Longshadow wrote:
Interesting, RGB pro, as well as ProPhotoRGB, are new to me.
(I just send sRGB to Costco....)
Your camera has its own profile. When you process a JPEG IN THE CAMERA, the camera saves the file to whatever you can choose in your menu (usually either sRGB, or Adobe RGB).
When you save a raw data file in the camera, your post-processing software has to apply a profile to it when you open it. Opening a file creates a bitmap image in memory. The software or OS then converts the image from that camera profile to your working space or connection space profile. From the working space, it converts the bitmap image to your monitor profile, so you can see it. When you export or save a file, you can choose to convert it to a specific profile. Commonly:
> sRGB is used as the standard for Internet images.
> sRGB is accepted as the default by nearly all silver-halide based photo labs (those who print on traditional, wet-process, light sensitive photo papers).
> Adobe RGB is an option at SOME photo labs (usually pro labs). It has a bit wider gamut (can reproduce more saturated colors) than sRGB. Whether much of that gamut can be reproduced on photo paper is up to the combination of photo paper and printer used by the lab.
> Adobe RGB is an option at SOME offset litho printers and gravure print houses, and may be a requirement at others. They usually want this profile because they don't trust photographers to use calibrated monitors or to know much about color management or offset printing systems, so they want the slight edge in latitude that Adobe RGB provides for adjustment to their paper and press conditions. Their dirty little secret?* They print color separations using CMYK (cyan, magenta, yellow, and black inks), a process which has an even more limited color gamut than sRGB.
(*How do I know this? As a former member of DIMA and PMAI (Digital Imaging Marketing Association and Photo Marketing Association International, now defunct trade groups that merged into PMA@CES and others), I heard industry experts explain it at trade show panel discussions and training sessions. I also worked for a yearbook printer and pro photo lab, where I saw it in action.)
> ProPhoto RGB, ROMM RGB, and Melissa RGB, are all extremely wide color gamuts that are primarily useful for preserving maximum data in 16-bit images shared between or among post-processing applications. For instance, when I send a file from Lightroom Classic to Photoshop CC 2019, I use ProPhoto RGB. The only time it gets converted to something else is when I export the file from Lightroom, or possibly save the file from Photoshop, or print it to a locally connected printer.
> Very advanced photographers, ad agencies, and fine art museums use a "closed loop" printing system of sorts. They:
> Convert the raw file from the camera to its camera color space (in something like Lightroom).
> Manipulate the file entirely in ProPhoto RGB or similar (possibly in several different applications).
> Print to a high-end inkjet photo printer, doing the conversion from 16-bit ProPhoto RGB to a 16-bit printer driver, and applying the printer/paper/ink device profile "on the fly" at time of printing. This preserves the maximum possible printed color gamut from point of click (photography) to point off clunk (the print landing in the receiving basket under the wide format printer).
MOST people are best off saving or exporting images in sRGB, most of the time. It takes a really good, wide-gamut monitor and a 10-bit graphics card, plus a hardware/software color calibration kit and a lot of discipline, to reap the benefits of a system for Adobe RGB image processing, evaluation, and usage.
Folks, if you want to make a real difference in the quality of your work, calibrate your monitor with a hardware device (colorimeter or spectrophotometer) and custom profile it with a hardware/software kit from Datacolor or X-Rite). If your monitor doesn't display accurate color, none of the benefits of color management or color adjustment are certain. You have to SEE what's in your files to manipulate it predictably.