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Author Topic: Best Working Space For Black And White In Driver  (Read 4950 times)

HowardG

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Best Working Space For Black And White In Driver
« on: September 19, 2016, 10:26:16 PM »

When I had my Epson printer I never really used the ABW mode, especially since most of my monochrome prints were toned. I simply printed them as color images using the paper profile for color printing. I am interested in exploring the black and white mode of my new Canon IPG 2000 with third party papers. I gather this can be done by assigning 'printer manages color' in PS and the black and white mode in the Canon driver and using the custom media settings I made in the Media Config Tool for paper feed etc but obviously not the color icc profile. In addition I have seen articles about linearization by making an icc profile from a series of patch readings.

I am a bit confused though about what the best working space for a file to be in before sending it to the printer for untoned black and white prints using the black and white printing mode in the Canon driver.  Prophoto RGB, Adobe RGB, Grayscale, Gamma 1.8, Gamma 2.2 etc.

I could use some enlightenment as well as an understanding of why one would be better than the others

Thanks

Howard
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HowardG

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Re: Best Working Space For Black And White In Driver
« Reply #1 on: September 19, 2016, 10:36:26 PM »

And of course I am referring to how to send or convert the file after it has been converted to black and white using either PS layers or Nik Silver Efex Pro.

Howard
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keithcooper

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Re: Best Working Space For Black And White In Driver
« Reply #2 on: September 25, 2016, 03:11:11 PM »

I've always used a 2.2 gamma space, but it's based on something I was told years ago, so I'd be very interested to see if there is a definitive answer for this (preferably with a pointer to some available documentation rather than just a newer opinion ;-)

donbga

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Re: Best Working Space For Black And White In Driver
« Reply #3 on: September 26, 2016, 09:06:52 AM »

I've always used a 2.2 gamma space, but it's based on something I was told years ago, so I'd be very interested to see if there is a definitive answer for this (preferably with a pointer to some available documentation rather than just a newer opinion ;-)

Keith,

You know good and well why gamma 2.2 is used. Quit being coy.
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Paul Roark

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Re: Best Working Space For Black And White In Driver
« Reply #4 on: October 05, 2016, 01:38:51 PM »

I use gray gamma 2.2 also.  Like Adobe RGB, it uses the gamma 2.2.  I have the cameras set to Adobe RGB.  I would think keeping things most consistent would be a good goal.  I suspect every adjustment involves some information loss.  (It also displays well on the web.)

Paul
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roscoetuff

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Re: Best Working Space For Black And White In Driver
« Reply #5 on: December 21, 2016, 08:56:41 AM »

FWIW, I'm using my camera on AdobeRGB. As I understand, Gray Gamma is a workspace within AdobeRGB, so this will work fine. I'm using Capture One to convert the image to B&W, and process to a TIFF which is then opened in an ImagePrint page set up for printing "Gray" color space. The image itself is then color corrected to a Narrow Gamut - which refines the control over the gray / black / white tone ranges. This seems to work and create a beautiful image space.
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texshooter

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Re: Best Working Space For Black And White In Driver
« Reply #6 on: July 22, 2017, 07:06:46 PM »

Ian Barber recommends doing all B&W conversions in the Prophoto 1.8 gamma  working space.

I'm skeptical about that because no monitor can display Prophoto colors. You would be editing with colors you can't see. I would worry about huge shifts in your B&W conversion (which you toiled so hard to perfect) the instant you switch to aRGB to prep for ABW printing..  A better approach I suspect would be to do all the B&W conversion in aRGB, not Prophoto.

https://www.digitalblackandwhite.co.uk/editing-color-space-for-printing.html
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keithcooper

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Re: Best Working Space For Black And White In Driver
« Reply #7 on: July 22, 2017, 07:45:28 PM »

Ian Barber recommends doing all B&W conversions in the Prophoto 1.8 gamma  working space.

I'm skeptical about that because no monitor can display Prophoto colors. You would be editing with colors you can't see. I would worry about huge shifts in your B&W conversion (which you toiled so hard to perfect) the instant you switch to aRGB to prep for ABW printing..  A better approach I suspect would be to do all the B&W conversion in aRGB, not Prophoto.
Nope - i've always preferred to use a colour image in prophoto - so as to keep the maximum range of colours that I can choose to use in my B&W conversion.

Finer gradations of colour that may be lost in a smaller space can (if you want) become different grey values.

The fact that my monitor can't display those colours is completely irrelevant since I'm producing a B&W image. You could work on a monitor with sub - sRGB gamut, if it had good greyscale performance.




texshooter

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Re: Best Working Space For Black And White In Driver
« Reply #8 on: July 22, 2017, 08:14:34 PM »

Nope - i've always preferred to use a colour image in prophoto - so as to keep the maximum range of colours that I can choose to use in my B&W conversion.

Finer gradations of colour that may be lost in a smaller space can (if you want) become different grey values.


I understand your point about potentially yielding more variations of grey values by working in Prophoto. But once you convert to aRGB after having completed the B&W process in Prophoto, the RGB eyedropper  number value of each pixel will change (as they always do when you switch colorspaces).  You will be left with contrast shifts that need to be fixed. But you wouldn't know how to fix those contrast shifts because changing colorspaces doesn't change how the image looks on screen but how it prints out.  R=G=B=110 under Prophoto becomes R=G=B=118 under aRGB. They look the same on screen but the ABW driver prints them differently.
« Last Edit: July 22, 2017, 09:12:52 PM by texshooter »
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keithcooper

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Re: Best Working Space For Black And White In Driver
« Reply #9 on: July 23, 2017, 04:19:12 AM »

I understand your point about potentially yielding more variations of grey values by working in Prophoto. But once you convert to aRGB after having completed the B&W process in Prophoto, the RGB eyedropper  number value of each pixel will change (as they always do when you switch colorspaces).  You will be left with contrast shifts that need to be fixed. But you wouldn't know how to fix those contrast shifts because changing colorspaces doesn't change how the image looks on screen but how it prints out.  R=G=B=110 under Prophoto becomes R=G=B=118 under aRGB. They look the same on screen but the ABW driver prints them differently.

That is so - I never mentioned subsequent editing and or printing - the point is what space to work in for the conversion stage.

I just prefer to have as much of the camera data to use as possible.  Of course, this depends on how you convert the RAW file - many of my larger images were converted to B&W after using DxO Optics Pro, where the large space is not available (it's usually the resulting print that counts not the numbers ...)

Just that as a starting point I'll work on prophoto. it's for B&W so the precise display of the colours is irrelevant, especially since the best looking colour versions of a raw file does not always equate with the best looking B&W version

Subsequently I convert to G2.2 for most BW editing (in 16 bit) so any such changes are not relevant to me.

Interestingly enough I have an EpsonP5000 here at the moment for my next review.

I've been looking at aspects of B&W printing of late, whether with a custom icc profiles (~3k patches) or ABW. Also with pre-print modification of linearity with PS curves and QTR icc profiles.

Some of my B&W testing ... It certainly helps having a hefty supply of free ink and paper to try this ;-)  I'm measuring the step wedge on my B&W test image with an i1iO - the whole image is there to remind me to look at the images as well as the numbers ;-)

As well as the review I'll be doing quite a bit of B&W specific stuff - if anyone has any specific questions - do feel free to contact me directly as well, since I've got the printer until September (yay! - it's working a treat - no clogs)

Alan Goldhammer

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Re: Best Working Space For Black And White In Driver
« Reply #10 on: July 23, 2017, 07:38:59 AM »


Interestingly enough I have an EpsonP5000 here at the moment for my next review.

I've been looking at aspects of B&W printing of late, whether with a custom icc profiles (~3k patches) or ABW. Also with pre-print modification of linearity with PS curves and QTR icc profiles.

As well as the review I'll be doing quite a bit of B&W specific stuff - if anyone has any specific questions - do feel free to contact me directly as well, since I've got the printer until September (yay! - it's working a treat - no clogs)
It would be most interesting to hear your thoughts on printing via the traditional Epson driver and the ABW (with modifications as noted above).  Mark Segal has done some comparisons in his recent reviews.  I assume your custom icc profile (the 3k patch set) contains a B/W step gradient to assist in B/W printing.  This is pretty much what I do when I prepare profiles using ArgyllCMS (51 step B/W patch set).

Alan
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keithcooper

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Curves/profiles/ABW
« Reply #11 on: July 23, 2017, 08:48:21 AM »

It would be most interesting to hear your thoughts on printing via the traditional Epson driver and the ABW (with modifications as noted above).  Mark Segal has done some comparisons in his recent reviews.  I assume your custom icc profile (the 3k patch set) contains a B/W step gradient to assist in B/W printing.  This is pretty much what I do when I prepare profiles using ArgyllCMS (51 step B/W patch set).

Alan
Actually, I was pleased to see that my normal A3+ profile making target measured on an i1 iSis XL works just fine (~3k) and that making a special one for B&W (normal colour set (~1k) plus 0-255 grey and near greys gave very little improvement if any, with i1profiler - there are not the adjustment options available in i1profiler when making profiles to get any real benefit (life has consistently been too short to get to grips with argyllCMS- YMMV)

Whilst I've lots more prints to try, I'm finding that ABW works best on shiny papers (PK) but with matt papers such as Innova IFA-11 (-very- similar to Epson HPN) I'm leaning towards using my own colour icc profile with a simple PS curve (only 3-5 points specified).

51 points (scanned with i1iO2 3x averaged) gives a good solid data set to see variation of linearity, but a simple curve works just fine - making dozens of prints and actually looking at them is is a powerful reminder that chasing the numbers can be rather futile after a while.

This is an ACV curve for IFA-11 - one of the more complex ones. Curve points are entered manually from a normalised set of readings of a 51 step wedge (I just paste the saved measurement data into a spreadsheet, to create a set of 'L' values normalised to 0-100)

I'm minded to wonder if more complex solutions seem more disposed to those not actually wanting to print photos ;-) :-)

But seriously, an 'excess' of measurements can exacerbate residual measurement errors and minor variations in linearity, producing what might seem more accurate solutions, but when combined with the vagaries of 8 bit curves produce worse looking prints - every time I did a print with a curve/profile/setting, I looked first at the bullseye target on the test print. Several good looking solutions showed up slight banding.

I was asked why I wanted a linearised print output, since you could say that perceptually, there should be curves in the response... From my POV I want to start at linear and add those curves based on image content, paper type and viewing conditions, not have them 'baked in'  - it's much like my approach to print sharpening for larger images - I want the option to have absolutely none at all in parts of the image.

texshooter

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Re: Curves/profiles/ABW
« Reply #12 on: July 23, 2017, 09:26:17 PM »

but with matt papers such as Innova IFA-11 (-very- similar to Epson HPN) I'm leaning towards using my own colour icc profile with a simple PS curve (only 3-5 points specified).

Are you saying you don't print with the ABW driver for matte papers?

This is an ACV curve for IFA-11 - one of the more complex ones. Curve points are entered manually from a normalised set of readings of a 51 step wedge (I just paste the saved measurement data into a spreadsheet, to create a set of 'L' values normalised to 0-100)

How do you get from the Excel table of L* values to the .ACV file? 
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keithcooper

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Re: Curves/profiles/ABW
« Reply #13 on: July 24, 2017, 05:52:44 AM »

Are you saying you don't print with the ABW driver for matte papers?

How do you get from the Excel table of L* values to the .ACV file?

No, I'm saying that in my current tests with the P5000 I'm finding that the results I'm getting with a few specific matt papers with my own icc profiles show no advantage in using ABW.

How much I care to generalise this is as yet unknown... ;-)

I look at the figures and the shape of the curve they suggest, and create one 'by hand' - no software, just an appreciation of what the numbers are saying about which bits are too bright and which are too dark.

I'll try and explain it in more detail when I write it up, but a simple example would be (using my normalised 0-100 'L' values - NOT the measured L) where light tones are too light and dark tones to dark. At some point we have a point where the curve of actual vs measured 'L' values crosses the straight line between 0 and 100, so I place a point on the curve at that point - lets say 'L' = 40 (remember - normalised 'L' numbers) I add a point in the lighter area to darken things, and one in the darker area to lighten things (0 and 100 being fixed) Those points are not just guesswork - I take a desired input point, say K=80, and use my measured data to see that that an input of 74 is needed to get an output of 'L'=20  (remember that K=100 is 'L'=0). This gives a point for the curve in=80|out=74  - this helps address the darker parts of the image.

I'll have examples and pictures when I write it up!

I'm printing with my colour profiles relcol+BPC, so there is non linearity between the BPC and whatever X-rite puts into its profiles - this is also what the curve is correcting

I am not currently suggesting people change what they do - this is one paper.

As an aside, I was truck with the similarity to one of the oldest article on the Northlight site, which I wrote back in 2004, using a desktop scanner for just such curve making
http://www.northlight-images.co.uk/better-digital-black-and-white-printing-on-your-inkjet-printer/

For those wanting some 'real numbers' ;-) Two sets of measurements from the IFA-11 ('Epson HPN') after running through QTR's profile making (it's a nice quick way to visualise the curves, even if I'm not using the profile)



Alan Goldhammer

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Re: Curves/profiles/ABW
« Reply #14 on: July 24, 2017, 07:23:21 AM »


I'm printing with my colour profiles relcol+BPC, so there is non linearity between the BPC and whatever X-rite puts into its profiles - this is also what the curve is correcting


This is the one advantage of ArgyllCMS.  I can put in the 51 step B/W patch set during the profiling process and get the necessary linearization for B/W printing.  I've never used the X-Rite profile software so I'm not able to comment further and perhaps what Keith notes is how one needs to deal with the issue.

Last week I just finished profiling Moab Entrada and Moab Somerset Rag, both matte papers, using the above technique.  I've printed out a couple of my B/W prints and like the way that they look. 
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keithcooper

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Re: Curves/profiles/ABW
« Reply #15 on: July 24, 2017, 07:58:23 AM »

This is the one advantage of ArgyllCMS.  I can put in the 51 step B/W patch set during the profiling process and get the necessary linearization for B/W printing.  I've never used the X-Rite profile software so I'm not able to comment further and perhaps what Keith notes is how one needs to deal with the issue.

Last week I just finished profiling Moab Entrada and Moab Somerset Rag, both matte papers, using the above technique.  I've printed out a couple of my B/W prints and like the way that they look.
How are you using your profiles - what rendering intent?

Have you measured the linearity -after- printing with a profile?

Alan Goldhammer

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Re: Curves/profiles/ABW
« Reply #16 on: July 24, 2017, 11:00:21 AM »

How are you using your profiles - what rendering intent?

Have you measured the linearity -after- printing with a profile?
Printing out of LR and I use relative colormetric.  Yes, I check the profiles after creation with both the ArgyllCMS profcheck tool that prints out all the values in an Excel spreadsheet that allows me to see how the patch set turned out.  I've also printed out some B/W patch sets and read them manually.  Very good linear behavior.  It should be noted that this is only for printing without the ABW driver.  I've found for matte papers, the extra black from the ABW driver isn't all that necessary.

EDIT:  Attached is the image that I use to test papers.
« Last Edit: July 24, 2017, 11:03:36 AM by Alan Goldhammer »
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keithcooper

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Re: Curves/profiles/ABW
« Reply #17 on: July 24, 2017, 11:30:07 AM »

Printing out of LR and I use relative colormetric.  Yes, I check the profiles after creation with both the ArgyllCMS profcheck tool that prints out all the values in an Excel spreadsheet that allows me to see how the patch set turned out.  I've also printed out some B/W patch sets and read them manually.  Very good linear behavior.  It should be noted that this is only for printing without the ABW driver.  I've found for matte papers, the extra black from the ABW driver isn't all that necessary.

How linear are the -measured- values at the dark end after printing?  Are you using BPC or are you taking care of this in profile building? (I've not checked this at all with LR - I'm using PS CS6 for everything)

Also - What printer is this with?
I'm not seeing darker blacks with the ABW - depends on paper though, but there is no -obvious- advantage from ABW on the P5000

Alan Goldhammer

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Re: Curves/profiles/ABW
« Reply #18 on: July 24, 2017, 12:37:25 PM »

How linear are the -measured- values at the dark end after printing?  Are you using BPC or are you taking care of this in profile building? (I've not checked this at all with LR - I'm using PS CS6 for everything)

Also - What printer is this with?
I'm not seeing darker blacks with the ABW - depends on paper though, but there is no -obvious- advantage from ABW on the P5000
Epson 3880 is the printer.  I also don't see darker blacks with matte paper; only with glossy paper.  I pretty much only use ABW for papers such as Ilford Gold Fiber Silk and Museo Silver Rag.  Any other B/W printing is done through the normal pathway.  BPC is always on in LR.  I'll need to look up the measured patch sets and get back to you on that. 
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texshooter

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Re: Best Working Space For Black And White In Driver
« Reply #19 on: August 01, 2017, 06:16:57 PM »

I'm curious why there is no 2.2 gamma version of the Prophoto working space? Prophoto only comes in one flavor, namely 1.8 gamma.  If there were a Prophoto 2.2, then ABW users would not have to convert to aRGB (or sRGB, or Gray Gamma 2.2) before printing to the ABW driver. 
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