Search found 249 matches

by JW
Tue Feb 27, 2024 6:30 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: some scales
Replies: 120
Views: 5862

Re: some scales

I haven't been able to see cross-eyed, stereo, or otherwise, 3D images. Have you already tried the parallel view? I can't squint either and can't see stereo in pictures with crossed eyes. But I create them so that I set up the parallel view first, and then, when everything is ready, I simply swap t...
by JW
Sat Feb 24, 2024 9:06 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: some scales
Replies: 120
Views: 5862

Re: some scales

ADi - neat trick with the animated GIF image - which is very useful for those of us with low vision in one eye, I haven't been able to see cross-eyed, stereo, or otherwise, 3D images. Really makes the structure come alive. Too bad about the transparency though, but I imagine its too hard to fix.
by JW
Mon Jan 22, 2024 5:56 pm
Forum: Equipment Discussions
Topic: AstrHori 25mm f/2.8 2x-5x full-frame macro lens
Replies: 52
Views: 1737

Re: AstrHori 25mm f/2.8 2x-5x full-frame macro lens

I saw this over at PetaPixel also, and then went to AstrHori's website. A close examination of the provided video shows that the image made with the AstrHori lens is significantly lower in contrast as compared to the Laowa. I didn't notice any CA or other image defects. Since the imaging conditions ...
by JW
Wed Nov 22, 2023 11:59 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Saponite
Replies: 3
Views: 2672

Re: Saponite

Bob - saponite and similar are phyllosilicates, so typically form platy or sheet-like crystals. I suspect that there is more going on here, in that there are tiny needle-like crystals, maybe natrolite, that the saponite is decorating. Jay - I am not familiar with the geology of the region, but in a ...
by JW
Sun Nov 12, 2023 7:32 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Some minerals from Paramount Canyon, New Mexico
Replies: 14
Views: 3408

Re: Some minerals from Paramount Canyon, New Mexico

Jay - check your PM's. And thanks for commenting on the loading times.
by JW
Sun Nov 12, 2023 7:31 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Some minerals from Paramount Canyon, New Mexico
Replies: 14
Views: 3408

Re: Some minerals from Paramount Canyon, New Mexico

Still missing the Fov :) Pierre - thanks for noticing the oversite, I don't have FOV information as I am no longer certain which lenses were used or how much PS cropping, if any, was performed. I do have the size of the crystals, now noted. Usually when photographing crystals like this, I try to fi...
by JW
Sun Nov 12, 2023 7:30 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Some minerals from Paramount Canyon, New Mexico
Replies: 14
Views: 3408

Re: Some minerals from Paramount Canyon, New Mexico

colohank wrote:
Sat Nov 11, 2023 2:59 pm
Looks like a double-terminated quartz crystal in that last Bixbyite photo.
Yes, lots of quartz as one of the accessory minerals in these vuggy rhyolite rock samples.
by JW
Sat Nov 11, 2023 12:33 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Some minerals from Paramount Canyon, New Mexico
Replies: 14
Views: 3408

Re: Some minerals from Paramount Canyon, New Mexico

OK, so much for third party hosting - I've replaced the images with PS reduced sized versions and uploaded.

Here is another bixbyite-(Mn) with interesting trisoctahedral crystal morphology, 0.5 mm crystal:
7.jpg
by JW
Fri Nov 10, 2023 10:20 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Some minerals from Paramount Canyon, New Mexico
Replies: 14
Views: 3408

Re: Some minerals from Paramount Canyon, New Mexico

That is good feedback, I was hoping to save a processing step, will reduce size and repost once I am at my PC.
by JW
Thu Nov 09, 2023 7:20 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Some minerals from Paramount Canyon, New Mexico
Replies: 14
Views: 3408

Re: Some minerals from Paramount Canyon, New Mexico

Is there a way to add a tag to the <img> tag to change the image width?
by JW
Thu Nov 09, 2023 7:07 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Some minerals from Paramount Canyon, New Mexico
Replies: 14
Views: 3408

Some minerals from Paramount Canyon, New Mexico

These were taken with either the Canon MP20mm on extension tubes or Canon MPE-65, flash, Canon 50D body, ZS, with a bit of PS for color balance Ilmenite - 0.9 mm crystal: 1.jpg Bixbyite-(Mn) -1.0 mm crystal: 2.jpg Bixbyite-(Mn) - 1.4 mm crystals: 3.jpg Pseudobrookite - 1.6 mm crystals: 4.jpg Hematit...
by JW
Tue Oct 31, 2023 7:02 pm
Forum: Photography Through the Microscope
Topic: Brachinite meteorite thin section, cross polarised light
Replies: 4
Views: 1689

Re: Brachinite meteorite thin section, cross polarised light

Brachina is an olivine rich meteorite indeed dated about 4.6 billion years ago. More details here : https://www.mindat.org/loc-261421.html
by JW
Tue Oct 31, 2023 7:00 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Saponite
Replies: 3
Views: 2672

Saponite

Saponite is usually found as clay-rock masses. This is about as good as it gets for this mineral. Taken with my (new to me) Canon FD 20mm macro, f/5.6, with 50 mm extension plus FD/EOS adapter, on my venerable Canon EOS-50D. ZS DMap, essentially no other corrections other than resizing and cropping....
by JW
Fri Oct 20, 2023 4:05 pm
Forum: Equipment Discussions
Topic: Printing Nikkor
Replies: 32
Views: 4718

Re: Printing Nikkor

Thanks for all of the comments, appreciated. Looks like these lenses will be winners at +/- 50% of their rated magnification. Do I need yet another lens in the 0.7 to 1.4x range? No, but... (enter OCD comment here).
by JW
Thu Oct 19, 2023 2:53 pm
Forum: Equipment Discussions
Topic: Printing Nikkor
Replies: 32
Views: 4718

Printing Nikkor

OK, all of this ongoing discussions on Printing Nikkor lenses has got my interest peaked, to say the least. Not being familiar with the lens, other than its designed to be used at about 1:1, what is the useful magnification range for a camera with a full size sensor? I am assuming simple extension t...