Search found 129 matches

by bralex
Tue May 02, 2023 6:47 am
Forum: Equipment Exchange
Topic: fs: LEICA HR PlanApo 5x/0.50 LWD WD 19mm
Replies: 14
Views: 4102

Re: fs: LEICA HR PlanApo 5x/0.50 LWD WD 19mm

What I've done with one other oddball lens was to take a piece of UHMW HDPE (Ultra-high Molecular Weight High-Density Polyethylene; a soft, heavy plastic) and drill it out to just a bit smaller than the outside diameter of the threads, then just screw in the lens. The plastic is soft enough to defor...
by bralex
Sun Feb 05, 2023 10:49 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Teleconverters in macro
Replies: 43
Views: 4615

Re: Teleconverters in macro

Harald wrote:
Fri Feb 03, 2023 8:25 am
There is more to the macro/micro world than minerals.
Blasphemer!
by bralex
Wed Jan 25, 2023 7:29 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Teleconverters in macro
Replies: 43
Views: 4615

Re: Teleconverters in macro

That will also be effective f/25 as seen by the sensor. (Feff = m/(2*NA), m=14, NA = 0.28) With most modern sensors that will be well into diffraction territory, so expect some softness when pixel-peeping. --Rik Rik, is there a book you can point me too that discusses this type of calculation and t...
by bralex
Thu Jan 19, 2023 9:20 am
Forum: Equipment Discussions
Topic: Mitutoyo 20x/0.42 compared with workalike Hoopuo 20x/0.45
Replies: 8
Views: 2366

Re: Mitutoyo 20x/0.42 compared with workalike Hoopuo 20x/0.45

I'm very interested in this as well - I want a 20x but the $2000+ price tag concerns me!
by bralex
Wed Feb 16, 2022 4:03 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Rutile, Psuedobrookite from Paramount Canyon, NM
Replies: 5
Views: 922

Re: Rutile, Psuedobrookite from Paramount Canyon, NM

Though there could be a few ilmenites mixed in (and anatase for that matter), both the elongated orange and the blocky crystals tested as the niobium-rich variant of rutile. The striations are pretty distinctive, and, though not particularly visible in these photos, they are deep red rather than tru...
by bralex
Wed Feb 16, 2022 9:04 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Rutile, Psuedobrookite from Paramount Canyon, NM
Replies: 5
Views: 922

Re: Rutile, Psuedobrookite from Paramount Canyon, NM

These are rutile only - though the individual crystals in the center remind me more of anatase. My estimated size for those is 0.02 mm across, using the ruler tool in photoshop!
16858 rutile copy for pmac.jpg
by bralex
Wed Feb 16, 2022 9:02 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Rutile, Psuedobrookite from Paramount Canyon, NM
Replies: 5
Views: 922

Re: Rutile, Psuedobrookite from Paramount Canyon, NM

This one is a crop from a larger pic, so a bit fuzzier. I need a 20x lens!
16837 rutile a copy for pmac.jpg
by bralex
Wed Feb 16, 2022 9:01 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Rutile, Psuedobrookite from Paramount Canyon, NM
Replies: 5
Views: 922

Re: Rutile, Psuedobrookite from Paramount Canyon, NM

Another specimen. This one is pretty deep in a cavity so a bit harder to shoot.
16852 rutile pseudo copy for pmac.jpg
by bralex
Wed Feb 16, 2022 9:00 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Rutile, Psuedobrookite from Paramount Canyon, NM
Replies: 5
Views: 922

Rutile, Psuedobrookite from Paramount Canyon, NM

Several pics that I've worked on recently - Olympus EM-1 Mk III, Mitutoyo 10x, 1.4x teleconverter, WeMacro rail, Zerene. The teleconverter is the new experiment recently - I have had it for a while, but hadn't been using it with the Mitutoyo lens. It's worked out well as I've been learning to use it...
by bralex
Wed Jan 19, 2022 9:37 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Workflow - New WeMacro Rail
Replies: 16
Views: 6747

Re: Workflow - New WeMacro Rail

Since this got revived, I'll mention the workflow I've settled at, none of which is unique: - I'm controlling the WeMacro rail with an old iPhone - Camera is connected to a monitor for setting up the photos - Shooting RAW on SD cards, which I then transfer to the computer for processing (Olympus Wor...
by bralex
Thu Nov 18, 2021 8:41 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Cassiterite, Hematite, Quartz
Replies: 5
Views: 944

Re: Cassiterite, Hematite, Quartz

That's a beautiful shot! I wouldn't have guessed the small orange crystals were hematite or cassiterite--another example I suppose of how different the macro and micro worlds are. At thumbnail size I'd have guessed vanadinite. Thanks! There's a bunch that, at macro sizes, are completely opaque - th...
by bralex
Wed Nov 17, 2021 10:30 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Cassiterite, Hematite, Quartz
Replies: 5
Views: 944

Cassiterite, Hematite, Quartz

From Paramount Canyon, in Sierra Co. New Mexico - I collected it this past summer. ETA: the font is weird, the FOV is 1.5 mm.
Para Canyon Hem Qz Cass for photomac.jpg