Anyone has a 10-bit image lying around?

aevan

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So, news broke out (and it was noticed on these forums even earlier) that the 2014 and 2015 iMac 5K, and the iMac 4K support 10-bit images in Preview and Photos.

While I never missed the 10-bit support on my 5K iMac, I am curious to check if there is any visible difference. So, does anyone have a 10-bit photo or something where such a difference would be visible? I would like to open it in Preview and in some 3rd party viewer still not supporting 10-bit and see if I can spot anything.
 

aevan

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Bottom of this page has a 10-bit test ramp: http://www.imagescience.com.au/kb/questions/152/10+Bit+Output+Support

I believe 10-bit support in El Cap on the new iMacs is not active/incomplete. Let us know what you find.
Thanks!

I opened it in Preview, which supposedly supports 10-bit, and in Photoshop, which, I guess, doesn't. "Ramping" of the gradient is present in both cases and the image looks the same which probably means either of the following:

1. Preview doesn't show PSD files in 10bit even if they are (the article did mention it works with Preview/Photos and RAW files, who knows)
2. The support is not really present in practical terms and it will come at a later date
3. The hardware simply does not support 10bit, it's just the drivers
4. The difference is too subtle for me to see
 

redheeler

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Thanks!

I opened it in Preview, which supposedly supports 10-bit, and in Photoshop, which, I guess, doesn't. "Ramping" of the gradient is present in both cases and the image looks the same which probably means either of the following:

1. Preview doesn't show PSD files in 10bit even if they are (the article did mention it works with Preview/Photos and RAW files, who knows)
2. The support is not really present in practical terms and it will come at a later date
3. The hardware simply does not support 10bit, it's just the drivers
4. The difference is too subtle for me to see
I opened my test image (attached) in Preview after installing 10.11.1 and confirmed support is definitely there on my late 2014 Retina iMac. Check if Pixel Depth: 30-Bit Color (ARGB2101010) in System Information > Graphics/Displays matches yours.
 

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aevan

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I opened my test image (attached) in Preview after installing 10.11.1 and confirmed support is definitely there on my late 2014 Retina iMac. Check if Pixel Depth: 30-Bit Color (ARGB2101010) in System Information > Graphics/Displays matches yours.
Yes, it works. The problem is that it's a bit buggy - I had an external display attached and I was using a 3rd party app (QuickRes) to get that display into retina mode (it is a hidpi screen) and it seemed to have interfered with the Preview app I turned it off and restarted and it's definitely 10-bit. The bands on the grayscale image you attached are gone, and opening the same image in Photoshop (which doesn't support 10-bit yet) shows the bands quite clearly.

For now, only in Preview/Photos, but future OS X versions could bring system wide support. And it's up to Adobe now to implement it in the OS X version of Photoshop, which may happen, like, never - considering how fast they are in addressing El Capitan Photoshop bugs.

Still, it's nice to know the screen is indeed 10-bit. I remember when a lot of people cried for days on these forums how the iMac 5K cannot be a professional device because the screen is not 10-bit. Well, there you go :)

Thanks for the image and info!