10-bit color using PsCC2015.1, OS X 10.11.1 and 27" 5K Retina iMacs?

[Ellis Vener]

One of the new aspects of  the OS X version of Photoshop CC2015.1 is that it is 10-bit per channel (BPC)  capable (go to  Preferences> Performance > GPU enabled and > Advanced and switch on the 30-bit Display option

 And we know that the newest 5K Retina  iMacs running OS X 10.11.1 are 10 BPC as well.

But what about older 5K Retina iMacs? I work on a late 2014 27" retina iMac with the older AMD Radeon R9 M295 GPU, but I was concerned that the hardware (GPU and the Display itself) , were not 10-bit per channel capable.

So first I took a look at the Graphics/Display info for this iMac and lo and behold it says that the pixel depth for both my iMac's Display is "30-Bit (ARGB2101010)".

To confirm this I called Apple Support and they confirmed that this machine is also  fully 30 bit capable.

[digitaldog]

So first I took a look at the Graphics/Display info for this iMac and lo and behold it says that the pixel depth for both my iMac's Display is "30-Bit (ARGB2101010)".

I see the same on my MacBook Pro but alas, it's not supporting 10-bit color, easy to test in the latest version of Photoshop CC using this document: 10 bit test ramp.zip

To confirm this I called Apple Support and they confirmed that this machine is also  fully 30 bit capable.

I would suggest they are wrong 

[Ellis Vener]

will try that next.

[Jack Hogan]

10-bit video finally makes it to Apple?  Software, drivers, look up table, cable, monitor all need to support 10 bits. It usually falls apart somewhere along the chain unless special care is given to the choice of each component.  I can see getting around the problem with new all-in-ones.  Otherwise my guess is that it will require troubleshooting before (and if) it works.

[Ellis Vener]

I see the same on my MacBook Pro but alas, it's not supporting 10-bit color, easy to test in the latest version of Photoshop CC using this document: 10 bit test ramp.zip

 I would suggest they are wrong 

Andrew,

In PsCC 2015.1 with 30-bit Display enabled on the 27" Retina iMac,   the test file  appears to be completely smooth with no banding. I have looked at it  everything from 50% to 1600% scaling
 

[jrp]

In my case it is not smooth when first opened (showing a crop tool overlay) but gets smooth when that is applied.  (On a Mac Pro)

[digitaldog]

In PsCC 2015.1 with 30-bit Display enabled on the 27" Retina iMac,   the test file  appears to be completely smooth with no banding. I have looked at it  everything from 50% to 1600% scaling

The CC release this week (CC 2015 16.1) is supposed to enable Photoshop on Mac for high bit video path according to those I've talked to. If you see NO banding on that test image, it's working. But according to Adobe, this means that 16 bit files displayed at 100% up until 66% will shovel extra bits to the screen so if you're not seeing banding at differing zoom ratio's, that sounds somewhat suspect.
On my MacBook Pro, (NVIDIA GeForce GT 650M 1024 MB) with that new version and a SpectraView, I see very, very slight banding of that test image at 100%. Supported hardware (confirmed so far: ATI FirePro, some of the newer Intel Iris Pro based chipsets). I don't have those cards so it's a no go.

[Ellis Vener]

The CC release this week (CC 2015 16.1) is supposed to enable Photoshop on Mac for high bit video path according to those I've talked to. If you see NO banding on that test image, it's working.

This indeed the version of Photoshop CC 2015 I'm now working in.

But according to Adobe, this means that 16 bit files displayed at 100% up until 66% will shovel extra bits to the screen so if you're not seeing banding at differing zoom ratio's, that sounds somewhat suspect.

Could you please clarify? Is 66% a typo?

On my MacBook Pro, (NVIDIA GeForce GT 650M 1024 MB) with that new version and a SpectraView, I see very, very slight banding of that test image at 100%. Supported hardware (confirmed so far: ATI FirePro, some of the newer Intel Iris Pro based chipsets). I don't have those cards so it's a no go.

[digitaldog]

Could you please clarify? Is 66% a typo?

I don't think so. I was told specifically that: 16 bit files displayed at 100% up until 66% will shovel extra bits to the screen.
It leads me to believe, as we've seen in the past, the zoom ratio is important. But since I don't have a system that conforms, I can't test. 

[Ellis Vener]

At 50% I see banding.  At 66.67% and up, no banding. How do I make a larger test file? The one in your link is only 1024x1024 pixels and in sRGB

[digitaldog]

At 50% I see banding.  At 66.67% and up, no banding. How do I make a larger test file? The one in your link is only 1024x1024 pixels and in sRGB

I'd just make a 16-bit black to white gradient at whatever size you wish.

[digitaldog]

I see no banding on the gradient test image in Lightroom 6.3 in Develop module. I do see it (as somewhat expected) in Library module which uses a different preview path. Anyone want to test and confirm LR 6.3 *appears* to also support this new functionality?

[Yahor Shumski]

I see no banding on the gradient test image in Lightroom 6.3 in Develop module. I do see it (as somewhat expected) in Library module which uses a different preview path. Anyone want to test and confirm LR 6.3 *appears* to also support this new functionality?

Andrew,
The gradient looks smooth in Lightroom version CC 2015.3 but in Develop mode only. I am on PC.

[digitaldog]

Andrew,
The gradient looks smooth in Lightroom version CC 2015.3 but in Develop mode only. I am on PC.

That's supposedly due to dither added in Develop for a preview so the question is, is this the same dithering as Photoshop CC and does it make a difference if this is dither to clean up the gradient or a true high bit video path we're seeing?

[Yahor Shumski]

That's supposedly due to dither added in Develop for a preview so the question is, is this the same dithering as Photoshop CC and does it make a difference if this is dither to clean up the gradient or a true high bit video path we're seeing?

The equipment I use is 10-bit ready, we can only guess at the moment.

[Yahor Shumski]

The equipment I use is 10-bit ready, we can only guess at the moment.

An update here.
I have two monitors side by side. NEC PA272W (10-bit) and 2090UXi (8-bit).
In Photoshop I see banding on 8-bit monitor and none on another one. So 10-bit pipeline works as expected here.
However behavior in Lightroom is different, the gradient is smooth on every monitor rising the question about dither in use.

[digitaldog]

In Photoshop I see banding on 8-bit monitor and none on another one. So 10-bit pipeline works as expected here.
However behavior in Lightroom is different, the gradient is smooth on every monitor rising the question about dither in use.

Thanks, that's useful to know. It's been stated by Adobe that LR does dither.

[AlterEgo]

It's been stated by Adobe that LR does dither.

LR and ACR both ...

[digitaldog]

LR and ACR both ...

Seems that way now that I just checked it. IF 30-bit option is OFF, I see banding in PS but not ACR (either using as a filter or opening the doc 'As Camera Raw".