sRGB or Adobe
Jun 1, 2015 07:39:36 #
burkphoto wrote:
And some (graphic arts) printers use raster image processors that take in sRGB or Adobe RGB files, and separate them "on the fly", applying a profile for the EXACT paper stock and inks in use! Essentially, that's what an inkjet printer does in the photo lab world.
Making CMYK separations in Photoshop is "so 1990's."
Making CMYK separations in Photoshop is "so 1990's."
However for some masking applications, using CMYK channels offers additional mask fine tuning options.
Jun 1, 2015 08:38:36 #
Jun 1, 2015 08:39:52 #
Gene51 wrote:
However for some masking applications, using CMYK channels offers additional mask fine tuning options.
It does. But as soon as you convert to CMYK, you've shrunk your color gamut significantly. It's okay though, if your target needs to be in CMYK, and you use a conversion profile for the press conditions...
Jun 1, 2015 08:49:30 #
burkphoto wrote:
It does. But as soon as you convert to CMYK, you've shrunk your color gamut significantly. It's okay though, if your target needs to be in CMYK, and you use a conversion profile for the press conditions...
I used to use it for contrast masking - as long as you don't save anything, the color mode is not affected. Besides, you can duplicate the file, create the mask in CMYK, save it and copy it to the RGB version. Either way, nothing is lost.
Better yet, use Remask from Topaz or Perfect Mask functionality in On1 - much better masking, faster results. But this diverges from the main topic of this thread.
I routinely edit and sharpen in Lab mode - same thing - if you don't save it nothing is lost.
Jun 1, 2015 09:00:10 #
Gene51 wrote:
I used to use it for contrast masking - as long as... (show quote)
Thanks for the clarification.
Jun 2, 2015 20:07:39 #
romanticf16
Loc: Commerce Twp, MI
nikonwaddy wrote:
Gene51...why use sRGB for printing...why not RGB....????
Because all labs that print on photo paper calibrate their equipment to sRGB. If the lab is using a 6 or 8+ Pigment printer you can sent an Adobe file, as they can reproduce a larger color gamut with that equipment. Sending the wrong colorspace for the lab's printer will yield a negative quality result in their output.
Jun 3, 2015 05:22:52 #
romanticf16 wrote:
Because all labs that print on photo paper calibrate their equipment to sRGB. If the lab is using a 6 or 8+ Pigment printer you can sent an Adobe file, as they can reproduce a larger color gamut with that equipment. Sending the wrong colorspace for the lab's printer will yield a negative quality result in their output.
Gamut should not be confused with color space. They are different.
Jun 3, 2015 06:55:43 #
Gene51 wrote:
Gamut should not be confused with color space. They are different.
Gene51...Would you care to elucidate.....I have always thought off color space as something of a proprietary pie tin and gamut as how much pie was in the tin.
Thx....
Jun 3, 2015 07:25:48 #
nikonwaddy wrote:
Gene51...Would you care to elucidate.....I have always thought off color space as something of a proprietary pie tin and gamut as how much pie was in the tin.
Thx....
Thx....
http://www.drycreekphoto.com/Learn/color_spaces.htm
Jun 4, 2015 19:57:35 #
romanticf16
Loc: Commerce Twp, MI
Gene51 wrote:
Gamut should not be confused with color space. They are different.
I didn't. I believe I made 2 statements: send the proper Colorspace for how the lab prints or there will be issues; and 6 and 8 color pigment printers can reproduce a higher gamut of Adobe RGB vs sRGB's smaller gamut.
Jun 4, 2015 20:45:53 #
I want to thank all of you, especially Gene51, for giving me a little better handle on color home printing. I monitor on an Asus ProArt 1920x1200 and calibrate with a Spyder 4. the monitor does display in Adobe RGB among others. Unfortunately I discovered to late that my Canon Pro 1 uses the other brand to calibrate it to the monitor. So far the only problem is in brightness levels but I am slowly getting that in control. I print at 11X14 on Red River paper with their ICC profiles and 11X14 hack..Canon does not make an 11X14 paper. My main work is hobbyist art nude in my small home studio with controlled lighting so no huge dynamic range.
Again, Thank y'all from this old Austin dude....
Again, Thank y'all from this old Austin dude....
Jun 4, 2015 21:07:57 #
nikonwaddy wrote:
I want to thank all of you, especially Gene51, for... (show quote)
Use 80 cda/m^2 for white point and .4 ca/m^2 for black - that should put you in the brightness ballpark.
Jun 4, 2015 21:40:12 #
Gene51 wrote:
Use 80 cda/m^2 for white point and .4 ca/m^2 for black - that should put you in the brightness ballpark.
Thank you friend, and I mean that, if I knew what you were saying I would leap on it but afraid you are a couple of light-years ahead of me in tech. What I do is edit in ACR/PS CC where among other things I crop to 11X14, do other refine edits, save to to PSD and print from there. Generally what I do is after I crop and edit to 11x14, is I print to a 4X6 to check color and brightness. Usually what I find is that I bump the brightness in PS by an order of 10 and print to achieve what I see on my monitor....I do not save this..but remember it for future prints.
Thanks for all your insight and help
Jun 4, 2015 23:23:48 #
Gene was giving you reference points for use within your monitor calibration software. You can set target black and white points in the software before you calibrate, then adjust the monitor to those points, using the software. Once that is done, the monitor profile is created from RGB color ramps and a gray ramp.
Another key is to use ambient lighting or a light box to illuminate your prints to a level that is close to the monitor brightness, and to use a target white point of 6500K on the monitor and 5000K at 93+ CRI (color rendering index) in your print viewing area. (The explanation for this disparity is VERY long-winded and technical, but trust me, it works. I set up a large photo lab that way.)
Another key is to use ambient lighting or a light box to illuminate your prints to a level that is close to the monitor brightness, and to use a target white point of 6500K on the monitor and 5000K at 93+ CRI (color rendering index) in your print viewing area. (The explanation for this disparity is VERY long-winded and technical, but trust me, it works. I set up a large photo lab that way.)
nikonwaddy wrote:
Thank you friend, and I mean that, if I knew what ... (show quote)
Jun 5, 2015 05:03:29 #
nikonwaddy wrote:
Thank you friend, and I mean that, if I knew what ... (show quote)
In the profiling software there is choice to make regarding white and black points. You can let the software choose these automatically or you can manually enter them. Auto generally works great for viewing, but will still be too bright for printing, and you will get dark prints.
The unit of value for this is candela per meter squared or - cda/m^2.
80 is the white point, .4 is the black point. If using 80 still gives you prints that are too dark, then try 77, 75, 73 etc until you get what you are looking for.
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