Search found 30 matches
- Tue Aug 23, 2016 6:16 am
- Forum: Equipment Discussions
- Topic: how do you find entrance pupil on Mitutoyo objectives?
- Replies: 15
- Views: 4907
Rik, Really interesting indeed. If i look into my MTTY5 i can see your point, but the 10x behaves somewhat different and i can see a sharp circular boundary over a wide range of distances to the eye that i considered to be the entrance pupil. I made a quick image (just placed the objective on a piec...
- Mon Aug 22, 2016 10:58 am
- Forum: Equipment Discussions
- Topic: how do you find entrance pupil on Mitutoyo objectives?
- Replies: 15
- Views: 4907
Hi Rik, i used the method with a macro objective with shallow dof and made sharp images of the entrance and the exit pupil using a white background to determine the pupilary magnification. That is to my knowledge a standard procedure. Your question makes me thinking. Making the lens telecentric mean...
- Sat Aug 20, 2016 9:56 am
- Forum: Equipment Discussions
- Topic: how do you find entrance pupil on Mitutoyo objectives?
- Replies: 15
- Views: 4907
The entrance pupil should be separated from the front focal plane by f/m_p, where m_p is the pupilary magnification of the objective. With f = 20 mm (=200 mm/10) and m_p = 0.67 (determined from the ratio of the two pupilary diameters) the entrance pupil should be shifted by 29.8 mm with respect to t...
- Sat Oct 03, 2015 10:13 am
- Forum: Macro and Micro Technique and Technical Discussions
- Topic: Setup of Ploum
- Replies: 92
- Views: 44174
Frederic, thank you for confirming this number. If this is the case you have probably built a two-sided telecentric system in your first stage, as the distance between the two elements appears to equal the some of the focal lengths. Placing the diaphragm in the common focal plane makes the system tw...
- Fri Oct 02, 2015 11:59 pm
- Forum: Macro and Micro Technique and Technical Discussions
- Topic: Setup of Ploum
- Replies: 92
- Views: 44174
- Fri Oct 02, 2015 9:15 am
- Forum: Macro and Micro Technique and Technical Discussions
- Topic: Setup of Ploum
- Replies: 92
- Views: 44174
- Fri Oct 02, 2015 7:08 am
- Forum: Macro and Micro Technique and Technical Discussions
- Topic: Setup of Ploum
- Replies: 92
- Views: 44174
Frederic did i get this right: 1. Distance between the Raynox and the 200 mm lens is 18 cm on the average? You change this distance for stacking by 2 cm, so it varies from 17 cm to 19 cm? 2. What is the distance between the 200 mm lens and the microsocope objective (or enlarger lens) In your drawing...
- Wed Sep 30, 2015 7:49 am
- Forum: Macro and Micro Technique and Technical Discussions
- Topic: Setup of Ploum
- Replies: 92
- Views: 44174
In my first contribution to this thread is gave some formulas that describe a lens combo if the distance between the two stages is smaller than the sum of the focal lengths. I consider these still to be correct. In the analysis given i assumed however that the second stage taken alone produces a rea...
- Wed Sep 30, 2015 7:44 am
- Forum: Macro and Micro Technique and Technical Discussions
- Topic: What happens when e > f1 + f2
- Replies: 11
- Views: 5575
Thank you for the information Frederic - a distance of 8 cm between Raynox and sensor cannot give a real image of the second stage. In my investigation in the original thread (Ploums setup) i assumed that the second stage alone produces a real image. In order to keep up with the new information conc...
- Tue Sep 29, 2015 12:38 pm
- Forum: Macro and Micro Technique and Technical Discussions
- Topic: What happens when e > f1 + f2
- Replies: 11
- Views: 5575
- Tue Sep 29, 2015 8:39 am
- Forum: Macro and Micro Technique and Technical Discussions
- Topic: What happens when e > f1 + f2
- Replies: 11
- Views: 5575
Hello Frederic, i like your mineral images very much - they are really beautiful. I have to admit that i did not understand the first of your sketches, explaining your setup. I think i understand the second case - with a separation e of the two lenses that is smaller than the sum of the two focal le...
- Mon Aug 10, 2015 12:10 am
- Forum: Macro and Micro Technique and Technical Discussions
- Topic: Setup of Ploum
- Replies: 92
- Views: 44174
Hello Rik, i do completely agree - the problem with Frederics setup is, that you cannot make m2 small if you want large magnification m AND reasonable step sizes for the stacking procedure. Large values of m2 requires the MTTY to be operated far from m2=0 - the point it has been designed for. So: no...
- Sun Aug 09, 2015 11:52 pm
- Forum: Macro and Micro Technique and Technical Discussions
- Topic: What happens when e > f1 + f2
- Replies: 11
- Views: 5575
Very interesting Rik - i know the (afocal) case f1+f2=e which is widely employed in two-sided telecentric optics used for measuring purposes (Schneider-Kreuznach e.g. produces a series of such lenses - and has published a nice tutorial on telecentric optics, that might be of interest to others). I o...
- Sat Aug 08, 2015 8:02 am
- Forum: Macro and Micro Technique and Technical Discussions
- Topic: Setup of Ploum
- Replies: 92
- Views: 44174
Rik - i think there are several restrictions to the accessible range of e - but if e gets larger than f1+f2 then total f becomes negative - i'm not sure that my calculations apply to that case (to my knowledge imaging with f1+f2 < e is usually described as a succession of two imaging processes with ...
- Thu Aug 06, 2015 3:24 am
- Forum: Macro and Micro Technique and Technical Discussions
- Topic: Setup of Ploum
- Replies: 92
- Views: 44174
Rik - thank you for your excellent demonstration, i’m glad to here that the formulas worked. I completely agree with your conclusions, and just cite from an email that i sent to John (dolmadis) yesterday in the afternonn. „You get really small shifts of the object plane even from a shift of the two ...