Search found 6 matches
- Sun Apr 21, 2024 9:08 pm
- Forum: Illumination Techniques
- Topic: Darkfield Illumination
- Replies: 17
- Views: 1216
Re: Darkfield Illumination
Conrady (1912) made use of Abbe's theory of image formation, which as he noted was the only theory sufficiently well developed at that time. Abbe was mostly using off-axis pencil beams investigating diffraction effects. Using that approach Conrady presented his result that the condenser must have no...
- Thu Apr 11, 2024 7:21 pm
- Forum: Microscopes and optics
- Topic: Averaging condenser and objective numerical aperture when predicting resolution
- Replies: 49
- Views: 5478
Re: Averaging condenser and objective numerical aperture when predicting resolution
Conrady was one of the greats in optical design (lots of geometry and algebra) but it would not be until the French physicist Duffieux put fourier optics on a sound foundation that image formation with its complexities could be analyzed. Even then its surprising how long it took for his discoveries ...
- Mon Apr 08, 2024 5:17 pm
- Forum: Microscopes and optics
- Topic: Averaging condenser and objective numerical aperture when predicting resolution
- Replies: 49
- Views: 5478
Re: Averaging condenser and objective numerical aperture when predicting resolution
Hans, In the first post of this thread you wrote: "Following Martin (1966, p. 230) a comparison of resolution under different conditions is given using K: K = x⋅NA/λ where x is the interval of a grating, or separation of two objects, ..." You did not give an explicit reference to Martins text but it...
- Sat Apr 06, 2024 1:18 am
- Forum: Microscopes and optics
- Topic: Averaging condenser and objective numerical aperture when predicting resolution
- Replies: 49
- Views: 5478
Re: Averaging condenser and objective numerical aperture when predicting resolution
Hi hans, Thanks for the discussion. I also have collected papers over the years including the ones you referenced earlier. The Abbe rule averaging NAobj & NAcond has never seemed to be a useful one. At best it is a first approximation only. Given the range of specimens, stained and unstained, diffra...
- Wed Mar 06, 2024 10:45 pm
- Forum: Illumination Techniques
- Topic: Condenser Alignment.
- Replies: 17
- Views: 2667
Re: Condenser Alignment.
Apo, a splendid contribution as well as thought provoking. Like Hobbyst46 I have Zeiss scopes fitted with the same AchApl 1.4 phase condensers. Never thought of centering lens of condenser proper. However below the condenser lies an auxiliary lens that does have centration control which I have never...
- Sat Jan 20, 2024 3:51 am
- Forum: Microscopes and optics
- Topic: Condenser parfocality
- Replies: 1
- Views: 516
Condenser parfocality
Got an optics question I cannot answer without your guys help. In the Zeiss Optical Systems guide which can be found at: https://www.science-info.net/docs/zeiss/ZeissOpticalSystems.pdf on pg. 89 for Z-type condensers (of which I both a flip top 0.9 NA and an ach-apl 1.4 NA) it begins with this state...