Lichen on twig - cross sectional view

Images taken in a controlled environment or with a posed subject. All subject types.

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Beatsy
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Lichen on twig - cross sectional view

Post by Beatsy »

Lichen-covered twig sliced through with a razor blade and focus-stacked using various Mitties. Lichen is one of the few subjects that looks more interesting at lower magnifications IMO (at macro scales). Surprised how much it "self shadows" though - blocking light from a very large proportion of its own photosynthetic cells. This is most evident in the 50x image which reveals areas resembling chlorophyll lasagna. All images were shot full frame with a Sony A7 RII and 135mm Sonnar tube lens.

5x Mitty, ~10mm FoV, stack of 222 images with 10µm spacing
Image

10x Mitty, ~5mm FoV, stack of 216 images with 5µm spacing
Image

50x Mitty, ~1mm FoV, stack of 177 images with 1µm spacing
Image

I've found that the jump from 10x to 50x is a bit too extreme in practice. So much so, it "justified" ordering a 20x Mitty after all. I didn't have to twist my own arm very much at all :) On its way...

NicoVB
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Post by NicoVB »

Ordering a 20x mitty, that must have been a tough decision... :D
When you make the most fantastic discovery, a lot of people want a piece of it...

fotoopa
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Re: Lichen on twig - cross sectional view

Post by fotoopa »

Beatsy wrote:I've found that the jump from 10x to 50x is a bit too extreme in practice. So much so, it "justified" ordering a 20x Mitty after all. I didn't have to twist my own arm very much at all :) On its way...
Very interesting posting. I think all weeks why should I buy the 20X or 50X Mit lens. Buying the two lenses will not fit into my budget. Due to the relative smaller difference in the cost price, it was difficult to decide. My preference, however, was the 20X version. That would better fit into my current type of photography.

What strikes me is your step size used. Which is still relatively small so you have to take lots of pictures. Possibly is your step not always perfectly equal so you will choose a finer step. For standard shooting I always use the same values:

Mit 2x: 70 um
Mit 5x: 18 um
Mit 10x: 7 um

If there are to many steps required then it may still works for me with:

Mit 2x: 100 um
Mit 5x: 28 um
Mit 10x: 8 um

My stage is very precise, 1 full step ( 8 micro steps) = 1 um mechanical guaranteed.
For my 75th birthday I can buying best to 20X mit (over 2 years!).
Thanks for posting.

Frans.

Beatsy
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Post by Beatsy »

Frans, you're right - my step sizes are a bit too small. Now I've got automated stacking - the step size is perfectly accurate BUT there is one last source of intermittent vibration that I can't counter. Namely, traffic outside my house hitting a speed bump too fast. This affects maybe one shot in a hundred on average (but random) and causes motion blur (albeit only at pixel level). By overlapping my images a little more than required, I find this helps the stacking "absorb" the odd shaky image and avoids having a nasty artefact in an otherwise perfect stack.

fotoopa
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Post by fotoopa »

Yeah that makes sense.

What I'm lucky, I live in a dead end street with no trafic, get my stack unit on the ground floor. Vibration I do not suffer from.

Lou Jost
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Post by Lou Jost »

Beatsy, I use the same step size as you on my 10x Mitu, for the same reason.

Beatsy
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Location: Malvern, UK

Post by Beatsy »

Lou Jost wrote:Beatsy, I use the same step size as you on my 10x Mitu, for the same reason.
I suspect your vibration source is volcano burps though. Mine's just boring old boy racers trying to wreck their suspensions on the speed bumps :roll:

Lou Jost
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Post by Lou Jost »

When the volcano is active no microphotography is possible at all. Movement of magma deep below the surface causes long periods of vibration, and when the volcano is actually exploding the acoustic shock waves are strong enough to crack my windows (two have cracked so far over the last few years). When it is erupting it also constantly shoots truck-sized rocks several kms into the sky and these land with a thud about 6-7km from my house, shaking the earth and making their own noises....Smaller step sizes don't fix that, sadly. This year has been a calm one, though.

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