What's the Difference between sRGB and Adobe RGB..?

Johnny V wrote in post #14215017
Someone doesn't understand something and it's not me.

How many colours can a 16 bit aRGB image contain?

How many colours can a 16 bit sRGB image contain?

Thanks for this Hollis! You beat me to the punch. When i think of sRGB I think in 8 bit jpeg only... when I think of Adobe RGB atnd ProPhoto RGB colorspace I think in 16 bit. I've been shooting so long using 16 Bit RAW, TIF and PSD that sRGB is regulated to 8 bit jpegs for web display.

Johnny V wrote in post #14217160
The below color plots clearly shows the sRGB colorspace doesn't even cover images printed on the lowly 2200 Matt Paper...you'll need to move up to Adobe at least and even that colorspace gets clipped.

Johnny V is right on this one - see plots from my R1900 below.

But, Johnny, your advice, " shoot using Adobe RGB you can always save a sRGB when needed," isn't good advice for a jpg shooter. Because of the lower color resolution (the gaps between adjacent tones) of Adobe RGB you will end up with fewer colors if the workflow is Raw data>Adobe RGB>sRGB than if it is Raw>sRGB. If you have access to an application with a color counter, do a simple experiment. Generate from Raw an sRGB image and the same image in Adobe RGB. Convert the Adobe RGB to sRGB and compare the numbers. I just did it with a portrait against a black background, so I knew all the subject colors are within sRGB. The numbers were 131,000 in the 'from Raw' sRGB and 91,000 in the 'from Adobe RGB' sRGB.

>But, Johnny, your advise, " shoot using Adobe RGB you can always save a sRGB when needed," isn't good advise for a jpg shooter. Because of the lower color resolution (the gaps between adjacent tones) of Adobe RGB you will end up with fewer colors if the workflow is Raw data>Adobe RGB>sRGB than if it is Raw>sRGB.

Cool! Didn't know about the color loss from Adobe RGB jpeg to sRGB jpeg. That's why I shoot in RAW and keep my files in 16-bit as long as possible.

Johnny V wrote in post #14219097
>But, Johnny, your advise, " shoot using Adobe RGB you can always save a sRGB when needed," isn't good advise for a jpg shooter. Because of the lower color resolution (the gaps between adjacent tones) of Adobe RGB you will end up with fewer colors if the workflow is Raw data>Adobe RGB>sRGB than if it is Raw>sRGB.

Cool! Didn't know about the color loss from Adobe RGB jpeg to sRGB jpeg. That's why I shoot in RAW and keep my files in 16-bit as long as possible.

I'd never heard that before either; luckily, my workflow is the same as yours.

hollis_f wrote in post #14218725
How many colours can a 16 bit aRGB image contain?

How many colours can a 16 bit sRGB image contain?

The same exact # of colors.

if you convert aRGB to sRGB then back to aRGB, will you loss all the original aRGB colors info?

I was thinking of using aRGB the whole time in all software and my camera until printing and/or posting in the net. Does that sounds right?

P.S.: I'm shooting Raw

vinmunoz wrote in post #14730442
if you convert aRGB to sRGB then back to aRGB, will you loss all the original aRGB colors info?

I was thinking of using aRGB the whole time in all software and my camera until printing and/or posting in the net. Does that sounds right?

P.S.: I'm shooting Raw

I use this analogy because folks can more easily comprehend counting and conversion between number systems...

• Number system 1: I can count 1000 values, from 0 to 999, in increments of one
  
• Number system 2: I can count 1000 values, from 0 to 1998, in increments of two

If you shoot Raw, save only the Raw + its editing (LR catalog, ACR .xmp file, DPP edits saved in the CR2). If you need a sRGB jpg, make one, use it and delete it. If you need another, it is a matter of seconds to make another. If you need an Adobe RGB file, convert/export one when you need it. But the Raw shooter rarely needs an Adobe RGB file. The most common use for one would be if you have an inkjet printer that supports the Adobe RGB gamut, but because many printers at that quality level actually have a print gamut larger than Adobe RGB, you would be better off printing directly from the Raw instead of reducing it to the gamut of Adobe RGB prior to printing.

Of course, some day Vogue or The National Geographic might give you a call and they prefer Adobe RGB, but they will probably be willing to wait a minute while you export it from the Raw.