16 Bit Printing

[cybis]

For me it indicated that the actual colorspace used for the encoding is not so significant as long as it is big enough to hold all colors of given image.

Unless your only goal is to reproduce art work, I don't think the argument is relevant here. It doesn't matter that the capture or the scene's colors are entirely within a given colorspace. What matters is whether or not a given colorspace can hold the entire output colorspace. This is because processing of the captured image could expand its gamut.

[Paul2660]

As a complete layman when it comes to this type of discussion, would I be wrong in suggesting that this extract from Andrew's link to "Real World Adobe Photoshop" is the simplest argument for using ProPhoto RGB?
 

It doesn't seem to be the to me if the final output is a inkjet print, which is what I am working for.  I don't think Epson can print to the Prophoto RGB color space based on the number of out of gamut softproofs I will get.  Plus if you are out of gamut, then most times reducing saturation ruins the look of the image, thus all the time spent, and converting to Adobe RGB (1998) also seems to lose the look, where as working in the Adobe RGB (1998) space tends to give me images that softproof to the profiles for the 9900.  This just gets worse if you are working with canvas, printing on matte canvas to coat later as the available gamut seems to be much less.  I realize Glossy canvas has a larger working gamut, but there are other issues with glossy canvas that make me stay with matte.  I realize that ProPhoto RGB has Billions of more colors, just can't get it to softproof cleanly very often.


If I could get the Prophoto space to softproof better, I would definitely stay there.

Paul

[digitaldog]

It doesn't matter that the capture or the scene's colors are entirely within a given colorspace. What matters is whether or not a given colorspace can hold the entire output colorspace. T

Both are important. We can't (easily) pick and choose what encoding color space we can use based on the image we might capture. Hence use a big one. Beats using a smaller one where the result is clipping of colors. And that's probably why Adobe raw converters use such a big space.
I suppose if you're in a studio setup, capturing art work, one could use something smaller. But for the rest of us?

[digitaldog]

If I could get the Prophoto space to softproof better, I would definitely stay there.

But you are not using ProPhoto to soft proof, you're using the output profile which like ProPhoto, may contain colors that are outside your display gamut. The limitation is the display and in more ways than just it's gamut. Again, toss colors you can output just so you can see them?

[cybis]

Both are important.

Correct. I meant to say it isn't sufficient for the entire captured gamut to fit within a colorspace. It's necessary but not sufficient...

[Schewe]

It doesn't seem to be the to me if the final output is a inkjet print, which is what I am working for.  I don't think Epson can print to the Prophoto RGB color space based on the number of out of gamut softproofs I will get.  Plus if you are out of gamut, then most times reducing saturation ruins the look of the image, thus all the time spent, and converting to Adobe RGB (1998) also seems to lose the look, where as working in the Adobe RGB (1998) space tends to give me images that softproof to the profiles for the 9900.

I'm not sure how you are soft proofing, which what application and on what display, but I gotta tell you that being concerned about out of gamut color warnings is a wast of time. In Photoshop and Lightroom, OOG is a simple binary in/out indication. It tells you NOTHING about HOW the OOG colors will look. That's what soft proofing is designed to tell you.

I cringe when I hear people say that they try to desaturate OOG colors for the purposes of getting the color in gamut. Of course, that ruins the image...what matters most is deciding which rendering intent will best render the color (in or out of gamut) and what will the image look like when printed. This predictive function of soft proofing allows you to use the limitations of the output media to try to get the optimal output in terms of color & tone.

While ProPhoto RGB certainly has a ton of colors (some imaginary) that the Epson 9900 can't print, there are a lot of potential color that the 9900 CAN print but can't be contained within Adobe RGB. Red, yellows and oranges in particular will be clipped when using ARGB and some of those same colors CAN be printed on the 9900.

While written as an sRGB vs PPRGB discussion, this page: sRGB-VS-PPRGB, the color gamut of ARGB is not hugely better that sRGB and similar issues of gamut clipping can occur.

But hey, if what you are doing is working for you, by all means, keep doing what you are doing with the exception of thinking that viewing out of gamut colors is giving you anything useful. Soft proof? For sure, but get over the OOG habit.

[Paul2660]

Jeff:

In my last post, I used OOG and soft proofing as the same, and that was a mistake.  I never view OOG in CC or LR (not sure how to do it in LR).  By OOG I was referring to the view you get in soft proofing to a paper profile and the soft proof shows a different shade of blue or hue etc.  I have always assumed that this color change when soft proofing to a paper profile in CC or LR implies that the color that has changed is OOG for that paper profile. 

I found that if I stayed in the Adobe RGB (1998) for images that know will be printed on my Epson 9900 or 7800, I run into less issues with color miss matches when soft proofing to the paper profile.  For me most common in blue skies, where I have added a bit of clarity and saturation. 

I am still on a NEC 3090, using Spectraview, and soft proof in CC and LR via the drop downs, using the custom option and then selecting the paper profile I am looking to proof. 

However in my workflow, I never set CC to display OOG.  I just rely on the results of the soft proof.

Paul

[cybis]

In light of the current discussion, I wanted to reproduce the results from the experiment I ran 3 years ago with gradients that showed no difference between 8 bit and 16 bit images.

I found out that it’s actually not entirely correct.  What I can’t see is the difference between a 16 bit image and the same 16 bit image downsampled to 8 bit with dithering. It seems some applications introduce dithering when converting from 16 to 8 bit and some don’t. If the conversion is made without dithering, the resulting prints can show clear banding.
 
LR and PS dither when downsampling, Qimage doesn’t (double bummer).

I’ll run more tests to see if there is any visible difference between Epson 16 bit mode on Mac vs 8-bit with dither.

I apologize if I misled anyone with my previous statements.

[cybis]

LR and PS dither when downsampling

I should add LR and PS dither when converting to 8 bit not just when selecting Image>Mode>8 Bits/Channel but also in the print module if needed unless, I assume, Epson 16-bit mode is active.

[Schewe]

I should add LR and PS dither when converting to 8 bit not just when selecting Image>Mode>8 Bits/Channel but also in the print module if needed unless, I assume, Epson 16-bit mode is active.

Correct...and when done in LR or Photoshop that conversion from 16-bit > 8-bit is done in 20-bit precision...

[cybis]

Correct...and when done in LR or Photoshop that conversion from 16-bit > 8-bit is done in 20-bit precision...

Thanks for the precision.

[JRSmit]

But the capture was of 2D art work? Because I have captures of actual real world stuff and often, depending on subject of course, it falls outside Adobe RGB (1998).

Some examples in this video:
High resolution: http://digitaldog.net/files/ColorGamut.mov
Low Res (YouTube): http://www.youtube.com/watch?v=n0bxSD-Xx-QAnd as illustrated, for that, ProPhoto RGB is necessary or something larger than sRGB or Adobe RGB (1998).

Yes, manmade colours or flowers and sometimes also foliage easily are beyond aRGB.
Then the color encoding/transformation behaviour of the engine together with the quality of profiles come even more into play.

[JRSmit]

Unless your only goal is to reproduce art work, I don't think the argument is relevant here. It doesn't matter that the capture or the scene's colors are entirely within a given colorspace. What matters is whether or not a given colorspace can hold the entire output colorspace. This is because processing of the captured image could expand its gamut.

With my post i was responding more to the point earlier in this thread about transforming to a smaller space for more coding efficiency. Of course for the working space i agree to have a spa e big enough to hold all relevant colorspaces in the image process.
For me i am happy with pRGB.

[Schewe]

For me i am happy with pRGB.

Just to be clear, your reference to pRGB means ProPhoto RGB (PPRGB). Right? Or is there some other "p" out there? :~)

[Bart_van_der_Wolf]

LR and PS dither when downsampling,

Hi,

I'm not sure that is correct, assuming you mean mode change from 16 to 8-bit/channel. The dither option is greyed out for profile conversion in PS when in 16-bit/channel mode. Only when already in 8-bit/channel mode does PS offer an option to dither for profile conversions, in 8-b/ch space.

Are you saying dithering is always added with a mode change? Any references for that? The Color settings preference states that only within 8-bit mode conversions are affected (see attachment).

Cheers,
Bart

[Some Guy]

Just to be clear, your reference to pRGB means ProPhoto RGB (PPRGB). Right? Or is there some other "p" out there? :~)

There is another one out there now and it is pRGB which stands for Printer RGB.  Something Qimage has come out with around version 2014.213 or so.  Somewhere between Adobe RGB and ProPhoto RGB.

More here: http://ddisoftware.com/tech/qimage-ultimate/prgb-same-as-printer-rgb/?PHPSESSID=sqhvan1opdd06lrm0lila1rj32

I've been wondering about it too since I spotted it in the folder.

SG

[Bart_van_der_Wolf]

There is another one out there now and it is pRGB which stands for Printer RGB.  Something Qimage has come out with around version 2014.213 or so.  Somewhere between Adobe RGB and ProPhoto RGB.

Hi,

It (pRGB = Printer RGB) was actually around a lot longer (the pRGB.icm profile on my computer is dated 07 Sept 2007), but it gets automatically installed since version Qimage Ultimate 2014.213. Mike Chaney also mentioned it in his Tech article from 2006, called December 2006: Hype or hero take 2: 16-bit printers.

Cheers,
Bart

[JRSmit]

Just to be clear, your reference to pRGB means ProPhoto RGB (PPRGB). Right? Or is there some other "p" out there? :~)

Indeed i mean prophotoRGB with pRGB.

[cybis]

I'm not sure that is correct, assuming you mean mode change from 16 to 8-bit/channel. The dither option is greyed out for profile conversion in PS when in 16-bit/channel mode. Only when already in 8-bit/channel mode does PS offer an option to dither for profile conversions, in 8-b/ch space.

Are you saying dithering is always added with a mode change? Any references for that? The Color settings preference states that only within 8-bit mode conversions are affected (see attachment).

Hi Bart,

Yes, I'm saying, by default, the conversion from 16-bit > 8bit in PS is done with dithering. There is a way to turn that feature off (but there is probably no good reason to do so): deselect Edit>Color Settings...>Conversion Options>Use Dither (8-bit/channel images).

The option in the screen shot you attached applies only for conversion of image already in 8-bit.

My source for this are my eyeballs. I made a ramp in 16-bit and watched the effect of converting it to 8-bit.

[Bart_van_der_Wolf]

Hi Bart,

Yes, I'm saying, by default, the conversion from 16-bit > 8bit in PS is done with dithering. There is a way to turn that feature off (but there is probably no good reason to do so): deselect Edit>Color Settings...>Conversion Options>Use Dither (8-bit/channel images).

The option in the screen shot you attached applies only for conversion of image already in 8-bit.

Hi,

But that attachment shows the only (CS6 Extended) option related to dithering in the Color settings dialog, and it only applies to conversions from 8-bit to 8-bit ... Do you have another option in your (CC?) version, if so could you post a screen capture so I can see what you are referring to?

Cheers,
Bart


P.S. When I make a gradient in 16-bit ProPhoto RGB and change the mode to 8-bit, no dithering takes place. And while in 16-bit/channel mode, profile conversions also do not add dithering. The only dithering taking place is when the marked option is checked, and only between 8-bit to 8-bit profile conversions.