Amber with Fly

[Manfred M]

I shot this piece of amber jewelry that contains a fly by sitting it on a piece glass with a piece of Japanese Washi paper between the glass and amber. I back-lit the shot. I brought out some of the details in post. I think it is still missing something; perhaps a shadow? It's assembled from 6 shots using Zerene stacker.

[Wavelength]

i think it lacks some impact.... That rarely happens in the case of your images....

[Antonio Correia]

Perhaps with a black background...

[Rufus]

A couple of thoughts:

1. The amber does not appear to have any depth, and appears to be a slender disc. If we are viewing the flat face of a cut piece of amber, then it would be nice to see a hint of that by way introducung some shadow or distance from the background.

2. I like the crop/framing but there is a lot of background. Might a mottled background be less stark perhaps than plain white (or plain black)?

[Round Tuit]

+1 to David`s comments. It also looks like you have some stacking halos around some of the arched structure. Dan would be able to confirm whether they are or not.

[DanK]

+1 to David`s comments. It also looks like you have some stacking halos around some of the arched structure. Dan would be able to confirm whether they are or not.

Hard to tell at this resolution whether there are stacking halos, but there are a few things that look like they might be. In particular, look at the fuzzy brown area tracking the specular highlights at the top of the head (marked in red below).



If there is a fairly large distance between the head and the surface beyind it, that could cause a halo.

If this was stacked with DMap, PMax might do better in terms of halos. One can retouch also retouch from either a composite or a single image. I often use a DMAP composite as my base (because it does a bit better with colors) and then reduce or eliminate halos by retouching from a PMax composite. However, in the end, one sometimes has to do manual cloning to get rid of some of it.

[Manfred M]

Thanks Dan - it was done with Dmap. I tried Pmax and it showed no real advantage over Dmap as I could not adjust the contrast threshold above "0" without getting lots of artifacts.

I suspect the halos are likely due to the shape of the work as well as wrap from the back lighting. Here is a SOOC image of one of the layers and one can see some halos.




The issue is shooting a highly polished, reflective metal (i.e. gold). Light is bouncing off the various 3D surfaces.

[Rufus]

...Here is a SOOC image of one of the layers ...

I see a mottled background in a pleasing colour in this image so perhaps this could be imported into the processed image. Having said that, I am sure Manfred had good reason to remove it.

[DanK]

Manfred,

The artifact I circled is not in the SOOC image, which makes it quite likely that it is a stacking issue.

As I understand it, the issue is parallax. The software has to adjust for differences in magnification as it works through the stack. If there is too large a gap, that is, if the front-to-back distance is too large, it can't manage it. There difference in parallax between the last image with the front edge in focus and the first image with the background in focus is too large. I don't know the math underlying the two methods, but DMax is markedly inferior in terms of halos.

I don't understand your comment about PMax. There is a contrast adjustment for DMap, but I was not aware of one for PMax.

[Manfred M]

Sorry - typo on my part, I meant DMap, not PMax.

This is the partially processed DMap output, using the same input files. It was not as sharp as the PMax processed version, so I went further with the DMap image.

I understand the physics of what is happening to create the halos. With focus breathing of the lens that close to the subject the two images are not identical in size, so the stacking software makes certain assumptions as it blends the two images. The interpolation algorithms are likely responsible for this effect and it can be taken out with a bit of care in post.

[DanK]

In general, PMax is supposed to be better at preserving fine details, which fits with your experience. I haven't usually found a practical difference.

I'd have to disagree with your "a bit of care in post". Sometimes that is true, but with complex images, it can take a lot of time and can be very hard to do well. It depends on the number of halos and what is around them. The most difficult I have done in the last few years is the one I'll post below. If you look closely, you'll see a number of remaining artifacts and errors in my touching up.

Sorry - typo on my part, I meant DMap, not PMax.

This is the partially processed DMap output, using the same input files. It was not as sharp as the PMax processed version, so I went further with the DMap image.

I understand the physics of what is happening to create the halos. With focus breathing of the lens that close to the subject the two images are not identical in size, so the stacking software makes certain assumptions as it blends the two images. The interpolation algorithms are likely responsible for this effect and it can be taken out with a bit of care in post.

[bje07]

in image #1 the stone seems flat and only the stone, the first wing and the leg seem in focus