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p.1 #8 · p.1 #8 · Photoshop basics guide - color and profiles | |
If you open up a file ... any file, any space ... in PS, then go to the bottom of the list and find:
Edit>Assign Profile
Edit>Convert To Profile
For practice/education/reference ... take the file and using just Assign Profile ... change the profile from sRGB to aRGB to ProPhotoRGB to CIERGB to Apple RGB and back again to any of the RGB's of choice. What you'll find is that the numeric value of a given pixel doesn't change, but how the monitor (device) chooses to display that given pixels does, relative to color.
It's kinda like playing the game of "Mother, may I". You can ask to take 10 steps, but you have to specify baby steps vs.regular steps vs. giant steps. You assign the number of steps @ 0-255 and depending on how large of steps (sRGB vs. aRGB vs. ProPhotoRGB) you choose will determine "how far out there" your color goes. Take 10 sRGB steps and you don't go as far as taking 10 aRGB steps, as the steps are a bit closer together.
Another way of thinking about it is a yardstick vs. a meter. Go to the number 32 on each and you wind up in a different place, with 32 centimeters being not nearly as far as 32 inches. Conversely, go to the number 87 and you wind up off the chart, over the edge, out of gamut, i.e. too far for the yardstick.
After you play with the Assign Profile a while and get a feel for just how much the different profiles play with a different size stick @ 0-255, then move on to playing with Convert Profile.
You'll find that you can use Convert Profile to interchangeable move from one color space to another without having radically significant changes. This is not to suggest that there aren't some issues @ clipping in certain situations, but to hopefully help you realize that you can move into and out of color spaces such that you aren't making a life changing decision by working in one color space vs. the other. BTW, before the bashing begins ... yes, it is preferable to not be converting back and forth for optimal output, but this is for the primary purpose of understanding the differences, not establishing the most technically ideal workflow.
Personally, I shoot RAW + jpg, so when I open RAW I'm in the ProPhoto Color space and when I open my jpg's I'm in sRGB. Whether I process from the ProPhoto or sRGB doesn't change the way I process my image in PS ... I still process the colors to where I want them. I just make sure to convert to sRGB for web usage prior to saving that which I'm going to post online (i.e. sRGB world) ... or to the profile that a printer may use.
Sometimes, I'll take an sRGB and assign it to aRGB and my colors change to the larger color space (baby steps to regular steps) and they get "out there" a little farther, then I might pull them back just a touch via desat. Sometimes I find this preferable than pushing them in sRGB.
The point here is this ... 0-255 are the notes that we get to play with. Pick up a violin and play the scale, it has one sound... play the same scale on a viola or cello and you get a different sound. Using a different color space is like using a different instrument to play the scale. The farther from "middle C" you go, the more salient the difference in size of the instrument makes to render a different sound.
This isn't meant to tell you how you should approach your color space, but to hopefully give you a better understanding of the differences regarding color space, so that you don't feel it to be such a daunting/overwhelming issue. Kinda like the exercise of lighting a sphere, pyramid and cube ... it is to help develop an understanding ... then you can make you own determinations @ application according to your preferences.
So to coincide with Peter ... for now, grab a violin and start playing the fiddle. If you find that you need a viola or cello, you can always change to that later.
HTH, GL
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