Banding / blotchy in the darks and shaddows - help please!

[nells8486913]

I'm an equine photographer and do a lot of photos of portraits of horses on black backgrounds. To make the photos more interesting I like to give a backgrounds some lighter areas but I have an issue with the darks and lights on the background looking blotchy or sometimes have banding. I have a decent understanding of photoshop but certainly not an expert. However I have a feeling this might be a workflow issue.

I've posted the final image which hopefully you can see the issue.

My workflow for this image is:

- Clean up the background using a combination of spot heal, clone and healing brush

- Camera raw filter as a smart object to make adjustments to colours, lights, darks etc

- Then add some minor adjustments using curves etc.

On a good screen the image doesn't look too bad but my printer man tells me the patchy background will be very noticeable when printed. Am I getting this issue because I use camera raw filter? Does this somehow reduce the quality? My starting point is a raw image. 

Thank you to anyone that can offer some help as this is driving me mad!

(I've made the image a bit brighter that it should be just so it's easier to see the issue)

[D Fosse]

Three things to note here:

• If you open in 8 bit depth, there are only 256 discrete steps from black to white (per channel). In other words, there is real banding in the image data, and as you work it accumulates. Work in 16 bit depth (32768 steps per channel). If you need to output an 8 bit file, convert as the very last step.
• Even if your image is 16 bit, your display path is still 8 bit! That means you will see banding on screen even when there is none in the data. This can get more pronounced with a bad monitor profile, calibration tables in the video card, an inferior display panel (laptops!) etc. The cure for that is a 10 bit capable monitor (expensive).
• Jpeg compression exaggerates banding, because it compresses the color component much more aggressively than the luminance component. This frequently causes color banding.

[nells8486913]

Thank you for you comments D Fosse that's really helpful. I've just both my lightroom and photoshop settings and they are both set to 16 bit.

Short of buying an expensive monitor I suppose it would be helpful to do some test prints to see what they look like or look on my printer chap's monitor as I know he has an all singing one!

Can I ask about using the camera raw filter after bringing into photoshop after doing my clean up - would this cause any issues? I know most people use camera raw in lightroom first before bringing into photoshop but I prefer to clean up getting rid of disctractions etc first.

[D Fosse]

Actually, you get the best quality by far if you do as much as possible in the Camera Raw processor first (or Lightroom if you use that; they're equivalent), and then open into Photoshop to finish up. The reason is that a raw file has a much bigger dynamic range and a lot more underlying data to draw from. You have much more editing headroom in a raw file. The secret is the linear tone curve (not gamma encoded) which gives room for a very extended dynamic range.

Once you open as an RGB file in Photoshop, that "hidden" data is discarded, and at that point what you see is what you have. So it needs to be optimal.

The Camera Raw filter called from within Photoshop is not the same thing. That's just a small subset where the file comes in late in the pipeline. It basically does what any other adjustment or filter does, from a technical quality perspective.

As long as you open as 16 bit from ACR/Lr you won't lose anything. But you won't be able to pull and recover data as you can with a raw file.

[nells8486913]

Thank you so much for explaining this. I had a feeling this was the case, I was just hoping it wasn't! It's all good though, it means I need to stop getting by and start improving my photoshop skills now I have the basics 🙂

[NB, colourmanagement]

@nells8486913  If issues are appearing after you do a late step of lightening the image background etc.

then I'd do that lightening step first and alter / retouch / clone afterwards, that way you can see what you're doing better

I hope this helps
neil barstow, colourmanagement net - adobe forum volunteer - co-author: 'getting colour right'
google me "neil barstow colourmanagement" for lots of free articles on colour management