Board index Photography Technical Questions Adobe RGB (1998) vs. sRGB

Technical Questions

Adobe RGB (1998) vs. sRGB

Discuss technical aspects of photography
marxz
 
Posts: 282


Post Thu Jun 14, 2007 11:15 am


I'm lucky enough to have two identical monitors (by lucky I mean I already had a 20" Apple studio display and when I purchased a second hand G5 tower it, unknown to me until I picked it up, came with an identical monitor)

After noticing the extreme differences between what I was seeing on my computer and when viewing my pbase images on friends and coworkers computers I remembered that web browsers uses sRGB (and of course none of these people calibrate their monitors).

So just in the last few days I've changed my setup - I work on one colour calibrated monitor as my primary work space but I changed the second monitor's colour profile off of its colour calibrated setting and back to sRGB.

Now after working on an image I'll saved it with the calibrated profile (but keep it open), open a copy of that image, change it's profile to sRGB and drag it on to the sRGB profiled monitor then use a hue/saturation and curves adjustment layers to get it to match as closely as possible the image I'm seeing on my calibrated monitor. To my amateur eyes I can get a reasonable, though not exact, aproximation.



Not the most scientific approach I guess and I'm sure some here can either laugh at that and/or offer a more systematic/scientific approach
... but then I'm trying to get away from my old "image as a record of fact" ways towards a more "image as a reflection of an experience" so I might just ignore you and carry on my merry little way :P

madlights
 
Posts: 912


Post Sat Jun 16, 2007 5:30 am


I tried something similar...though not exactly. I've got 2 PC's networked on one monitor and a KVM switch. So one of the computers is set up with ARGB (or sometimes to Prophoto) and the other to srgb...and the one in srgb isn't calibrated as well...so i flop them back and forth...and when trying to establish a look on the srgb one just kind of sometimes "well that's close enough" since knowing 90% of the people who look, if you asked them if they 'calibrated their monitors' would look very strangely at the person asking.

crisscross
 
Posts: 70

Re: Adobe RGB (1998) vs. sRGB

Post Wed Sep 03, 2008 11:57 am


I would like to re-open this discussion. I use the Nikon version of Adobe 1998 RGB in the camera (D80), for calibrated screen (MacBook pro)....and posting.

I know that it is safer to post after downgrading to sRGB, but I totally disagree about the quality of the result. Viewing uploads on an old PC (dell dimension 2400) it makes relatively little difference whether using Safari, which has built in Colour Profile recognition and display, or Firefox 2...but I would say that is because both are crude anyway.

Firefox 3 has an add-on 'Color management 0.4' which brings it parallel to Safari. I normally use FF3 with the add-on as it also has various other advantages beyond photography, but just for example fine-tunable ad removal, and it downloads pdf to chosen folder to use in ones preferred and preferenced viewer instead of opening an untuned reader within its own window.

So how long do we have to suffer the roughish sRGB environment before colour profiling becomes standard for all browsers including the one I don't mention??

If you have time, I would also be grateful for some feedback on how lousy my gallery images are compared to if you drag them off and open in decent graphics package. If needed can one do a mass-strip (of colour profile) on existing pBase galleries????

PS hadn't noticed marxz post on p2 - confirms the sort of tiresome procedure one needs to get the best of both worlds. Thanxz marxz

Chris (Herefordshire UK)

benjikan
 
Posts: 344

Re: Adobe RGB (1998) vs. sRGB

Post Sat Sep 20, 2008 10:06 pm


You should really calibrate your screen and use the profile of your screen as your barometer. This is how I am able to keep the chain accurate. In Photoshop you define the profile in your color preferences. The profile of your screen will come up in the color profile choices available. Just click on your screen profile and save.

If you need to send the image out to a lab you can include your calibrated screen profile that can be used to reproduce your image as you saw it.

Ben :)

ndigi
 
Posts: 5

Re: Adobe RGB (1998) vs. sRGB

Post Sat Oct 25, 2008 3:34 am


I agree with madlights that we should set our monitor, printer and camera to Adobe RGB profile. I am a novice in digital imaging. But I have something here to add, correct me if I am wrong.
I think a good quality grafic card palys an important role in geting a true to life colors so does a good quality monitor.

However, I am still baffled as to how to convert RGB to sRGB in Photoshop. Any gurus out there to enlighten me? For your information, I use CS2 most of the time although I have CS3.

Thanks.

dougj
 
Posts: 2276

Re: Adobe RGB (1998) vs. sRGB

Post Sat Oct 25, 2008 6:50 am


A mid-price graphic is all that's needed for good image processing, the high-end cards are required for high speed processing for gamming, 3-D graphics and the like. I use a NVIDIA 8600 GTS which is enough, maybe a little overkill.

A good monitor is important, and it should be calibrated. If you have a good eye, and good test graphic images you might be able to get the calibration close enough for your needs, this is a personal choice. Some photogs use what's called a spyder for calibration, this is basically a small optical device that temporarily fits on the screen while software displays various colors at different levels of brightness or intensity. The software measures the monitor output and when completed, it generates a profile specific for the monitor which loads automatically when the computer is booted. You generate a new profile periodically since monitor colors and brightness may change with age, this was needed more with the CRT type of monitors.

To convert and assign color profiles to a photo in CS3, first open the photo then:
> Edit > Show All Menu Items > Convert to Profile xxxxx.
> Edit > Show All Menu Items > Assign Profile xxxxx.
Save

You have to do both or the photo will be in one color space but it will tell all other programs that it is in a different one and it will not display properly.

While you're at it, you should also check the working color space for PS. Follow the same steps as above and then select Color Settings. The working color space for PS should be the same as the one you're using for the photo you're editing.

I hope this helps.

paulsilkphotography
 
Posts: 70

Re: Adobe RGB (1998) vs. sRGB

Post Sat Oct 25, 2008 1:25 pm


dougj wrote:You have to do both or the photo will be in one color space but it will tell all other programs that it is in a different one and it will not display properly.


While most of dougj's advise is sound this is not strictly correct, there is no need at all to assign a profile unless the image does not have a embeded color profile (which is rare) ,and if you have the profile mismatch warning ticked in your color setting as you should you will get a warning that the image has no profile and can then assign one. If a profile is present that is different to your working space you will just be asked to either use the embeded profile (in which case the image will be displayed in that profiles color space) or convert the profile to the working space

You only need to convert to profile (using s-rgb for the web) unless the above applies. If you assign a s-rgb profile to a image that has a Adobe rgb profile the image will desaturate in colour which is not what you want.

Also when converting the colour space of a image for the web I advise you do it to a copy.
Keep on snapping and catch the moment if you can.
Paul

http://www.pbase.com/paulsilkphotography

dougj
 
Posts: 2276

Re: Adobe RGB (1998) vs. sRGB

Post Sat Oct 25, 2008 7:04 pm


Paul is correct in that assigning a profile is only rarely needed. If the photo has the color space information saved as part of the metadata when it was created, or converted this is enough for another program to identify the color space. When converting any color space, not just for use on the web, it is best to save the converted image as a copy.

madlights
 
Posts: 912

Re: Adobe RGB (1998) vs. sRGB

Post Tue Nov 17, 2009 11:03 pm


I know this is an old topic, but something about it has bothered me, since I've monkeyed around with this some. Now Adobe RGB isn't spread out all over the place, it's wide but...Prophophoto is a lot wider. Maybe someone knows a lot more of this than myself, so this is to get a discussion going. It's kind of like a fish net, in a confined space. The confined space is what the picture is and how it can be displayed, the net is the color space. What the net catches is defined by which color space is applied to the picture. SRGB catches not so much but the net is more closely woven and catches smaller fish. ARGB a lttle looser weave, but catches more maybe like bass? And Prophoto catches the widest range of colors but maybe only big fish like sharks, but the gaps in the net become a lot wider? Of what benefit would shooting black and white in any other color space than srgb be? or if you shoot color in 8bit jpg. would it benefit a person to use a wide color space when the bits to define color are strained more anyway compared to a 16bit file? I've found "sometimes" less posterizing when darkening skies etc. in srgb than even in argb in RAW files. Can we believe all we are told? I don't know I'm just asking opinions on this. Much equipment is designed to display less gamut than say Prophoto can show. Of what benefit are we to use wider color spaces? unless we're doing infrared or ultraviolet photography or want to catch certain colors (but we'd better know which ones). I realize that srgb is a supposedly lowly web standard, but aren't there trade offs for even printing applications and ones own monitor display when using wider spaces? I do realize that 'some' colors display and print better in Adobe rgb (I've found Prophoto problematic with some colors, may be my monitors - and haven't tried to print in it), but isn't there trade offs for anything you get in a confined space? Just wondering what anyone else thinks about this. To further complicate, maybe it's a matter of using the best color space for the photo, rather than any dogmatic approach?

sean_mcr
 
Posts: 493

Re: Adobe RGB (1998) vs. sRGB

Post Wed Nov 18, 2009 11:44 am


Barri,

There's no point working in the prophoto colour space if you've shot in Jpeg as the colours have already been compressed, you can't bring back information that's no longer there. I know you often work with Jpegs Barri, so don't bother with prophoto if that's what your're working with, there's simply no point. Working with ProphotoRGB v RGB is kinda like 8 bit v 16 bit, you've simply got more information to work with. What's the one thing that those of us that shot with black and white film, miss? Latitude; That's the main argument against digital black and white. Nobody ever complained that they had too much latitude when shooting with black and white film. My printer (and others) with certain papers can produce colours that are beyond AdobeRGB let alone srgb. I'm not trying to create scifi colours, I'm trying to avoid issues like gamut clipping. I've got to say to that there is no way that a 16 bit file's more likely to lead to banding/ posterizing than 8bit file is, as banding/ posterizing is due to a loss of digital information which is far more likely to occur when editing in 8bit mode then it is in 16 bit.

A poor monitor is often the cause for visibly poor transitions of tone, you've got to have a monitor that's up to the job. If you're sat there under a tungsten energy saving bulb trying to calibrate a poor monitor by sight, then you might as well carry on doing what you're doing, pal. You're never going to be able to trust that what you're seeing on your screen is accurate, so I'd not worry about it. But if you really want to make prints to the best of your ability, then Barri, there's a limit to what you can learn on a forum, you really should consider getting Bruce Fraser's real world colour management and something like a video tutorial such as Luminous landscapes "From Camera To Print" which will go a long way to helping you understand the issues involved, consider attending one of Epson's print academies. that will allow you to make an informed choice, you can't work with something unless you fully understand it. If it's a question of belief, it's got to be based on knowledge.

My shots are now off pbase, I'm out of here. But if I sent you one of my shots now, I know you'd not be seeing what I'm seeing. It's no good me sat here with D50 lighting, an Eizo hardware calibrated (not the same thing as sofware calibrated) monitor thinking that people online are going to see my images as I do. Too many variables, too much poor colour management. In truth it's prints that I'm interested in, not low res files on the net. If Photographs are an impression of the world then web images are mere impressions of photographs and most often poor ones. If you're going to make good prints which is a craft in itself, then you're going to need to fully get grips with colour management. I've just bought a portable D50 and 3500k lamp so people can view my prints in the right light. If I take my prints to somebody, I'll take the light with me.


It all really boils down to how much you care about it. It's not a secret known only to members of the magic circle, you just can't guess your way through it, you've got to learn it fully and you wont do that on a forum.

This is my last post on Pbase so forgive me If I don't reply;

I'm off to print some photographs

Take it easy

Sean
What uses having a great depth of field, if there is not an adequate depth of feeling? -

W. Eugene Smith

madlights
 
Posts: 912

Re: Adobe RGB (1998) vs. sRGB

Post Wed Nov 18, 2009 1:42 pm


Hey Sean...
Total re-edit. Well I set it up like you told me. Then I tried to get it to band by darkening large flat areas. And I could get no banding. I did get some posterizing, but it was only noise from my camera which made an unevenness when darkened that much. Worked fine. Worst of all you were right :wink: so I've got to admit it. :lol: Think what I'd been reading is from people who didn't set it up correctly. Thanks much, I'll be doing much more in that color space now...I've always liked the greens and blues it has.

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