Search found 19967 matches

by rjlittlefield
Wed Mar 27, 2024 7:49 pm
Forum: General Discussion Forum and Community Announcements
Topic: Software LoCA analysis
Replies: 1
Views: 34

Re: Software LoCA analysis

In quick search, the most relevant thing I found was https://smallpond.ca/jim/photomicrography/focusAnalyser/howto.html . It uses a web-based tool located at https://smallpond.ca/jim/photomicrography/focusAnalyser/index.html . I checked that the tool seems to be live, but did not attempt to test it ...
by rjlittlefield
Wed Mar 27, 2024 9:51 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Fossil diatoms in their natural habitat...
Replies: 2
Views: 58

Re: Fossil diatoms in their natural habitat...

Very interesting! This is definitely a case where I needed to see the full resolution image to make sense of what I'm seeing.

--Rik
by rjlittlefield
Tue Mar 26, 2024 9:53 pm
Forum: Equipment Discussions
Topic: understanding working distance
Replies: 3
Views: 130

Re: understanding working distance

As far as I understand internal focusing causes a shortening of the effective focal length but I think it somewhat more complex. Correct on both counts. In addition to changing the lens's focal length, internal focusing almost always changes the spacing of two "principal planes" from which optical ...
by rjlittlefield
Sun Mar 24, 2024 3:35 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: What camera adapter for trinoclear microscope
Replies: 9
Views: 198

Re: What camera adapter for trinoclear microscope

At present I see your photos are listed as "not downloaded yet." That said, your 1/1.8" sensor size should do OK with around a .5x reduction lens fitted ahead of a C-mount camera (if that's how your camera is mounted). That assumes your AmScope microscope doesn't already have a photo relay lens in ...
by rjlittlefield
Sun Mar 24, 2024 9:15 am
Forum: Equipment Discussions
Topic: Lens recomendation for film reproduction
Replies: 42
Views: 981

Re: Lens recomendation for film reproduction

Will be back in town in the later part of next week (attending annual pathology conference in Baltimore, MD). I will re-run same test using my old Micro Nikkor 55 mm and again 60 mm Nikkor lens at 5.6 and 8.0 and post some images... Enjoy your conference! I expect that a snapshot of your setup woul...
by rjlittlefield
Sat Mar 23, 2024 7:07 pm
Forum: Equipment Discussions
Topic: Lens recomendation for film reproduction
Replies: 42
Views: 981

Re: Lens recomendation for film reproduction

I can read that as saying that the Nikkor 60 mm lens was set on infinity focus ("minimal extension"), in which case the results make perfect sense. After the clarification I respectfully disagree... that it makes perfect sense... I agree with your disagreement. I had casually assumed that "minimal ...
by rjlittlefield
Sat Mar 23, 2024 4:56 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Lacking feature in Zerene and Helicon (but present in Affinity)
Replies: 2
Views: 172

Re: Lacking feature in Zerene and Helicon (but present in Affinity)

I would like to ask Rik: how complicated can it be to implement something similar in Zerene? I suppose, that what is needed is to detect the "bad/blurry" areas in DMAP and automatically replace them with PMAX, maybe on the fly, having PMAX already done before DMAP. But maybe this detection is alrea...
by rjlittlefield
Sat Mar 23, 2024 4:29 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Problem. "Fake rotation" of the object, with my Mitutoyo10x
Replies: 12
Views: 5604

Re: Problem. "Fake rotation" of the object, with my Mitutoyo10x

Thank you for the feedback.

I will be interested to read the new topic so that I can see what difficulties you are running into with stitching.

--Rik
by rjlittlefield
Sat Mar 23, 2024 4:11 pm
Forum: General Discussion Forum and Community Announcements
Topic: Loss of Robert OToole
Replies: 28
Views: 744

Re: Loss of Robert OToole

I thought I was prepared for this since Robert's earlier problems.

But it hits harder than I expected.

A remarkable man. I will miss him a lot.

--Rik
by rjlittlefield
Sat Mar 23, 2024 3:51 pm
Forum: General Discussion Forum and Community Announcements
Topic: Zeapon Motorized Micro 2Plus
Replies: 1
Views: 74

Re: Zeapon Motorized Micro 2Plus

Nothing in the ad looks very good for macro. They do not give any indication of step size, and the drive mechanism appears to be direct pull on a toothed belt. This device appears to be intended for use as a video/animation slider; note that all the illustrations show the camera either pointing off ...
by rjlittlefield
Fri Mar 22, 2024 2:12 pm
Forum: Equipment Discussions
Topic: Lens recomendation for film reproduction
Replies: 42
Views: 981

Re: Lens recomendation for film reproduction

60 mm Nikkor with PB-4 bellows; Nikon_60MM_BellowsPB-4.jpg 60 mm Nikkor without Bellows; Nikon_60MM.jpg Only difference is ~ 500 microns short with Bellows vs. Macro lens mounted to camera, very close to 1:1 mag. Nikon Z6II flange to sensor is 16.00 mm vs. on Nikon DSLR (D850) is 46.5mm..... Really...
by rjlittlefield
Thu Mar 21, 2024 8:11 pm
Forum: Equipment Discussions
Topic: State of high CRI COB lights in 2024? Current recs?
Replies: 4
Views: 250

Re: State of high CRI COB lights in 2024? Current recs?

One drawback of LEDs that I have been noticing is banding at high shutter speeds (1/500 and faster). Yeah, that's something I'm definitely curious to find out about. Heck, even if 1/500s is fast enough to get a non-shaky exposure given my system stability (or instability), or if I run into banding ...
by rjlittlefield
Tue Mar 19, 2024 6:11 pm
Forum: General Discussion Forum and Community Announcements
Topic: "naturefold" -- field photography with Laowa 2.5-5X and focus stacking
Replies: 4
Views: 158

"naturefold" -- field photography with Laowa 2.5-5X and focus stacking

There's a new channel on YouTube, https://www.youtube.com/@naturefold , with a young photographer named Alexis whose technique and results are masterful. He shoots in fast burst mode using a sort of lean-in technique, with heavily diffused flash. At first I was distracted by what appear to be severa...
by rjlittlefield
Mon Mar 18, 2024 7:14 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Hamuli
Replies: 13
Views: 470

Re: Hamuli

Bill and I have spent much time discussing his excellent images offline. I would like to add here a link to some external documentation that may clarify the structure. https://www.sciencedirect.com/science/article/abs/pii/S002219101930191X goes to "Structure, properties and functions of the forewing...
by rjlittlefield
Mon Mar 18, 2024 3:57 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: some scales
Replies: 140
Views: 14932

Re: some scales

Yes, like tiny waffles!

Doing a Google image search for pollen with waffle pattern produced one hit with a couple of very good matches:

GoogleImageForPollenWithWafflePattern.jpg

Unfortunately the full article is behind a paywall, and I don't care enough to pay.

--Rik