Whose eye am I? Take a guess.

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

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Charles Krebs
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Whose eye am I? Take a guess.

Post by Charles Krebs »

OK... I was trying out an objective on my bellows and thought I'd post these two images as a a short (easy) quiz. We've seen the criitter that belongs with the first image very recently, and I think the second one is pretty obvious as well.

These pictures were taken at 40X magnification. A Nikon 40/0.40 CF M Plan SLWD objective was used on the bellows with a Nikon D200. The upper image is made from a stack of 99 photos, the lower from a stack of 48. Helicon Focus was used for both. Because of the high magnification, the focus increment was very small, just 2 microns between each photo. (The scale bar provided below the first image is appropriate for both of them).

Image


Image

LSRasmussen
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Post by LSRasmussen »

Charles,

Wow, I feel the goalposts are moving faster and faster at the moment. Fantastic imagery. My guess would be a Cranefly and an Ant based on
recent posts. I really need to work harder on my lighting. What kind of shutter times are you using here ?

//Lars

acerola
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Post by acerola »

Lars was quicker. My tips are the same. The second one is just amazing.
Péter

Planapo
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Post by Planapo »

Jeez, Charlie! Again pushing the limits!

Now I´ve got cold feet: That 2nd one really knocked my socks off! :wink::D

I am with Lars and Péter regarding the insects photographed.

--Betty

lauriek
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Post by lauriek »

Nice work Charlie! The others have nailed the genus' already I think!

Don't ants have weird textures on their 'skin'!!? (I can see how that 3d structure would make the 'skin' a lot tougher than if it were just a flat 'sheet'...)

Have you ever tried a 100x oil immersion lens on the front of a bellows? :) I don't suppose stacking would be possible with such a setup, but I wonder just where the limit lies - you've already gone beyond where I thought it was!!

rjlittlefield
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Post by rjlittlefield »

Wow!!

Just to let you know, I've been sitting here for several minutes, sipping my coffee and grinning like a madman, just reveling in these glorious images.

Maybe we need a site category for "Goalpost Races" -- let the games continue! :D

--Rik

Charles Krebs
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Post by Charles Krebs »

I knew they'd be easy to spot :wink:. (And thanks for the kind remarks).

The craneflies are out in pretty good numbers around my house, and we've discussed and seen them here recently, so this tiny visual snippet was easy to discern.

The carpenter ant (genus Camponotus) is one where I've always found the eyes interesting when I look at a specimen, but don't think I've ever examined them this closely before. The deep "craquelure" like texture to the head itself was something I had not really noticed before. When you look at these ants "overall", the head seems a dull black, but the fine texture is too small to really see in detail.

Lars...
Wow, I feel the goalposts are moving faster and faster at the moment... ....I really need to work harder on my lighting. What kind of shutter times are you using here ?
We do seem to have hit a "critical mass" with this technique here in the group. Yes... you just can't overstate the need to pay close attention to the lighting. When you look at some of the superb images folks have been posting recently you can really see how good lighting can take an image to an entirely different "level". When making these images, after all the preparation required, there is a tendency (at least for me) to want to "get going" and start taking the images. Often I need to slow myself down and force myself to spend more time fine-tuning the lighting. (Even then, when all the work is done I can usually find something I might do a little differently if I were to start over again).

The ant image was taken using electronic flash (very subdued room light, 1 second exposure with flash sync at the end). For the cranefly I went to tungsten light. I used a much "heavier" diffusion than with the ant, and wound up with an 8 second exposure per image. Longer than I really like to use, but there did not seem to be a digital noise issue. (I can see where I will need a less "dense" dome type diffuser when working at these magnifications).

augusthouse
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Post by augusthouse »

Rik wrote:
Just to let you know, I've been sitting here for several minutes, sipping my coffee and grinning like a madman, just reveling in these glorious images.
I can just imagine that! :smt112

Charlie,
The SLWD - does that mean 'Seriously Long Working Distance'?

I'm trying to work out how you were able to make the light dance between the subject and the objective.

Craig
To use a classic quote from 'Antz' - "I almost know exactly what I'm doing!"

Charles Krebs
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Post by Charles Krebs »

Craig,

SLWD = "super long working distance" in Nikon-speak.

For this 40/0.40 (5.1mm focal length) that means a working distance of 14.9mm... quite remarkable really. The "regular" 40/0.65 has a working distance of 1mm, and the LWD 40/0.55 has a working distance of 3mm. You do lose some numerical aperture -- and thus potential resolution -- but I'll take that in order to be able to "light" my subjects a little more effectively. Besides, even with a NA of 0.40, the DOF (lack of it, really! :( ) makes things challenging. There are quite a few subjects I would only tackle if I were in a masochistic mood!

rjlittlefield
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Post by rjlittlefield »

Charlie, can you speak to the resolution on subject of the SLWD 40/0.40 versus say the ELWD 20/0.40 that you've used for other work?

From a theoretical standpoint, both lenses should have the same resolution on subject, with the 40X simply providing a 2X enlargement of the central half of the 20X's field. When used with a sensor having sufficiently small pixels, one can (in theory) get the same image from both lenses by cropping the 20X.

But theory and practice are often different.

How does the practice work out? Aside from the reduced noise and pixelation that go along with using the full sensor instead of a quarter of it, what improvements in image quality do you see from the 40X lens?

--Rik

Charles Krebs
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Post by Charles Krebs »

Rik,
A good question. One I don't have a good answer for... yet.

=; Caution... the following reply contains ramblings and thoughts that will be incredibly dull and boring to most sane people who just want to take and see pictures... but I sometimes find it "fun" to ponder, and then see, how the "theory" matches up to the "reality" :smt017

Now let's see, who's still here?... oh... OK Rik, here we go... :wink:

We're definitely into the place where it's possible to start looking at the situation in a similar manner to what might be done with the microscope. I know, that you know, the "numbers". According to those numbers, with my D200 I am putting 2.75 pixels on the smallest resolvable detail with the 20/0.40, and 5.5 pixels on the smallest resolvable detail when using the 40/0.40. So there should be plenty of "empty magnification" with the 40X and you would expect very close final results (at least as far as resolution of detail is concerned) if you simply took the corresponding section out of the 20X image. But then, as you suggested, you have to throw in some things that are tough to quantify... noise, pixelation, and some "wild card" Bayer pattern issues like the resolution of certain colors and patterns. Frankly, so far I haven't done enough comparison shots with these 2 lenses on bellows to give you a direct solid answer.

Things are not entirely comparable to the compound microscope, but I have done many direct comparisons there, and my initial impressions regarding your question seem similar to what I find with my scope. The condenser I use the most is limited to a NA of about 0.9. So whether I use my 40/0.95, 60/1.40, or 100/1.40 I really shouldn't expect a tremendous difference if I were to pull out the corresponding image area on the sensor for each objective. Together with the relay optics used, my camera sensor is easily up to recording the image detail from the 40X with 4.8 pixels per resolvable detail... far more than should be needed. With the 60X and 100X I should be recording images that show even greater amounts of "empty magnification". With the 100X I am putting about 9 pixels on each resolvable detail. The full frame images with the 40X look unquestionably more detailed and "better" in every photographic sense. But if I try to "blow up" a portion of that image made with the 40X so that it matches the frame captured by the 100X (or 60x for that matter) I will generally prefer the image made with the higher mag objective. The difference is not really that great, nothing near what many would assume if they just quickly looked at the "lens" magnifications -- a 40X versus 100X . But if you want to see something at the magnification provided by the more powerful objective, the difference seems worth it to me.

With the M Plan 20X and 40X used on a bellows, there would be less "sampling overkill", so I might reasonably expect to see a slightly greater difference than with my microscope comparisons. It still might not be very significant for some... perhaps too far up the "diminishing returns" path. It's something I need to explore more by looking at some carefully shot comparisons. It is, after all, the resulting image that matters.

LSRasmussen
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Post by LSRasmussen »

Charles,

Many thanks for your answer regarding the shutter times. 8 seconds/image and 99 images ! Something to think about. I've never used more than half a second/image. I've finally borrowed a fiber light unit so hopefully this will help with my image quality.

//Lars

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