cbtsam Loc: Monkton, MD

I'm not at all expert in this area, but I've read that I should do my work in Photoshop using the Prophoto color space, rather than Adobe RGB, since its just about the biggest color space. Then I learned that I should downsize my color space to sRGB for most internet applications, even though sRGB is even smaller than Adobe RGB. So, having done a lot of post-secondary education, I've learned to follow directions, and I use Prophoto in Photoshop, and convert to sRGB for the net. Now I've been told that printers' output uses an even smaller colorspace than sRGB, which rather surprised me.

Now my question: if I've got to use sRGB to publish on the net, and an even smaller color space to make prints or books, why in the world do I need Prophoto, or even Adobe RGB, in Photoshop? If the output is inevitably going to be shrunk to a tinier 8 bit color space, why not just start out there? I imagine there is a reason, but I'd appreciate some education here. And thanks in advance.

Longshadow Loc: Audubon, PA, United States

Be interesting to find out, information wise.
sRGB is most prevalent, so I use sRGB and send that to my printer - I have no idea what the printer does with the data. I'm not concerned with other color spaces.

Ysarex Loc: St. Louis

You're not getting good information there. The ProPhoto, Adobe RGB and sRGB color spaces are device independent color spaces. A printer's color space is device dependent -- unique to that specific printer. Printer color spaces are limited by the inks they use and there's lots of different kinds of printers using lots of different inks. What we end up with then when we go to compare printer device dependent color spaces with the device independent color spaces is mismatches in some colors and not in others. For example X brand/model printer may have inks capable of creating greens that aren't in the sRBG color space while at the same time lacking inks to create magentas and reds that are in the sRGB color space. We don't have perfect matches such that a specific printer is sRGB capable or Adobe RGB capable -- we have to look at each printer brand/model specifically to see what it's capable of producing.

While you're editing an image in PS you may make changes to the tone/color of the image. You want to do that in the least restrictive working space (ProPhoto) to avoid creating problems early on. Think of it as banging up against the wall inside of a container. You want lots of room at first which the ProPhoto container gives you so you won't bang into the sides of the container as you work. When you have the image looking the way you want it then you start the process of reduction to a smaller color space and see how well the image handles that.

Strodav Loc: Houston, Tx

I understand device independent color spaces. From a practical standpoint, I don’t quite agree that pro photo, Adobe RGB, and srgb are device independent unless you are looking at your images in hexidecimal or doing mathematical transformations between color spaces. You are looking at them on a monitor so you are seeing your image mapped in to the monitor’s color space, calibrated or not. Common modern monitors can all achieve the srgb color space, and many can manage Adobe rgb (my Dell 27” monitor covers 99% of the Adobe rgb color space). I set my camera bodies to output Adobe rgb, which impacts jpg images, raw images are converted to things like pro photo in PS or LRc based on Adobe’s a-priori knowledge of the camera’s filters and sensor.

My philosophy is to shoot raw, largest color space my cameras can achieve, keep my monitor calibrated to Adobe rgb, convert to the color space of the output device. If larger color space output devices show up in the future, I’ll have the data to feed them. So, right now, for social media, it’s output to srgb. I build profiles for the papers I use with my Epson printer. I even built profiles for commercial printers that I use like printing on glass with Fracture or on canvas with mpix.com, which are supposed to be srgb, but not quite. The real magic is in how to map colors in the larger color spaces that cannot be reproduced in more limited color spaces to colors that can be reproduced in the more limited color spaces. In any case, 99.9% of photography is based on pleasing color or memory colors. Not color matching.

Ysarex Loc: St. Louis

A monitor has it's own device dependent color space. For us to see any color while working in photography a device dependent medium is required. So given what you're saying none of us can ever actually see a color that is from a device independent color space. Right?

Because ProPhoto, sRGB and Adobe RGB are subsets of CIE Lab (the ultimate device independent color space which can never be seen?) and were designed to address specific requirements, some folks like to distinguish them by calling them working spaces. I prefer a simpler less complicated definition. A color space is either attached to a specific hardware device, monitor, printer, scanner, sensor, etc., or it's not. Attached to a hardware device the color space is device dependent -- it's the color space of that device. Not attached to any hardware device makes the color space device independent and ProPhoto, sRGB, and Adobe RGB exist unattached to any specific hardware device. I don't see being attached to a "requirement" the same thing as being attached to a printer. An sRGB photo can be viewed and that same sRGB photo can be printed and that same sRGB photo came from a camera.

To view an image in which the colors are defined by the sRGB color space a device with it's own device dependent color space must always be used. Assume the same image's colors are defined by the CIE Lab color space. To view that image a device with it's own device dependent color space must always be used. What's the difference?

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

Good question. Great answers below.

https://photographylife.com/srgb-vs-adobe-rgb-vs-prophoto-rgb#:~:text=There's%20a%20reason%20why%20Lightroom,risk%20of%20clipping%20colors%20unnecessarily.
https://martinbaileyphotography.com/2014/05/27/why-use-the-prophoto-rgb-color-space-podcast-423/
https://fstoppers.com/education/srgb-adobe-rgb-prophoto-rgb-which-use-and-why-316223
https://petapixel.com/2018/12/13/srgb-vs-adobe-rgb-vs-prophoto-rgb-color-spaces-explained/
https://community.adobe.com/t5/photoshop-ecosystem-discussions/srgb-vs-prophoto/m-p/8524426
https://www.youtube.com/watch?v=ujE5bBXIKJE
https://www.youtube.com/watch?v=g3Y6RQC0YRA
https://www.lightroomqueen.com/color-space-use/

Longshadow Loc: Audubon, PA, United States

Don'tcha hate it when you can't get all of the angstroms out of a color.

camerapapi Loc: Miami, Fl.

Color spaces are not that simple to understand. We all know that sRGB is what the majority of the printers use, what our monitors can see and what all editing softwares process. It does not matter if we use ProPhoto, Adobe RGB or sRGB, our monitors or our eyes cannot see all the colors.
One good reason to use wide color spaces, as I see it, is that we can work with 16 bits of information. Editing with 8 bits, like using JPEG files is not the best for the information contained in the file. For sure some color shifts will occur and banding has an excellent chance to be present. Do we need ProPhoto? That is an interesting question. Nobody here can tell the difference between Adobe RGB and ProPhoto in a RAW data although it is known the latter has a wider color space. Let me repeat it, we do not see all the colors.

When Adobe RGB and ProPhoto are converted to sRGB, which we all know is a smaller color space most of the color information of the original is lost but still our eyes cannot see it. Manipulating the larger color spaces while editing RAW data allows to keep the information but a JPEG file with the sRGB color space is a lossy compression which means data will be lost the more the image is manipulated. A JPEG file is alright BUT the less the file is manipulated the better.

I am not familiar with printers but I can understand they all use different inks. I have no profiles for my images and Costco has been my main print supplier since I do not print at home. I only once had a mismatch at Costco between my file and their print but otherwise I have always been very satisfied with the quality of their color prints. I know the majority of Epson printers can see and reproduce Adobe RGB and sRGB. There is no printer bureau in this country, that I know of, that will accept ProPhoto or Adobe RGB and NONE will accept an image in RAW data. It has to be JPEG and the sRGB color space. Let me emphasize it once again, while editing RAW data my recommendation is to use Adobe RGB or ProPhoto and when ready to print to convert to JPEG and the sRGB color space.

I am not an expert in color spaces and my eyes are not the same as they were 20 years ago. I have been into digital for more than 15 yeas and still there are many things I do not understand. Something I do understand is that I do not see a difference between the colors of ProPhoto, Adobe RGB and sRGB color spaces. I can understand that using 16 bits of information while manipulating images in an editor is far better than going 8 bits.

The information supplied by Gene 51 is most useful to understand the differences. If something you need to learn is that editing in 16 bits of information is the best assurance that neither color shifts or banding will occur. When it comes to color, we cannot see them all and that includes sRGB.
I hope this helps.

Longshadow Loc: Audubon, PA, United States

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

In a gross oversimplification -boxes of crayons come in sets of 8 colors and go up to as many as 200 (Crayola). Why 200? well with the 8 pack you almost get the rainbow - red, orange, yellow, green, blue, violet - then brown and black. Is that enough to create a full color image? No. The larger color sets provide all sorts of nuanced color and tone that would be difficult if not impossible to do with 8 crayons.

So, the reality is that a large number of art can be done with a relatively small palette of colors. Is it necessary to use all 200 colors in the large set to make an image? The majority of the time no.

Working with an 8 bit jpeg in sRGB color space is sort of analogous to the small box of crayons. If you look at most images, they neither have all the colors nor all the tones. This is true regardless of whether you recorded the image as a raw file with an infinite number colors and tones, or you chose to let the camera process that file into an 8 bit sRGB output image.

So the question is are you better off starting with the big palette, editing to your pleasure, then reducing the color and tone set to only those used, or starting out with a reduced color set (sRGB) and risk getting tones and colors during editing that are beyond the smaller number of colors and tones - and end up with out of gamut errors and banding on subtle transitions.

You can certainly edit jpegs, but when you get beyond simple and narrowly ranged adjustments the image starts to come apart.

Here's an example of what can be done with a full set of color crayons, like

https://www.art-is-fun.com/crayon-art

Longshadow Loc: Audubon, PA, United States

Only the photographer knows for sure.

Other viewers? That's a different story.
(They won't worry about, or be concerned with, what color space was used.)

lamiaceae Loc: San Luis Obispo County, CA

You don't need it. You probably can not view it either on most monitors. You might see some difference on a super high end print.

photoman43

My color space rules are real simple:

Shoot in RAW with the largest color space available, usually Adobe RGB.
Process in the largest colorspace available, usually Pro Photo RGB or Adobe RGB.
Jpegs for the Internet--no change in colorspace. I never change to sRBG.
Images for printers and prints --use exactly the specs they ask for: Jpeg or Tiff, bit depth, color space, etc. But the output image for the printer is made from the RAW image processed in ProphotoRGB or adobe RGB.

burkphoto Loc: High Point, NC

Using ProPhoto RGB is all about preserving maximum data while you are working on images. When you convert a raw data file from the camera initially, whatever color space you are using LIMITS the color gamut to ITS limits. If you're using a super-wide gamut like ProPhoto RGB as your "working color space," you are preserving as much of the captured information as possible. You can adjust it in reference to another color space by using the "soft proofing" or "output simulation" feature of your software. That way, you can see (as best your hardware-calibrated and profiled monitor can display it) what you are going to see in print or on the Internet on calibrated devices, and make final adjustments accordingly.

Four-color offset and gravure printers use the CMYK color model, which prints with Cyan, Magenta, Yellow, and black (K=Key color). Because only four inks are used, the process uses semi transparent inks and varies dot spacing to remove color reflected off the (ideally) white paper. That's why we call CMY the three subtractive primaries. Black (typically the Key color) is added to improve contrast. The subtractive model is limited by the use of three inks and the reliance on reflected light. The limit is a narrower color gamut.

Photo quality inkjet printers enlarge the color gamut by using more colors of ink. 6, 8, 10, and 12 color models are often used for color-accurate inkjet photo printing. The best Canon and Epson inkjet printers can reproduce Adobe RGB pretty faithfully. The four color models are close to sRGB.

Commercial offset printers, magazine editors, and advertising agencies often tell customers and photographers to supply images in Adobe RGB, because they may need to adjust them to their own conditions. They simply want as much color gamut as possible, so they lose less when converting to their own tastes and/or press conditions. Their 25-year-old assumption that MOST people do not understand color management, and do not use calibrated and profiled monitors, is less often correct these days. In the late 1990s through about 2010, they received a lot of digital excrement that did not meet their standards. While that is still a problem, it is less of one in 2021.

It's like the old "300 dpi" rule. Most printers don't need "300 dpi at reproduction size," except when they change a layout and enlarge an image slightly to fit it. Most printing presses can't resolve more than around 200 dpi (I confirmed this in 1998 press tests at a yearbook and school portrait company I worked for then). They just want the "editorial fudge factor" that 300 dpi provides.

These little trade practices tend to come out at trade shows and their seminars...

The Watcher

Here's one of the best color spaces videos that I've seen.

https://www.youtube.com/watch?v=071XzduxEqI