these oil immersion lenses can outperform the oil immersion Zernicke phase objectives.
I provided a link to Wilska's letter to Nature (1953). Sadly, I never read the article illustrated with plates and only started reading and using Anoptral contrast in my retirement. Now that I no longer have ready access to the journals it is harder to read the older articles. As a student, I read about the technique and always wanted to see just what it could do. Now 40 years later, as a retiree, I have the time to play with it.
http://www.micromagus.net/microscopes/l ... ature.html
Below is a nice biography of Wilska.
http://www.feps.org/fileadmin/files/Alv ... 1-1987.pdf
Brian
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Brian Matsumoto
- Posts: 37
- Joined: Wed Aug 11, 2010 2:57 pm
My apologies John for neglecting to reply to you in the previous email. Your query arrived just as I was composing my reply to another query.
Here is the technical information:
Leitz Ortholux
Leitz Heine condenser
Reichert Anoptral contrast achromat 30X N.A. 0.65
Camera: Sony A77 mounted on a Nikon F adapter with 2.5X Olympus eyepiece
Brian
Here is the technical information:
Leitz Ortholux
Leitz Heine condenser
Reichert Anoptral contrast achromat 30X N.A. 0.65
Camera: Sony A77 mounted on a Nikon F adapter with 2.5X Olympus eyepiece
Brian
Hi Brian
Thanks so much. I have a 1950's Ortholux (for refurbishment), a Heine and a set of Reichert Anoptrals (and a Zetopan which is also up for refurb).
I acquired this kit bit by bit and thought it might work out based on research. I am glad that with your demonstration that I will now so enthusiastically set to get this up and running.
Thanks
John
Thanks so much. I have a 1950's Ortholux (for refurbishment), a Heine and a set of Reichert Anoptrals (and a Zetopan which is also up for refurb).
I acquired this kit bit by bit and thought it might work out based on research. I am glad that with your demonstration that I will now so enthusiastically set to get this up and running.
Thanks
John
-
Brian Matsumoto
- Posts: 37
- Joined: Wed Aug 11, 2010 2:57 pm
John,
The regular Heine condenser has made the Ortholux my favorite tool for phase contrast microscopy. So far, there has not been any phase objective that I could not use on that stand.
Two nights ago, I had a chance to play with a Zeiss pancratic phase condenser which does the same thing. I had hoped to compare the Reichert lenses to the Zeiss and Leitz Phaco objectives, but sadly that condenser limited its annulus diameter to what would just fill a Zeiss oil immersion phase plate. It could not be enlarged to work with the higher resolution Reichert or Leitz Phaco objectives.
It is fascinating to try this mix and match approach to microscopes. Sometimes it does not work, but when it does, it provides a new way of viewing specimens.
Brian
The regular Heine condenser has made the Ortholux my favorite tool for phase contrast microscopy. So far, there has not been any phase objective that I could not use on that stand.
Two nights ago, I had a chance to play with a Zeiss pancratic phase condenser which does the same thing. I had hoped to compare the Reichert lenses to the Zeiss and Leitz Phaco objectives, but sadly that condenser limited its annulus diameter to what would just fill a Zeiss oil immersion phase plate. It could not be enlarged to work with the higher resolution Reichert or Leitz Phaco objectives.
It is fascinating to try this mix and match approach to microscopes. Sometimes it does not work, but when it does, it provides a new way of viewing specimens.
Brian
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carlos.uruguay
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- Location: Uruguay - Montevideo - America del Sur
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carlos.uruguay
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Brian Matsumoto
- Posts: 37
- Joined: Wed Aug 11, 2010 2:57 pm
-
carlos.uruguay
- Posts: 5358
- Joined: Thu Feb 23, 2012 8:05 pm
- Location: Uruguay - Montevideo - America del Sur
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