Search found 224 matches

by ploum
Mon Aug 22, 2022 8:41 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Photo of Ploum
Replies: 228
Views: 136434

Re: Photo of Ploum

Phenakite Better https://www.geoforum.fr/uploads/monthly_2022_08/photo0119.jpg.42ba7e85bca3dadaea8f3b9666467d02.jpg https://www.geoforum.fr/uploads/monthly_2022_08/photo0119.thumb.jpg.8598f4d9ed23369afba7903c5a2df9ad.jpg Clinoclase Better https://www.geoforum.fr/uploads/monthly_2022_08/photo0117.jpg...
by ploum
Sat Aug 20, 2022 10:28 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Photo of Ploum
Replies: 228
Views: 136434

Re: Photo of Ploum

colohank wrote:
Sat Aug 20, 2022 9:48 am
Not just great lighting, Ploum, but also superb specimen preparation. Very clean! Do you treat those minerals to an ultrasonic bath?
acid, water spray, scouring cream..... all is possible ;)
by ploum
Sat Aug 20, 2022 5:53 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Photo of Ploum
Replies: 228
Views: 136434

Re: Photo of Ploum

Some news https://www.geoforum.fr/uploads/monthly_2022_08/photo0097.thumb.jpg.d39aa36feedd1270a3459a7ab5f7dee2.jpg Better : https://www.geoforum.fr/uploads/monthly_2022_08/photo0097.jpg.a6bae7b1cd1add5c99fce249926b3c75.jpg https://www.geoforum.fr/uploads/monthly_2022_08/photo0095.thumb.jpg.cebf29524...
by ploum
Wed Dec 22, 2021 1:19 pm
Forum: Equipment Discussions
Topic: How good are alternatives (clones) to Mitutoyo lenses
Replies: 111
Views: 18537

Re: How good are alternatives (clones) to Mitutoyo lenses

Hello, I received the 2x 0.06. Jerry has done his job well and the transaction is fine. However my system unfortunately does not support this lens ... It is unsuitable for an FF and the image circle is small. The quality of the image is also inferior to what I would expect. A well-made componon will...
by ploum
Sun Nov 14, 2021 12:43 pm
Forum: Equipment Discussions
Topic: Mitutoyo M Plan APO HR 5X 0.21 Test Results
Replies: 149
Views: 16498

Re: Mitutoyo M Plan APO HR 5X 0.21 Test Results

Great links :) from Rik :)
by ploum
Sun Nov 14, 2021 7:33 am
Forum: Equipment Discussions
Topic: Mitutoyo M Plan APO HR 5X 0.21 Test Results
Replies: 149
Views: 16498

Re: Mitutoyo M Plan APO HR 5X 0.21 Test Results

I noticed that two pixels is not enough for a diffraction spot. The contrast is too low. It would be interesting if Robert likes the tests that he does tests with a USAF HR test chart that does groups 9 and 10. The reconstruction according to the focal length of the tube lens should allow me to find...
by ploum
Sat Nov 13, 2021 9:40 am
Forum: Equipment Discussions
Topic: How good are alternatives (clones) to Mitutoyo lenses
Replies: 111
Views: 18537

Re: How good are alternatives (clones) to Mitutoyo lenses

Hello,

for forum it's a 20 % discount i suppose ?

I have written for try a 2x 0.06 :)

Fred
by ploum
Wed Nov 10, 2021 10:56 pm
Forum: Equipment Discussions
Topic: Mitutoyo M Plan APO HR 5X 0.21 Test Results
Replies: 149
Views: 16498

Re: Mitutoyo M Plan APO HR 5X 0.21 Test Results

Thanks @ploum for your insights, need to learn more about all of these and what you are saying. Long time ago, there was a long discussion about something similar and eventually, I "had" (ie, no choice in face of facts) to agree with Rik who was trying so hard to teach us that fact. During that dis...
by ploum
Wed Nov 10, 2021 7:18 am
Forum: Equipment Discussions
Topic: Mitutoyo M Plan APO HR 5X 0.21 Test Results
Replies: 149
Views: 16498

Re: Mitutoyo M Plan APO HR 5X 0.21 Test Results

Here two objective APO PLAN on the same systeme (sensor, lens tube...)

What is the best ?

Image
by ploum
Wed Nov 10, 2021 6:41 am
Forum: Equipment Discussions
Topic: Mitutoyo M Plan APO HR 5X 0.21 Test Results
Replies: 149
Views: 16498

Re: Mitutoyo M Plan APO HR 5X 0.21 Test Results

I have an FF 36 Mpix sensor, and a 10X NA 0.25 objective. Can you tell me how to construct graphs like yours, for myself, for this combination? --Rik https://www.geoforum.fr/uploads/monthly_2021_11/image.png.166e95de8066d803c20a4f2880939700.png https://www.geoforum.fr/uploads/monthly_2021_11/image....
by ploum
Wed Nov 10, 2021 2:15 am
Forum: Equipment Discussions
Topic: Mitutoyo M Plan APO HR 5X 0.21 Test Results
Replies: 149
Views: 16498

Re: Mitutoyo M Plan APO HR 5X 0.21 Test Results

Yes i do when i finish my work :) All this to conclude that if I get a more contrasted image with a lens with a higher numerical aperture it is simply because the sensor can be in subsampling which means that the system will analyze lower frequencies through the objective and therefore give a more c...
by ploum
Wed Nov 10, 2021 12:31 am
Forum: Equipment Discussions
Topic: Mitutoyo M Plan APO HR 5X 0.21 Test Results
Replies: 149
Views: 16498

Re: Mitutoyo M Plan APO HR 5X 0.21 Test Results

I don't write an article here.... I must write that in French and for private books. An article need 150 pages.... and i have not time to do in english... I give some ideas for people. In fact i can use 0.55 um or 0.56 um for lentgh wave of green colore. it's not very important for me :) And if i do...
by ploum
Tue Nov 09, 2021 9:51 pm
Forum: Equipment Discussions
Topic: Mitutoyo M Plan APO HR 5X 0.21 Test Results
Replies: 149
Views: 16498

Re: Mitutoyo M Plan APO HR 5X 0.21 Test Results

wow, this thread has grown a lot, learning more here . . OK, back to crazy world :D I'm happy for that. In fact, those who want to understand my curves will understand everything they need to upgrade their equipment and better adapt their sensor and their objectives! In fact if we can optimize in t...
by ploum
Tue Nov 09, 2021 9:40 pm
Forum: Equipment Discussions
Topic: Mitutoyo M Plan APO HR 5X 0.21 Test Results
Replies: 149
Views: 16498

Re: Mitutoyo M Plan APO HR 5X 0.21 Test Results

0.61*lambda/0.21 Another example... Let me assume that for smallest FOV, you have somehow chosen LP/mm to match the Rayleigh criterion. Then the MTF of the objective for that LP/mm will be only about 9% = 0.09, as it always is for Rayleigh. From that, I conclude that the overall system MTF = object...
by ploum
Tue Nov 09, 2021 12:04 pm
Forum: Equipment Discussions
Topic: Mitutoyo M Plan APO HR 5X 0.21 Test Results
Replies: 149
Views: 16498

Re: Mitutoyo M Plan APO HR 5X 0.21 Test Results

Usual math. Rayleygh criterion, sampling on the sensor, MTF, minimum sampling of the sensor at 2.5-3 pixels per LP .... https://www.geoforum.fr/uploads/monthly_2021_11/image.png.b5df806e005f6d95dc69c1a1ded23862.png https://www.geoforum.fr/uploads/monthly_2021_11/image.png.b5df806e005f6d95dc69c1a1ded...