Finally, 30 bit color on my Mac

[jerryrock]

The combination of Mac OS El Capitan and Photoshop CC 15.1 now produces true 30 bit color.

Peta Pixel article

[digitaldog]

The combination of Mac OS El Capitan and Photoshop CC 15.1 now produces true 30 bit color.

So much conflicting info. First of all, I was told that for this to really occur, I'd need a video card that supports high bit. The examples I was provided were specific: ATI FirePro, some of the newer Intel Iris Pro based chipsets. I'm using an older MacBook Pro (Retina, Early 2013) with a NVIDIA GeForce GT 650M 1024 MB. I did see banding on the now famous test file with the latest version of CC released last week. But after reading the article you provided (thanks!) and clicking on the 30-bit display check box, banding is gone. So I'm happy but not sure what's going on here . Can't argue with the better results I see on-screen!

[digitaldog]

Something may not be kosher here. I see NO banding on the MacBook Retina display with the new setting invoked. I do see banding when off. Is the MacBook Retina a high bit panel (news to me)? If not, should we be suspicious that Adobe is doing some kind of dithering here to smooth everything out?

[GWGill]

Is the MacBook Retina a high bit panel (news to me)? If not, should we be suspicious that Adobe is doing some kind of dithering here to smooth everything out?

Screen capture to check ? (Are 30 bit screen captures possible ?)

[Bart_van_der_Wolf]

Something may not be kosher here. I see NO banding on the MacBook Retina display with the new setting invoked. I do see banding when off. Is the MacBook Retina a high bit panel (news to me)? If not, should we be suspicious that Adobe is doing some kind of dithering here to smooth everything out?

Hi Andrew,

Don't know what to think of that. I was pleased that you were apparently able to get a 30-bit performance, but was puzzled by the fact that you say that your nVidia graphics card is not a Quadro family card type (which according to nVidia is the only one that provides 30-bit output).

If nVidia say that it is not possible, yet you see what seems to look like 30-bit smooth gradients, then something in El Capitan, or in PS must do something to make it look like it is 30-bit.
Since the Petapixel article says that they got confirmation from Adobe that they changed something, I also get a suspicion that something else is happening, like dithering. Puzzling, to say the least.

Cheers,
Bart

[digitaldog]

Screen capture to check ? (Are 30 bit screen captures possible ?)

Not sure what you're asking for. You want screen capture from both NEC and Retina (not sure that mechanism will produces what I see). Are 30 bit screens possible? Well the SpectraView, depending on model is 12-14 bits per color as spec'ed. It's the Retina display that has me scratching my head.

[digitaldog]

Since the Petapixel article says that they got confirmation from Adobe that they changed something, I also get a suspicion that something else is happening, like dithering. Puzzling, to say the least.

I got this info (don't ask where) :

I believe that Apple applies dithering (invisible to Photoshop) in some cases when the panel doesn’t support it. I don’t know how to distinguish "true" 30 bit from dithered 24 bit.
Great, this could all be smoke and mirrors. But then on both the NEC PA and Retina, the gradients look smoother.

[Bart_van_der_Wolf]

I got this info (don't ask where) :

I believe that Apple applies dithering (invisible to Photoshop) in some cases when the panel doesn’t support it. I don’t know how to distinguish "true" 30 bit from dithered 24 bit.
Great, this could all be smoke and mirrors. But then on both the NEC PA and Retina, the gradients look smoother.

If true, this means that the Mac OS version El Capitan added dithering, and Adobe enables/disables it with the 30-bit setting in Photoshop. No wonder that Adobe didn't want to mention it as really supporting 30-bit output ..., I appreciate their honesty.

Cheers,
Bart

[digitaldog]

If true, this means that the Mac OS version El Capitan added dithering, and Adobe enables/disables it with the 30-bit setting in Photoshop. No wonder that Adobe didn't want to mention it as really supporting 30-bit output ..., I appreciate their honesty.

Let's not jump to any conclusions just yet. Since day one, when the rumor was OS X had high bit support, there's been a lot of speculating and very little info from those who really know.
A fellow inside a company who is in the know (not Apple or Adobe) summed it up well:

Welcome to the strange world of high bit color :-) It's really difficult to know who is doing what in the video chain, so it leads to a lot of confusion and guesswork.

[digitaldog]

One other item to consider. Prior to OS X 10.11 and the last update to Photoshop, I saw very slight banding on the gradient test file we've been told to use to evaluate a high bit video path. Now I don't see that banding. Whatever Apple and/or Adobe is doing gives the illusion of what a high bit video path is supposed to provide when viewing high bit data. So while we may never know what's going on under the hood, this is an improvement I welcome. With high bit data, we shouldn’t see banding. Now we don't.

[jerryrock]

Looking at the graphics section of the computer information on my MacPro 6,1 it appears an actual 30 bit color path is being utilized.

[digitaldog]

Looking at the graphics section of the computer information on my MacPro 6,1 it appears an actual 30 bit color path is being utilized.

My MBP shows the same despite that card not supposedly supporting a high bit path. So I'm kind of taking it with a grain of salt unless indeed, the NVIDIA GeForce GT 650M 1024 MB does have the goods.

[Bart_van_der_Wolf]

Looking at the graphics section of the computer information on my MacPro 6,1 it appears an actual 30 bit color path is being utilized.

AFAIK, only an ATI/AMD FirePro card, or an nVidia Quadro card, can offer a 30-bit output path and drivers (in principle only over a DisplayPort interface).

So your setup might allow it, if the drivers are instructed to do so.

Cheers,
Bart

[Czornyj]

rMBP is very linear (TRC is close to γ2,2 @D65), so I wouldn't be suprised if it had 10 bit panel (or 8bit+2bit HiFRC like in NEC PA 24-27", which is virtually indistinguishable from real 10 bit panel like in NEC PA302W).

Ironically, my rMBP15 '15 still doesn't support 30-bit color path (as well as split view)