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by rjlittlefield
Mon Apr 15, 2024 10:50 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: For you micro-mineral photography people, how do you deal with holding minuscule, fragile specimens?
Replies: 4
Views: 83

Re: For you micro-mineral photography people, how do you deal with holding minuscule, fragile specimens?

and uhhhh, I might have to necromance your old thread on the cystidia sub-linked in your fiber/springtail thread! (unless that's a huge no-no) Resurrecting old threads is OK as long as the new posting adds information or asks a relevant question, and does not look like it's being done with intent t...
by rjlittlefield
Mon Apr 15, 2024 8:47 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: For you micro-mineral photography people, how do you deal with holding minuscule, fragile specimens?
Replies: 4
Views: 83

Re: For you micro-mineral photography people, how do you deal with holding minuscule, fragile specimens?

It's a bit fiddly, but supporting the specimen on a bed of fibers can give some extra freedom for stable positioning. For an ancient example, see https://www.photomacrography.net/forum/viewtopic.php?p=2796#p2796 (and the surrounding thread). Edited to add: the stereo view at https://www.photomacrogr...
by rjlittlefield
Thu Apr 11, 2024 5:56 pm
Forum: Equipment Discussions
Topic: Panasonic 45-175 mm as tube lens / focus bracketing
Replies: 20
Views: 422

Re: Panasonic 45-175 mm as tube lens / focus bracketing

I have noticed a recent change in behavior of notifications from the forum. Nowadays I do not get a notification of new replies to a post I have responded to. Maybe some flag got cleared by me accidentally?? It's also possible that some conflict has developed between the email servers used by you a...
by rjlittlefield
Thu Apr 11, 2024 1:26 pm
Forum: Equipment Discussions
Topic: Panasonic 45-175 mm as tube lens / focus bracketing
Replies: 20
Views: 422

Re: Panasonic 45-175 mm as tube lens / focus bracketing

Björn, Regarding your PM, see FAQ: There's a PM stuck in my Outbox. What's wrong? Most likely Lou is just away from his computer for a while and will see your message when he gets back. As for focus bracketing, I have no experience with that exact lens but perhaps some general info will help. A good...
by rjlittlefield
Thu Apr 11, 2024 11:40 am
Forum: Equipment Discussions
Topic: No sharpness when using mitutoyo 10x (also halo, low contrast)
Replies: 16
Views: 634

Re: No sharpness when using mitutoyo 10x (also halo, low contrast)

I think i solve the problem witch was the light control from the back. It seems that the HR is much more sensitivie for it. I spend couple days to have more controled light and below are results ... 10:1 HR by Radoslaw DIY , on Flickr Thanks for the update. I downloaded the maximum resolution image...
by rjlittlefield
Thu Apr 11, 2024 10:35 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: rotating worms
Replies: 4
Views: 412

Re: rotating worms

Well the stationary pixels or dust particles are always in the same spot so naturally they will produce an artificial "line" in space during stacking. With a rocking stereo the application basically assumes this "line" exists and will animate it like the rest. Just so, and well said! Also important...
by rjlittlefield
Thu Apr 11, 2024 10:29 am
Forum: Nature Photography -- Macro and Close-up
Topic: closeup photo of solar eclipse in Richland, WA
Replies: 0
Views: 97

closeup photo of solar eclipse in Richland, WA

PXL_20240408_185833738_crop.jpg Here in Washington State the solar eclipse was only partial, max coverage about 37%. I don't have any equipment suitable for pointing at the sun, but I do have some window shades with little holes that make pretty good pinhole cameras. Most of the time they just show...
by rjlittlefield
Wed Apr 10, 2024 1:31 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Methods to evaluate performance of a focus rail
Replies: 10
Views: 845

Re: Methods to evaluate performance of a focus rail

Wich is yours? It is labeled only "aus JENA", but somehow I figured out that it's a Laboval 2. As of today, Google Image search for aus jena laboval 2 shows many images that look right. Oddly, the #2 hit is from my own website, where long ago I posted some notes about rehabbing the focus block. See...
by rjlittlefield
Wed Apr 10, 2024 9:24 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Methods to evaluate performance of a focus rail
Replies: 10
Views: 845

Re: Methods to evaluate performance of a focus rail

The total displacement of 120mm (not 140mm as I wrote) that the rail travels is equivalent to six and a half turns of the buttons, which when divided gives 18.46. Isn't there anything missing here? I don't think that you (or Pau :wink:) have missed anything very important. But adding some details.....
by rjlittlefield
Tue Apr 09, 2024 6:35 pm
Forum: Nature Photography -- Macro and Close-up
Topic: Neottia cordata (Heartleaf twayblade orchid)
Replies: 15
Views: 227

Re: Neottia cordata (Heartleaf twayblade orchid)

Really nice set!

That scale shot at the end adds hugely to my pleasure in going back to study the closeup portrait.

--Rik
by rjlittlefield
Tue Apr 09, 2024 3:37 pm
Forum: Equipment Discussions
Topic: Zerene - Question
Replies: 3
Views: 159

Re: Zerene - Question

The above explanation is correct as far as it goes, but there may be another complicating factor. Sometimes the alignment process can be led astray by asymmetry in how the subject appears to change shape and size as it goes in and out of focus, with the result that the alignment process introduces "...
by rjlittlefield
Sun Apr 07, 2024 10:19 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: cross-sections of MLCCs (multi-layer ceramic capacitors)
Replies: 8
Views: 242

Re: cross-sections of MLCCs (multi-layer ceramic capacitors)

the depth on the stereo photo is quite large Well, it's easily seen. But in terms of Zerene Stacker's controlling value, stereo shift for the above image is only plus and minus 3.6%, barely larger than the default value of plus and minus 3.0%. If I had not told you that the shift percentage corresp...
by rjlittlefield
Sat Apr 06, 2024 4:49 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: cross-sections of MLCCs (multi-layer ceramic capacitors)
Replies: 8
Views: 242

Re: cross-sections of MLCCs (multi-layer ceramic capacitors)

I'm glad you found it interesting. I certainly was not expecting that last step of strange structure with the 10 pF size. My brain is now toying with the idea of some sort of automated sand-and-shoot setup that could make a time-lapse of sectioning its way through the whole structure. Probably that'...
by rjlittlefield
Fri Apr 05, 2024 5:20 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: cross-sections of MLCCs (multi-layer ceramic capacitors)
Replies: 8
Views: 242

cross-sections of MLCCs (multi-layer ceramic capacitors)

Just to set the stage, here's what we're talking about. https://janrik.net/MiscSubj/2024/MultiLayerCeramicCapacitors_20240404/IMG_4336.jpg These are small ceramic capacitors that sell for about $0.025 each in retail boxes at Amazon. Across a couple of kits, they range in rating from 10 picofarads up...
by rjlittlefield
Fri Apr 05, 2024 3:05 pm
Forum: Equipment Discussions
Topic: Any good 15x objectives?
Replies: 8
Views: 358

Re: Any good 15x objectives?

And I wouldn’t want to push 20x down to 15x with a 150mm tube lens because I’m fairly certain edge performance would be terrible on FF. For what it's worth, my Mitutoyo M Plan Apo 20X NA 0.42 pushes down to 10X on APSC and the corners hold up OK. I searched the forum to see if anybody else had post...