I was taking some stacks of a fairly nondescript sample of malachite, when...

Here is the final stack, with the offending frames removed, luckily I was using small enough steps to avoid focus banding.

I love cacoxenites! You know we have some really great examples here in Spain. I’m obsessed with that fourth photo… and the way you handled the highlights is just amazing. Thanks Soldevilla. You probably agree that cacoxenite is one of the most photogenic microminerals, especially the Spanish examp...

... Laowa 2.5-5.0x lens, at 5x f/5.6, 200mm extension... Adding 200mm extension tubes to 25mm lens which is already set for 5x? How much magnification this gives you? This setup should be deep in the diffraction territory although these picture are not particularly soft and mushy... maybe because t...

All samples are from the Moores Mill phosphate locality near Mt. Holly Springs, Cumberland County, Pennsylvania, USA. All are crops/size reductions from Laowa 2.5-5.0x lens, at 5x f/5.6, 200mm extension on Canon 5DSr, ZS PMax, hot light illumination with a pair of double diffused Litemons LC30D's. 2...

Red beraunite and yellow cacoxenite, from Moores Mill phosphate deposit, near Mt. Holly Springs, Pennsylvania. Canon 5DSr with Laowa 2.5-5x at 2.5, f/5.8, about 200mm extension tubes, a pair of double diffused Litemons LC30D's. ZS Pmax

Long prismatic hexagonal crystals - likely apatite, if there is phosphorous present, not something you want to be breathing. Very nice images, btw.

Rik - always nice to be validated. As an engineer I am used to employing brute-force methods to solve problems, and once something works, stick with it. If I was making 1000's of stacks each requiring 100's of images, which I know some on this forum do, then being more informed would be important. I...

I've been half-heartedly reading this thread, as I am only a mere chemical engineer and not an optical or electrical engineer. :roll: For me, I just pick a step size and start stacking, step size is based on experience of using a certain lens, f-stop, and sensor size, and using the rule that each im...

Darionett - you may want to find the following - disclosure - I have not, however, Pavel Kartashov is well known in both the mineral and corroded coin communities. MINERALIZATION CRUSTS AND OTHER NEOGENIC FORMATIONS AT CAST COINS OF CHINESE TYPE, Part1 P.M.Kartashov, Belov'sLaboratory of Minerals Cr...

I find that strategically placing arrows often helps to point the way to the subject.

Rik - UV-A wavelengths are well known to activate catalysts for oxidation - converting pollutants such as nitrous oxide, ammonia, carbon monoxide, in the presence of air, into harmless nitrogen, water and carbon dioxide. High intensity is needed to meet the air flow and throughput requirements for i...

Cooling becomes important when you cram 1-2 kW of LED UV-A emissivity power into a small space, like we were foolish enough to try. Hint: larger power supplies and appropriate gauge wiring are your friends here.

I bought this inexpensive self-adhesive tape for framing my 140" diagonal projection wall/screen. I was surprised about how black and non-reflective it is, even when illuminated by a bright home-theater projector, and so its probably suitable for many flocking and similar uses. As usual, there are a...

Not sure if this helps, Way-to-cool offers a wide range of UV light sources, plus they will custom build as needed : https://www.fluorescents.com/ I should also add the we (at work) have built our own UV-A lamps out of commercially available LEDs supplied by Luminus Devices, which can be obtained fr...

Strictly speaking, no longer wulfenite, but a pseudomorph - most likely smithsonite replacing wulfenite crystals. The darker green to the right is botryoidal pyromorphite.