[frank]

The attached sky image is cropped from a post-processed BW image. If you look at it carefully, you will find some periodic structure formed by vertical and horizontal lines, which is absent in the original colour image. Does anybody know the cause for the straight lines?

 

Sometime ago I found this kind of straight lines in an image taken with my GF1 (BW-processed also). I thought it was related to some structure on the image sensor. But now I found this in an image taken with my D700. 

 

I admit that the image was somewhat "over-processed", but I can't imagine it is related to some software algorithm. Does anybody have any idea?

 

Thanks in advance,

Frank

 

 

[Rainer]

... but I can't imagine it is related to some software algorithm.

 

Well, actually I can imagine that the vertical lines that are visible in the upper part of the image

are indeed artefacts of filterfunctions that were applied on the image. But without knowledge of

the type of postprocessing you did  this is like a look into the glas bowl.

 

If it wasn't there in the original (colored) image and it is there after postprocessing ...

odds are, it was caused by postprocessing.

 

Just my 2cts ... Rainer

[frank]

Well, actually I can imagine that the vertical lines that are visible in the upper part of the image

are indeed artefacts of filterfunctions that were applied on the image. But without knowledge of

the type of postprocessing you did  this is like a look into the glas bowl.

 

If it wasn't there in the original (colored) image and it is there after postprocessing ...

odds are, it was caused by postprocessing.

 

Just my 2cts ... Rainer

 

 

Thanks, Rainer.

 

I applied the preset "low key 2" in Silver Efex Pro to the image, then I got the vertical lines. I tried other presets and found that once the brightness of the sky is turned down and the "structure" is turned up to certain amount, the vertical (and horizontal, though not as visible as vertical) lines showed up. 

 

I tried it with ACR 8.3 and did not find those lines. I assume that the "clarity" function in ACR is similar to the "structure" function in the Silver Efex Pro. It seems that CS6 does not have a function of "clarity" or "structure" otherwise I would apply it in CS6 after processing with the Silver Efex.

 

Frank

[Brightcolours]

To me it looks like your Silver Efex Pro works the image in tiles, and the tiles do not exactly connect in a certain step. Which version do you have, and on which platform?

[frank]

To me it looks like your Silver Efex Pro works the image in tiles, and the tiles do not exactly connect in a certain step. Which version do you have, and on which platform?

 

Silver Efex Pro 2.004 on Mac.

[Brightcolours]

Silver Efex Pro 2.004 on Mac.

Ok, I might have 2 on an older Mac (not sure), but if you tell me which PP/effects you used I can try on my Mac with Silver Efex Pro 4 in CS6 to see if it shows similar tiling, or if it is resolved in the newer version.

[frank]

Ok, I might have 2 on an older Mac (not sure), but if you tell me which PP/effects you used I can try on my Mac with Silver Efex Pro 4 in CS6 to see if it shows similar tiling, or if it is resolved in the newer version.

 

 

Open a raw format image file with a grey/blue sky in CS6, in 16bits/chanel. Then open Silver Efex Pro 2, from the presets choose "010 Low Key 2", then I see the lines.

 

I tried 8bits/chanel in CS6, then I did not get the lines in Silver Efex Pro. So, if you use a jpg file as the source, you won't get the lines.

 

By the way, as far as I know the latest version of Silver Efex Pro is 2.

[frank]

It seems that I have found the solution. Turning off GPU in Silver Efex Pro 2, then the problem is gone.

 

I found the solution from the internet. It seems the problem was caused by some incompatibility  between Silver Efex Pro and GPU.