Banding issues with jpegs
Hi all Not sure if this went thru or not, sorry if its a repeat Im having a recurring issue with converting tiffs to jpegs thru photoshop. My workflow is: tango 48bit hdr scan -》sf hdr converter, downsample to 24 bits and export into j holmes d cam 3 space -》 pshop edit save as tiff -》downsample and export to srgb jpeg thru save for web. Looks fine on my calibrated monitors, 2.2 gamma set a little warm and a little flat and dark for editing for electronic output. On some monitors, especially mobile devices, Im getting severe banding in some images especially highlights such as the attached images. Can anyone suggest a solution? https://db.tt/qkfGaJb9 https://db.tt/VC4uiszr https://db.tt/VC4uiszr Thanks Brian
On Sep 12, 2014, at 5:37 PM, Brian Aderer <ennigmatick@gmail.com> wrote:
On some monitors, especially mobile devices, Im getting severe banding in some images especially highlights such as the attached images.
First, they are untagged so I assign sRGB. They look fine in terms of banding on this end in Photoshop. The highlights have a fairly obvious color cast (one magenta, one cyan). But no banding. Looking at the Histogram, you're not even close to clipping the highlights. Andrew Rodney http://www.digitaldog.net/
On 13 Sep 2014, at 00:37, Brian Aderer <ennigmatick@gmail.com> wrote:
Can anyone suggest a solution?
Make yourself a set of custom Photoshop curves that will tear the images apart and reveal any banding. I use sine wave shapes which you can create by setting curve points at regular intervals - for example: 0, 10 32, 245 64, 10 96, 245 128, 10 etc Gradients, like your backgrounds, should show smooth waves of vivid colour — but in your case they don’t look good at all and you can see some nasty, uneven and crunchy banding. Apply the curve to the image at each stage in your workflow to isolate the problem. If the raw scan is banding then you may have a problem with the scanner — although I’d suspect that the later application of a poor quality ICC profile is more likely to cause problems like this. Having said that, I have also seen background banding in film caused by degraded soft box diffuser fabrics — so it might be worth scrutinising the original shots to see if you can see any traces of banding which your workflow is enhancing. HTH :-) -- Martin Orpen Idea Digital Imaging Ltd
participants (3)
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Andrew Rodney
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Brian Aderer
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Martin Orpen