Search found 108 matches

by physicsmajor
Thu Feb 01, 2024 10:49 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Kinoite on Apophyllite from the Christmas Mine
Replies: 5
Views: 483

Kinoite on Apophyllite from the Christmas Mine

After a long absence (moved house, upgraded equipment, new automatic stacking rig) I have some new minerals to share! This is a micro mount specimen from the well-known Christmas Mine in Gila, Arizona of Kinoite (blue tabular crystals) on colorless Apophyllite. This is the type locality for Kinoite....
by physicsmajor
Tue Nov 14, 2023 1:22 pm
Forum: Equipment Discussions
Topic: LED lamps from Ebay UK
Replies: 6
Views: 2496

Re: LED lamps from Ebay UK

Anyone see an offering with slightly less output but claimed >90 CRI?

I might buy and disassemble one of these and see if the LED module might be standard enough to be exchanged.
by physicsmajor
Tue Nov 14, 2023 1:17 pm
Forum: Equipment Discussions
Topic: Can You repurpose a 3D printer for focus stacking?
Replies: 12
Views: 3980

Re: Can You repurpose a 3D printer for focus stacking?

If anyone wants the combination Arduino and Raspberry Pi code I wrote to control that rail, including closed loop control with input from the high resolution quadrature linear encoder, I can give you access (honestly I should just clean it up and open source it). It does currently use a Polulu Tic s...
by physicsmajor
Sat Jun 24, 2023 7:28 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: how to retouch stereo images
Replies: 32
Views: 2059

Re: how to retouch stereo images

I have just now rewritten the Retouching section of https://zerenesystems.com/cms/stacker/docs/syntheticstereo to read as follows: Retouching In most cases you cannot retouch shifted outputs from un shifted inputs because image features will not line up correctly. So, the key trick for retouching s...
by physicsmajor
Sat Jun 24, 2023 7:20 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: By request, my setup
Replies: 4
Views: 2912

Re: By request, my setup

Which make/model led lights do you use? The setup looks very detailed. From the first image, the square lights appear to be Godox LED64 units. Claimed 1000+ Lux at 0.5 meters is quite good for the size; the bicolor temp adjustment range is limited to the cooler side of the spectrum though (5500k - ...
by physicsmajor
Fri Apr 28, 2023 8:22 am
Forum: Equipment Discussions
Topic: Nikon Small World eligible lenses
Replies: 10
Views: 1938

Re: Nikon Small World eligible lenses

I work a lot with my Minolta 5400 lens, but objectively I think that its use cannot be considered to participate in the Nikon Small World contest The rules say that the images must be taken by the participant using an optical microscope, therefore the mandatory use of a microscope lens, even if it ...
by physicsmajor
Sun Apr 23, 2023 1:25 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: NMM-3529
Replies: 2
Views: 914

Re: NMM-3529

This is fascinating and I'd love to know more about how such tiny specimens would be found and identified, given their size. Melt ice and sort through the powder attracted by an electromagnet under a stereozoom? Sheer luck?
by physicsmajor
Fri Dec 02, 2022 8:54 pm
Forum: Equipment Discussions
Topic: Manual stepper
Replies: 6
Views: 1119

Re: Manual stepper

from all I've read and from some basic test of myself, microsteps will only get you so far with accuracy. In what I've seen most setups will suffer from non-uniform step size once we go into higher micro stepping. I also doubt that the ebay linked rail will truly get 1um accuracy. The stage I linke...
by physicsmajor
Fri Dec 02, 2022 10:48 am
Forum: Equipment Discussions
Topic: Manual stepper
Replies: 6
Views: 1119

Re: Manual stepper

Allan has done a lot of great work, but the project you're looking at is likely not fully generalizable to LEGO. K'NEX is probably not even worth considering. LEGO has incredible tolerances, claims vary but what I read is somewhere around 2 microns. The problem is that tolerances stack in a mechanic...
by physicsmajor
Tue Sep 06, 2022 9:51 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Shutter speed vs magnification
Replies: 12
Views: 1838

Re: Shutter speed vs magnification

If you're seeing blur at higher magnifications, it's more a commentary on your imaging system or environment than any real limitation inherent to shutter speed. A perfectly rigid system in a room without drafts and a stationary subject - or one with an electronic shutter - should have performance en...
by physicsmajor
Tue May 31, 2022 1:29 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Questions about UV fluorescent photography
Replies: 18
Views: 2890

Re: Questions about UV fluorescent photography

No filtering was applied on the light source or camera side, and along the top/right you can see the natural deep green of this Rogerly fluorite. There is essentially no violet pollution; the brilliant blue is accurate for this particular specimen. What settings do you use for nominal white balance...
by physicsmajor
Tue May 31, 2022 12:46 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Questions about UV fluorescent photography
Replies: 18
Views: 2890

Re: Questions about UV fluorescent photography

Rogerly_Fluorescent.jpg This is a macroscopic focus stack from a 14.8 cm wide specimen of fluorite from the Rogerly mine in England, lit from the left and slightly below with my Convoy with a Nichia U365 emitter, mixed with dim natural light from above. The Convoy was about 1.5 meters from the spec...
by physicsmajor
Tue May 31, 2022 9:30 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Questions about UV fluorescent photography
Replies: 18
Views: 2890

Re: Questions about UV fluorescent photography

Putting short pass filters at the UV flashlight will improve a lot your results. Best ones are expensive but if the size matches Chinese ZWB2 are very affordable and convenient. Emission long pass filters for the camera/eye side are also recommendable (for the eyes wear protective glasses, any eyeg...
by physicsmajor
Thu May 26, 2022 8:33 am
Forum: Equipment Discussions
Topic: 3D Printing M25 Threads for Objective Cases
Replies: 13
Views: 1792

Re: 3D Printing M25 Threads for Objective Cases

If you want translucent, you want a bit of deliberate overextrusion and 100% infill (actually ideally 999 walls with 0% infill and gap fill enabled). Any gaps - infill or between layers - will be obvious and visible. However this has to be balanced with the need for the threads to work at the top of...
by physicsmajor
Sat May 21, 2022 9:34 am
Forum: Equipment Discussions
Topic: 3D Printing M25 Threads for Objective Cases
Replies: 13
Views: 1792

Re: 3D Printing M25 Threads for Objective Cases

If you would like someone to test, I have multiple very highly tuned enclosed printers and can print in PLA as well as ABS, ASA, and Polycarbonate. Throw some STLs my way. My initial suggestion for such fine threads is that it should be possible to print but will require a well tuned printer and def...