Banding Question

[Hector1970]

Hi All,

I am experiencing banding in photographs in skies.
Its usually when I convert to black and white using Silver Efex Pro.

I've been using nomorebanding.com to remove banding (I can't actually get the action to work but the step by step of the action works (using added noise).

I was wondering how I can avoid banding in the first place.
I was reading that it's to do with conversion to 8 Bit and that working in 16 bit increases the number of shades of gray available.

Is there something I should be doing?
I shoot sometimes in Raw and sometime JPEG.
Is there things I should consider?
Should I work in TIFF's?
Does anything (say like cleaning the sensor) make it more prone to banding?
I'm not clear what causes banding and whether it's semi illusionary (tricking the eye rather than actually existing)

 

[privatebydesign]

An example always helps because we refer to the same thing with different names and expressions. Anyway, it is probably using 8bit files that s hurting you.

For quality B&W you really need a 16 bit workflow, shoot RAW, open in PS as a 16bit TIFF and you should be good.

 

[Hector1970]

Thanks yes a picture would be good.
I'm not great at adding pictures here.


Here is a link to a picture that has banding - you have to zoom in a bit to see it.

https://www.flickr.com/photos/fergalocallaghan/22671131390/in/dateposted-public/

Could you explain the 8bit / 16 bit issue.

If I go into photoshop and open a raw picture and then go into Nik Silver Efex Pro and save as a JPEG am I in 8 bit mode?

Do I need to save as TIFF before I do anything in Silver Efex.

 

[PhotographyFirst]

Thanks yes a picture would be good.
I'm not great at adding pictures here.


Here is a link to a picture that has banding - you have to zoom in a bit to see it.

https://www.flickr.com/photos/fergalocallaghan/22671131390/in/dateposted-public/

Could you explain the 8bit / 16 bit issue.

If I go into photoshop and open a raw picture and then go into Nik Silver Efex Pro and save as a JPEG am I in 8 bit mode?

Do I need to save as TIFF before I do anything in Silver Efex.

Open the RAW file in Adobe Camera Raw and then export it or open it directly in Photoshop, but with the Bit Depth setting at 16 bit. It needs to be exported as a Tiff file, as JPEG does not allow 16 bit.

That should solve your problems.

If you are not using RAW, but JPEG from the camera, then you are not going to get as good results. You can still try to convert the Photoshop file to 16 bit even though it is from a JPEG. Do that before using the Black and White filter, and you might have less of the issue. It has worked for me in the past.

 

[anthonyd]

You are clearly having unacceptable levels of banding. What camera are you using, what's the firmware on it, and what compression level do you use when you export to jpeg?

 

[Sporgon]

You can still try to convert the Photoshop file to 16 bit even though it is from a JPEG.

You can but you'd be wasting your time.

 

[krisbell]

I frequently encounter banding, and again particularly when converting to black and white. I find 16bit (over 8bit), despite being lauded as a key approach, makes almost no perceivable improvement in the banding. Adding noise definitely helps but of course isnt ideal. ETTR helps, as does keeping exposure adjustments in post to an absolute minimum. Also, if using luminosity masks you can add noise to the mask itself (every little helps). Finally, there is a very real possibility the banding doesnt exist. To be sure you have to view the image at 100% and on a good quality monitor.

 

[bedford]

I think (I'm by no means an expert on this topic) this type of colour banding is more a principal limitation when dealing with discrete values (quantization error) than a flaw in the camera/the sensor. The problem might be pronounced or even provoked when applying digital colour filters.

For example, when applying a "red filter" to an already dark blue sky, the low number of different shades is further reduced by throwing away the blue and the green channel.

You could try to reduce the effect of the filter or add dithering (Floyd-Steinberg) to the final image.

Regards,
Oliver

 

[chauncey]

Let me see if I've got this...sometimes you PP this way, sometimes that way, sometimes another way.
Ostensibly without a clue as to what the outcomes might be. Do you have a clue as to the differences in 8 bit/16 bit mode or...
ProPhoto/sRGB/RGB for that matter.

 

[Don Haines]

When you shoot an image, your sensor records RGB values from the pixels. Depending on your camera you have (approximately) from 10 to 14 bits of resolution...... for the sake of argument, let's say we have 12 bits.

12 bits gives you 4096 different levels of colour for each colour. Figure that as 36 bits for an RGB image and you end up with 4,294,967,296 possible colours for a pixel.

A JPG is encoded as 8 bit colour and you have a maximum of 256 different colours. That is a massive loss of colour information (JPG is reasonably good with brightness information) and the quality of your image will suffer.

This is why you should never save an image that is to be edited as a JPG.... JPG files are the final output for something to be used on "the web" where compression is far more important than resolution or accuracy.

 

[Hector1970]

Thanks for your useful comments and explaining how I might avoid banding.
I appreciate that you took to time to do that.

I still can't work out people line Chauncey - do they get out of the wrong side of the bed or what?
Why bother commenting if that is that is what you are going to contribute.
Thankfully most members here are not like that and give great help and advice.

 

[chauncey]

I guess that I was being excessively subtle...learn the effects of bits/different color spaces thru Google and YouTube.
Develop a consistent workflow.