A bug

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

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tevans9129
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Joined: Thu Nov 30, 2017 8:03 am
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A bug

Post by tevans9129 »

The improvement is slow and labored but I am learning, thanks to the expertise of this group.

I am struggling with images that are crisp and not sure if it is the subject, the equipment, my incompetence or perhaps a combination. Please feel free to offer suggestions for improvements and altering the image is acceptable.

D800e, pb6 closed approximately 3.5x, cone, Amscope 4x, 1/200, ISO 100, 300 slices @ 12 microns, Controlmynikon, Stackshot, Zerene.

Image

rjlittlefield
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Post by rjlittlefield »

This looks pretty good except for severe "transparent foreground" artifact on the lower parts of the legs.

See https://zerenesystems.com/cms/stacker/d ... foreground for discussion of that.

For sharpness, it would be helpful to see some non-resized crops showing "actual pixels", as discussed at http://www.photomacrography.net/forum/v ... hp?t=36168 .

What other aspects are bothering you?

--Rik

tevans9129
Posts: 129
Joined: Thu Nov 30, 2017 8:03 am
Location: TN

Post by tevans9129 »

rjlittlefield wrote:This looks pretty good except for severe "transparent foreground" artifact on the lower parts of the legs.

See https://zerenesystems.com/cms/stacker/d ... foreground for discussion of that.

For sharpness, it would be helpful to see some non-resized crops showing "actual pixels", as discussed at http://www.photomacrography.net/forum/v ... hp?t=36168 .

What other aspects are bothering you?

--Rik
Thanks much for the links Rik, I had no idea about the retouching that is explained in the tutorial. Studying that is definitely high on the list.

I cannot explain the "other aspects" it is just like something is not right, like the image is not crisp. I am not even sure that "sharpness" is the issue perhaps it is more like the image is "cloudy" for a lack of a better adjective.

I very much appreciate the comments.

tevans9129
Posts: 129
Joined: Thu Nov 30, 2017 8:03 am
Location: TN

Post by tevans9129 »

Here is the cropped image at 100%. PS is good but it needs something reasonable to work with. But then my PS skills leave a lot to be desired also.

Image

This is the Amscope at approximately 3.5x.

tevans9129
Posts: 129
Joined: Thu Nov 30, 2017 8:03 am
Location: TN

Post by tevans9129 »

This one I think, technically, is somewhat better. Open to all suggestions.

D800e, pb6 closed approximately 3.5x, cone, Amscope 4x, 1/10, ISO 100, 300 slices @ 13 microns, Controlmynikon, Stackshot, Zerene, 2 studio 300ii 1/16 lights.

Image

rjlittlefield
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Post by rjlittlefield »

I agree, this one does look better.

In the previous one, I think a lot of the cloudy appearance is due to the bright blueish background reflecting off the subject.

There may also be some spill into shadow areas through veiling glare. If you have not flocked that cone and possibly the inside of the rear bellows mount, then now would be a good time to do that.

But I notice that areas of the subject that are far away from background look much cleaner than areas that would be directly subject to reflections from the background, so I'm inclined to think that those reflections are more important than overall glare.

Your actual-pixels crop does not look sharp, but a lot of this is likely just diffraction at play. Your objective is what, NA 0.1? So then at 3.5X, you'll be running at about effective f/17. That's plenty small enough to provide diffraction blurring at actual pixels on a D800E.

The only good treatment for diffraction blur is aggressive sharpening, for example with unsharp mask at a size and strength that would reduce a non-diffracted image to junk. See the discussions at http://www.photomacrography.net/forum/v ... hp?t=33724 and http://www.photomacrography.net/forum/v ... 198#203198 .

--Rik

tevans9129
Posts: 129
Joined: Thu Nov 30, 2017 8:03 am
Location: TN

Post by tevans9129 »

rjlittlefield wrote:I agree, this one does look better.

In the previous one, I think a lot of the cloudy appearance is due to the bright blueish background reflecting off the subject.

There may also be some spill into shadow areas through veiling glare. If you have not flocked that cone and possibly the inside of the rear bellows mount, then now would be a good time to do that.

But I notice that areas of the subject that are far away from background look much cleaner than areas that would be directly subject to reflections from the background, so I'm inclined to think that those reflections are more important than overall glare.

Your actual-pixels crop does not look sharp, but a lot of this is likely just diffraction at play. Your objective is what, NA 0.1? So then at 3.5X, you'll be running at about effective f/17. That's plenty small enough to provide diffraction blurring at actual pixels on a D800E.

The only good treatment for diffraction blur is aggressive sharpening, for example with unsharp mask at a size and strength that would reduce a non-diffracted image to junk. See the discussions at http://www.photomacrography.net/forum/v ... hp?t=33724 and http://www.photomacrography.net/forum/v ... 198#203198 .

--Rik
Some good suggestions Rik, thanks. I will definitely look into flocking those areas. My diffusion could probably stand some attention also.

Deanimator
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Post by Deanimator »

Quite nice.

I also have issues with artifacts. I think a lot of it has to do with problems of exposure/lighting/diffusion.

You're definitely on the right track.

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