Ricoh GR and seemingly compression artefacts in the sky

[silent1]

I'm having a lot of fun with my newly acquired Ricoh GR.
But I noticed a weird and somehow annoying effect in the "gradient" areas of my long-exposure pictures.
A couple of examples will clarify my problem:

(look at the sky)

(look at the portion of the sea on the bottom half part of the photo)

At first I thought of some kind of jpeg compression artefact due to the export mechanism of LR but I can still see it zooming 100% into the original image. It seems to be present even in the raw file.

I noticed the same problem in some night pictures taken by diglloyd here: http://diglloyd.com/blog/2013/20130620_2-Ricoh-GR-night-shooting.html

Sky is perfectly ok in "normal" pictures (e.g. the kind of picture you would handhold your camera).
Is something wrong in the way the GR processes long exposures pictures?

 

[taemo]

does this happen only when doing long exposure and low light photography?
is noise reduction turned on?

 

[kbg32]

Were these orginally RAW files, or are you posting the OOC jpegs? Oops. My bad. I know that it is impossible to turn off the noise reduction on the GR. It could be affecting your long exposures. I would go into the menu and set the NR for the lowest possible setting. As well, it could be the result of your RAW processing.

BTW, I can barely see it on my monitor at work.

 

[silent1]

Yes, it looks like a problem of a combination of long exposures and low light environment.
I haven't touched the noise reduction settings. The ISO set for those two pictures should be 100, because I was aiming at long exposure times. Not sure if the noise reduction algorithms kicks in at ISO 100 already.

 

[silent1]

Were these orginally RAW files, or are you posting the OOC jpegs?

These are OOC jpges, although the raw files as handled by Lightroom 4 do seem to show the same problem.

 

[kbg32]

The NR in the GR as to my knowledge, I own one, can't be completely turned off. It will even affect ISO 100 images, especially OOC jpegs, but leaves the RAW untouched.

 

[silent1]

The NR in the GR as to my knowledge, I own one, can't be completely turned off. It will even affect ISO 100 images, especially OOC jpegs, but leaves the RAW untouched.

I will have a closer look at those RAW files and my camera settings for what concerns the noise reduction.

EDIT: noise reduction is off for ISO 100 pictures, and so is the Slow Shutter Speed NR setting. I need to have a closer look at those RAW files now.

 

[kbg32]

Let me know what you find. I know that the "gradient" effect, can be happening in post processing.

I haven't gotten this with mine, though I haven't done any long exposures. One problem I was getting, was color bleeding in the RAW files at high ISOs. I have been able to control that in post processing in CS6.

 

[stompyq]

How can NR effect RAW files? I thought by definition they are straight out of camera minus any processing?

 

[zuikologist]

Perhaps there is some residual in-camera processing going on even in RAW files?

How can NR effect RAW files? I thought by definition they are straight out of camera minus any processing?

 

[kbg32]

Are you using the camera's in-processing of RAW files? This certainly would apply NR to the RAW.

 

[David_Manning]

I noticed that on my GR this week. I sent this RAW file through SilverEfex Pro 2 and added grain, which usually looks very uniform. On this and a few other GR shots, it looks way different...(look at the sky)

 

[kbg32]

Can you post what camera settings you were using David?

 

[kennylovrin]

It looks like typical jpeg compression artifacts to my eye because it's not "smooth" lines in the banding, looks like jpeg trying to compress away very similar color values.. But then again you would most likely not see it when viewing the raw file in lightroom i suspect.

smooth gradients like this is tricky though, there just aren't always enough bit depth to cover really really smooth gradients, i've had it happen when i had my 5dmkii as well. it's not uncommon for designers to add noise to smooth gradients for more or less the same reason.

but then there is the other aspect of banding which can also be caused by the screen not being able to display it correctly (that's most likely not what we're looking at here though)

 

[kbg32]

You might be onto something Kenny. I wonder if it is the colorspace the camera is shooting in vs. the colorspace that the editing software is opening the files in. This can be changed via camera/computer.

 

[BLKRCAT]

correct me if Im wrong, but from my understanding, colorspace will just effect the gamma of the image. That's what it is, it's the definition of the gamma curve applied to an image so that it looks "correct" when viewed on a monitor since monitors do not display linear.

It won't have any effect on artifacts or whatnot.

 

[silent1]

I had a second look at the RAW file and indeed it seems unaffected by the compression artifacts, this is a 100% crop of the first image:

Compare to the jpeg OOC:

Trying to export the RAW file into a jpg file in LR, even at 100% quality doesn't solve the problem, as the resulting jpg image shows similar compression effects.

 

[kennylovrin]

try exporting it as a tiff or png, if it doesn't show the problem then at least you know it is definitely the jpeg compression.

i'm pretty sure i had exactly the same problem with a few photos myself, it was impossible to export it as jpeg without banding. i chose to accept it for the purpose.

even a 100% jpeg will have compression as far as i understand, and most of all it will be 8bit, which might also cause the problem in very fine tones.

EDIT:
as i mentioned it, this is my own shot i was talking about, it's pretty faint, but it is a very similar thing going on in the sky. in my case producing circles more or less.

 

[silent1]

try exporting it as a tiff or png, if it doesn't show the problem then at least you know it is definitely the jpeg compression.

The exported tiff image looks much better indeed. But then it's 10x bigger.
So if this is a jpeg compression effect, it would have shown up with every (digital) camera I might have used to shoot those pictures?

 

[kbg32]

Color space can definitely produce banding. Also what jpeg quality were you shooting in? Raising it to the highest quality can help reduce the banding, as well as editing in 16 bit or higher in your post processor and dropping it back down to 8 bit for exporting to post online.

Take a look here - http://www.cambridgeincolour.com/tutorials/posterization.htm