Color Space

[Sleeping Bear]

Okay, I've got a RAW file shot with the S2 being converted in Photoshop CS. What color space should I be using? Adobe RGB? I know the S2's Color Profile is not Adobe RGB. Can someone walk this poor, lost, color spaceless soul through the proper workflow that will result in the most dynamic print possible when printing at a lab using Fuji equpiment? A lab such as Linda G's. Linda! Help! I know you have said many times that it depends on the lab, Linda. What is your workflow for having prints made in your lab? I really appreciate any help, gang. And if there is already a thread with this info, my apologies and please point my pointy head in the right direction. :)

[Linda G]

Hello!

We just returned from Quivira wildlife refuge and were skunked...no birds or wildlife in sight! Signs everywhere exclaimed nesting whooping cranes but that's the only 'sign' of them!

As for color spaces, if you are printing, Srgb is what you want. I think there are two obscure printers that use Adobe rgb.

If you have your image in adobe rgb and send it to a printer that uses srgb (the majority of printers), it will be automatically converted to srgb and the results are then unpredictable.

Adobe RGB is a much bigger color space. What does that mean? Well, I'll try to do a graphic later. For now, think of adobe rgb for web use only. I'll work on the graphic to include in the next post, for now, just use Srgb. K?

[Linda G]

http://www.shootsmarter.com/infocenter/wc025.html

Better than my explanation or a graphic I could have drawn.

[Sleeping Bear]

When I was reading the first sentence in your post I thought you were really skunked, pew! Better to be skunked with photos than skunked with skunk. :lol: Thanks for the quick tip.

[Sleeping Bear]

Thanks for the link, Linda. I'll check it out.

[AzRich]

Sorry to hear about that.. reminds me of my recent outing to Zion.

Thanx for the link, VERY helpful.

[Sleeping Bear]

Okay, now that I've blundered and set my working color space to Adobe RGB, thus changing the profile of my RAW shots, will I harm them by changing the profile back to the Srgb Photoshop CS uses? This conversion should be done before I make any adjustments to the RAW shot, correct? I hope I have not killed my shots. :eek: First they have an embedded profile of Srgb, then Adobe RGE, now we go back to Srgb. Whos' on first?

[sandman]

Same subject but a different question , Rons question and Lindas link have made me remember a question i have .
What colour space should i set C.S to , i have every thing incuding my D70 set to sRGB , but is this the way C.S should be set up to get both optimum images from both printer and web .
I remember there was an old thread on this from Ian Mc i think .

Brian

[Linda G]

Ron,

You have three choices, all will leave you with Srgb files for printing.

1. reconvert your images from raw using srgb

2. leave the adobe rgb images as they are and send to print, getting questionable results as the machine prints it in rgb and it will convert it for you.

3. change your files now to srgb that you want printed and look at the results, making sure switching back and forth hasn't hurt the image noticeably

As the link I sent you explains, switching back and forth degrades the quality of the image but at what point you're going to be able to tell by looking at it is a guess. I'd say, take one file and do an experiment....convert that raw image using the srgb and compare it to the same image that was converted in adobe rgb that you have switched to srgb.

AAAHHH! I feel like I'm stuttering in rgb!

Then, print them out small to compare, too. make sure you know which is which when they come off the printer!

[Tom Nolle]

IMHO it's best to use Adobe RGB for your working color space and then convert for printing/viewing. The Adobe software handles the conversion effectively as long as you have a correct color profile for your monitor and output device. Larger color spaces seem to me to be more useful than smaller ones; you can map a large space to a small one (sRGB) for output with something like down-sampling, but to map a small space to a large one it would seem you'd have to interpolate. sRGB was actually invented for Windows/web applications, if I recall correctly.

Tom

[Melody]

Yep it's just yet another example of contacting who, where and what the print is for, as Linda has said many times.

Dye sublimation works much better with rgb. I prefer it for the canvas prints as well on the inkjets too, the sites I researched recommend that as well.

In other words if you don't know what all your going to be doing with those pictures save that raw file! :)


Melody

[Sleeping Bear]

Ron,

You have three choices, all will leave you with Srgb files for printing.

1. reconvert your images from raw using srgb

2. leave the adobe rgb images as they are and send to print, getting questionable results as the machine prints it in rgb and it will convert it for you.

3. change your files now to srgb that you want printed and look at the results, making sure switching back and forth hasn't hurt the image noticeably

As the link I sent you explains, switching back and forth degrades the quality of the image but at what point you're going to be able to tell by looking at it is a guess. I'd say, take one file and do an experiment....convert that raw image using the srgb and compare it to the same image that was converted in adobe rgb that you have switched to srgb.

AAAHHH! I feel like I'm stuttering in rgb!

Then, print them out small to compare, too. make sure you know which is which when they come off the printer!


I'm a little thick headed in this department, so bear with me. No pun intended. When you open the browser and open a file of RAW files with the working space in Photoshop CS as Adobe RGB, does it change the profile of the raw file? Or is this just the working space and the color profile of the raw file is whatever the camera is set at? Such as Srgb for the S2? I guess I'm wondering if you can alter the color profile of a raw file by changing the working space in CS. If you cannot then I won't even give it another thought.

Once you have a finished file in the form of a tiff, how would you convert the file to one color profile or another?

[Linda G]

Ron,

I'll have to research the conversion in pscs, I use the hyperutility because I'm not really happy with pscs conversions. When I que up EX converter, I have a choice of adobe or srgb.

I know you can change the profile in the image/mode dialog box as shown in the screen shot below.

When you convert in pscs, you have a choice at the bottom left of the screen to choose the color profile to use. That's the place you should choose when first converting. I believe, before that, the raw file cannot have a color space. There are four selections for a profile there, adobe, srgb, color match rgb and prophoto rgb. I know nothing about the other two, they must have specific uses but I don't know what.

This help?

[Linda G]

Ron, is your photoshop set up to have adobe rgb as the default color space? Here's a screen shot of my color preferences as found in edit/color settings

[Steve P]

Having read one of Scott Kelby's Photoshop manuals what ever you do you must change from sRGB iec61966-2.1 to RGB1998. He go's on to say that this iec61966 was devised some years back due to the poor quality of most monitors at that time and is not used in this day and age!

[Linda G]

Steve,

I do not see that as a choice in my photoshop program. Is it a profile you can download and add to it?

[Tom Nolle]

That's Adobe RGB, sometimes listed as "Adobe RGB 1998".

Tom

[Linda G]

Ah, well then. I guess that depends on whether you want your images to look good on the monitor or in the print.

Since Ron asked about printing, and equipment such as what I work with, the answer would again be the 1966 and not the 1998.

[Steve P]

Linda,

Go in to Colour Options in Photoshop and you'll see the default sRGB ie61966 selected. If you click on the drop box you will see Adobe1998. That's the one Scot recommends to use. When you open an older file you will probably have a pop up informing you of the change, again click ok!

[Linda G]

As stated before, that's great for monitors, not so for printing. It is sad that paper cannot capture the colors a light based monitor can but if you want to see what your images will look like printed, use 1966, if you are doing webbased only displays, 1998 is great.

[Tom Nolle]

Linda, are you sure that there's not something buggered in the color management? Adobe RGB has a much larger gamut than sRGB. All the color management books say that sRGB will lose something compared to the typical printer CMYK range.

Tom

[Melody]

Hi Tom, Steve,

You've got to remember she is talking about the lab she works for using a frontier? and photographic paper prints. Rightly so as that is what Ron asked about.

You are right Kelby, epson and many others do recommend the 1998 for printing, the color range is greater.

It just goes back to the type of print and the situation, I can't use the srgb with the dyesublimation the colors come out all wrong! I can use it with the canvas and the ultrachrome however the 1998 does come out better. Linda has said many times ask who is printing what they want or use, I very much agree.

Melody

[Linda G]

Tom,

There are three color spaces in discussion here, for three different purposes.

1. CMYK which is so personalized here it's not a good choice for uses other than what you know you'll need if working with a specific printer, usually newspapers, magazines and other press type printers. (probably others, too, but again, not for the type printing done by the majority of this group and definitely not what Ron is asking for)

2. Adobe RGB which is a great color space for web based use. Most printers will NOT have access to all the colors in the Adobe color space and will clip them when printed, leaving you with an image that does NOT look like what it does on your monitor.

3. SRGB a printing space with a smaller color space than Adobe's but with all the colors of the majority of printers. You will see what you will get when printed. This is what Ron is asking for. If he leaves his images in Adobe and sends to an RGB printer, the color space will be clipped and the printed images will look flatter than a.) what he sees on his screen and b.) what it would have printed had it been in the srgb color space when sent to the printer.

Does that make sense? Think of it this way:


Adobe RGB for web use


Srgb for printing

That is a basic call only, check with who is printing your stuff, they should know their equipment and what is needed to get the best prints. Then follow their advice or do your own experiments but if you don't trust your printer......find one you can.

[Tom Nolle]

Thanks, Linda. I guess it depends on how you get your stuff printed. I use Adobe RGB as my working space and it prints the same on my ALPS printer as sRGB does; I have an ALPS profile. For stuff I get printed, the printer usually asks me to convert the images I send to their printer profile (or pay extra). I know sRGB is a narrower gamut that was devised for the PC-style monitors and output devices, and I used that until I switched from the EX converter to PSCS this year. At that point I converted to Adobe RGB, and I still have some files in the older format. I took one file converted both ways and printed both images on the same sheet and I couldn't see a difference.

Ah, the mysteries of color management!

Tom

[HulaMike]

I guess my question would be, is there a fall off in image quality if you convert an aRGB file to sRGB for outsource printing?

At this point in time I print everything in house on Epson printers and use the Adobe RGB color space for file prep. That combined with an ICC printer profile for my printer/ink/paper combo gives me prints that match my on screen view exactly. But if I wanted to send this file to you Linda, and converted it to sRGB; would there be a noticeable fall off in saturation or quality???

[Linda G]

I guess my question would be, is there a fall off in image quality if you convert an aRGB file to sRGB for outsource printing?

At this point in time I print everything in house on Epson printers and use the Adobe RGB color space for file prep. That combined with an ICC printer profile for my printer/ink/paper combo gives me prints that match my on screen view exactly. But if I wanted to send this file to you Linda, and converted it to sRGB; would there be a noticeable fall off in saturation or quality???


Yes, Mike, that's what I've been trying to say. IF you leave it in Adobe RGB and print it on a Frontier, it may be okay but there will be times with certain colors, it will come out flat and muddy because the colors have been clipped by the smaller color space it's being printed in. Think of a histogram with the clipping going on there. The same thing happens when you print in a smaller space than your file is in.
It's best, if you are going to use your file to print, to start in sRGB but if you have it in Adobe rgb, it needs to be converted first so color corrections can be made for a good print.

We have had people send in files with Adobe and since we color correct every file, when it's printed out, we have a pretty good idea if it doesn't match what we see that it's in a different color space. We then have to start from scratch with the file, taking at least one extra day of in house time on that order to take them all into photoshop, convert them and reenter them into our system. Waste of paper, time and patience.

Now, don't get the idea that a Frontier, because of the smaller color space is less than desirable. I have never seen more brilliant pics than off this machine. Inkjets just can't compare, no matter what color space it prints from.

[Sleeping Bear]

Now, don't get the idea that a Frontier, because of the smaller color space is less than desirable. I have never seen more brilliant pics than off this machine. Inkjets just can't compare, no matter what color space it prints from.

I could not agree more. In the right hands a Fuji Frontier just can't be beat. That's why I'll be sending all of my stuff to Linda's lab. :) Esp for the larger prints since I could almost see Swampy drooling over his eagle prints from here. :lol:

[Linda G]

I could not agree more. In the right hands a Fuji Frontier just can't be beat. That's why I'll be sending all of my stuff to Linda's lab. :) Esp for the larger prints since I could almost see Swampy drooling over his eagle prints from here. :lol:


Which, thanks to Mel, are on their way!!!

[HulaMike]

Yes, Mike, that's what I've been trying to say. IF you leave it in Adobe RGB and print it on a Frontier, it may be okay but there will be times with certain colors, it will come out flat and muddy because the colors have been clipped by the smaller color space it's being printed in. Think of a histogram with the clipping going on there. The same thing happens when you print in a smaller space than your file is in.
It's best, if you are going to use your file to print, to start in sRGB but if you have it in Adobe rgb, it needs to be converted first so color corrections can be made for a good print.

We have had people send in files with Adobe and since we color correct every file, when it's printed out, we have a pretty good idea if it doesn't match what we see that it's in a different color space. We then have to start from scratch with the file, taking at least one extra day of in house time on that order to take them all into photoshop, convert them and reenter them into our system. Waste of paper, time and patience.

Now, don't get the idea that a Frontier, because of the smaller color space is less than desirable. I have never seen more brilliant pics than off this machine. Inkjets just can't compare, no matter what color space it prints from.

So to summarize, I open one of my aRGB files in PS viewing on a calibrated monitor, one that issues an exact view of the file as it will print in house on an Epson 1280. I then assign a sRGB profile to it. Is this how it will look when printed on Frontier assuming I'm viewing on the same calibrated monitor? If so, no big whoop here. I notice a small, but noticeable, fall off in color and strength but the file still looks pretty good. Have I got it correct now??

[Linda G]

Yes.

But of course, it's better to start with the color space you're going to end up printing with. You always lose something when doing any conversions.

[HulaMike]

hmmmm. Thanks Linda. Think I'll start a poll just for fun.

[Linda G]

A poll? for what? That may be interesting. Shall we title it:

Do you prepare your files as your printer suggests or for a different printer?

[Brad Harris]

I have been working with color management on my Mac and found this interesting. In the color sync utility you can compare color spaces so I took some screen shots of a Fuji S2 Generic profile overlapped with sRGB and Adobe RGB 1998. From these comparisons it looks like the Fuji S2 can capture a lot more color information than sRGB. So it would seem Adobe RGB is a better working space to work in to get the most color from the camera. Then if you need the sRGB color space use Photoshop's convert to profile. Samples Adobe RGB_Fuji S2(Shaded) sRGB_Fuji S2(Fuji Shaded) Adobe RGB_sRGB(Comparison)

Brad

[Linda G]

What you say makes sense up to a point.

If your ultimate goal is to print, you should leave your color space in the smaller space from the beginning. Going from a larger color space to a smaller one willl give you a lower quality color than starting in the smaller color space.

It would probably not be noticeable in most images, but if you want the best print possible, that would be the work flow recommended.

It's not like going from a large file to a small file, color is different.

Great graphics, by the way. Great job!

[AstroPic]

Hi people, what a great forum!

This topic has answered a lot of the practical issues about colour spaces, but I have a few theoretical technical questions which don't ssem to have been covered in here or the related links, regarding conversion from one colour space (eg S2 pro RAW) to another (eg sRGB)

Basically, what happens to the actual data? Each pixel has an RGB value in (say) 8 bits. This number is changed when converted from one space to another?

If the colour depicted in one colour space is outside that of another space, is it mapped onto a similar colour, discarded (treated as black or grey???)

Or are all the colours near the edges compressed/expanded, so that you still get colour differences, although they become 'wrong' at the edges?

Also, by definition, do these colour space definitions include bit depth?

Thanks in advance

Dave

[Linda G]

Leo,

Ilve heard the opposite but if it's not the best for web viewing, not the best for most printing, what use is it?

[Linda G]

..the main colourspace in the printing world is not Adobe RGB or sRGB but...


(drums please)

.... CMYK.

VERY true! But then, WHICH CMYK!! Again, check with your printer.

It's my understanding that very few printers, even and especially inkjet use Adobe rgb to print from but they CAN print from Adobe, just using it to fit in their own color space.

[AstroPic]

Hi again - not sure if people didn't know the answers to my question, or if it got lost by the web/not web debate.. but if anyone knows what is going on with the pixel values, please let me know!

[Linda G]

Sorry about that, we did kind of get off on a different subject...again.

As for your question, I can't really answer it completely, maybe someone here can but I CAN tell you I've seen images in Adobe RGB converted to SRGB lose much detail. I work with a Fuji Frontier that pirnts using the Srgb color space and when a file in Adobe RGB is sent to it, it clips the colors to match it's smaller color space. When this happens with this printer (all equipment software does it's own thing), the color that is out of it's 'gamut' is brought down to the nearest equivalent.

Say a boy has solid a red shirt on and you see plenty of detail in shadow areas, giving the boy form. Much of the lighter reds will be in the Adobe space and it will be brought into the srgb space, losing the detail, making the image more two dimentional. That's why we recommend using the Srgb from the beginning if you're going to have us print it.

Does that help at all?

[AstroPic]

Thanks for that Linda, I think for my needs Srgb is the way to go.

If there are any people who know more about the internal workings of these things, or where to find out in a digestible form, I am curious to know, I just have that sort of brain!

thanks

Dave

[tombrayne]

Oy! Tylenol please -- let's see if I can keep all this straight.

1st - Absolutely to Theo's post re: uses of color spaces. His only curveball which appears misunderstood was the CMYK reference. The thread had been referencing RGB spaces and desktop & minilab output. Both are RGB based. CMYK output is destined for offset/litho output devices and not used (generally, except to proof those devices) for desktop/minilab output. CMYK & offset profiles require XXL bottle of Tylenol.

2nd - Workflow from digital capture for multiple destinations. I always convert RAF files to Adobe RGB 16 bit files. This yields the widest gamut file with the greattest range and depth of colors (8 bit = 256 levels, 16 bit = 65,XXX levels). I always set the "View" profile to Adobe RGB, RelCol, Black Point on, to see the file in it's "pure" state -- NOT the default proof space, which in the US is CMYK SWOP 2 -- an offset CMYK space. Beat up the file in Photoshop however you please, but keep in 16 bit, so that any big edits made don't produce banding or posterization. When it's as you please, don't sharpen and name it "Whatever - Master". All output files will be dupes of this file, sharpened & converted to the proper color space & tagged w/ the appropriate output profile.

A coupla examples - A) Frontier output. Dupe your master file. Convert to 8 bit. Resize (up or down). Convert to sRGB space. If you've got a Dry Creek or other profile for the specific Frontier, go to View options & Proof SetUp, chose Custom & load the profile as your proofing profile. Toggle back & forth w/ Command Y (Mac) to see if there's significant difference between the file in A RGB and your output profile. (This is "softproofing" for output). If there's significant difference, I go back, make a 2nd dupe, keep the 1st in A RGB, the 2nd in the output profile & edit the 2nd to as closely match the A RGB as possible. Sharpen and you're there.
B) Epson output. Dupe. Convert to 8 bit if you want. Keep in A RGB. Profile to your choice of paper. Toggle Command Y again. Again, if significant difference, make a 2nd dupe, keep in output profile & edit it to as closely match the first in A RGB as possible. Sharpen & yere dere.

3rd - Pixel values -- it depends. If you're in a very saturated (extended) portion of the A RGB space & you convert to sRGB, you'll be compressing the values, losing information and of course changing the values. Look for instance at Brad's illustrations in say the deep greens. Converting in this case would compress or clip a measurable amount of green. Will you see it in the output....umm, maybe. For skin tones - nope, not really (or at least shouldn't).

So what's it all mean?? Guess the answer lies in what you want to do. If all you ever envision is getting Frontier output, sRGB is a wonderful thing. Labs are setup for it & you'll save a lot of dancin' in Photoshop. If however you plan to output to a wider gamut device e.g. inkjet, I'd stay in A RGB/16 bit and use the above dupe-as-need method. Uses more space, but hey! storage is cheap these days. And the real point is: how much quality do you want to squeeze out of your captures.

A coupla other notes. If you don't have a hardware profiled monitor, disregard everything I've written. Your monitor is your only link to photo "reality" & if it's not telling you the truth, then why bother. Pretty good reviews of devices at:

http://www.drycreekphoto.com/Learn/monitor_calibration_tools.htm

http://www.peimag.com/pdf/pei04/pei1112_04/rodneypei1112_04.pdf

http://www.shootsmarter.com/infocenter/wc026a.htm

I use a GretagMB EyeOne Display2, but looks like the Monaco may even be a touch better.

If you really, really want to get Epson output clear, find someone w/ a 4000 and beg, borrow or steal the included CD "Mastering Your Printer" Video Workshop. It's narrated by Mac Holbert of Nash Editions and is the most lucid "How To" I've encountered. In fact, I was wrong, wrong, wrong about a lot of this before I invested the hour in watching it.

Hope this helps.

More java & Tylenol please.

TB

[Linda G]

Oy! Tylenol please -- let's see if I can keep all this straight.

1st - Absolutely to Theo's post re: uses of color spaces. His only curveball which appears misunderstood was the CMYK reference. The thread had been referencing RGB spaces and desktop & minilab output. Both are RGB based. CMYK output is destined for offset/litho output devices and not used (generally, except to proof those devices) for desktop/minilab output. CMYK & offset profiles require XXL bottle of Tylenol.



More java & Tylenol please.

TB


Break out the Tylenol, Theo has it right. Most printers (Frontier included) print in CMYK but have an SRGB interface. Make sense? no, but it works.

[Linda G]

ooh, and also, if you're going with a Frontier, (I've seen the results, therefor the recommendation), if you're going to dupe, mark it frontier or srgb and START in srgb, never give it the larger color space and you'll get much, much better prints. the compression is not like compressing file size, we're talking random color here and you have no control. You get better images if you start in the color space you want in the end. But then, that's my preference, some aren't as picky.

[tombrayne]

Linda -

I'll give you that one - the inks on desktop & wide format printers are CMYK - but the interface is RGB. The driver makes the conversion from RGB data on the fly. Frontiers -- ?? Ummmmm, OK T'll take your word for it as you work w/ them every day.

TB

[tombrayne]

Linda ----

Not my experience that original space is sRGB for best Frontier output, but again you deal with it everyday. Guess I'd like to agree to disagree on that point.

TB

[Linda G]

Ut oh.

I may have to take a step back.

I work with both a Frontier and a Chromira ZBE....one of them is cmyk...but both have the rgb interface...I'll get back with you on which one. (duck) Can I have a get out of jail free card since I haven't been there for three weeks? The lab closed unexpectedly and I'm working hard to get the paperwork done to reopen. :righton:

[tombrayne]

Linda -

Step back & get out of jail card most assuredly allowed. My usual move is to fall forward - flat on my face.

For what it's worth, most of my output experience is either Epson DIY or offset press that gets handed off to a designer who deals w/ the CMYK voodoo

If I can remember far enough back to the original post, it seemed that the person specifically wanted to deal w/ a lab & avoid DIY, probably for quantity/time/cost reasons. I've been immersed (submerged??) w/ Epson output on a rather large scale over the last 8 months & for better or worse have learned a fair bit about the process. I'm going to jump off the cliff and say that if absolute quality is one's primary concern, that you know Photoshop, proper workflow & Epson quirks, one can produce much better output with their own printer than a lab can. Pedantic, yes. True, yes.
But then again, for various reasons, this might not have been the original poster's concern.

Color management -- ain't it fun??

Best Regards,

TB

[AstroPic]

Goodness me this is complicated!

I am newish to the RAW and colourspace issues.

I like working in 16 bit, 8 bit adjustments quickly lead to posterisation. It was a revelation to be able to use HS-V2 raw convertor and do the curves and white balance etc in 16 bit rather than 8.

But the tools are quite crude, even compared to photoshop elements, I would rather do this stuff in there in 16 bit. And keep it 16 til I had finished the editing! I have more experience in digital audio, and in that area, you want to keep as much bit depth as possible until the very last possible link in the production chain! (mastered for CD)

But can I see if I have this straight: basically we are talking of 3 colour spaces: Fuji RAW (which is a pretty big space), which can be converted to 16 bit Adobe RGB (a big space as well as having 16 bit depth - or is it the depth that gives it the space???) or sRGB - an 8 bit colour space, that is also less wide than adobe.

One of Linda's main points I think (please correct me if I am wrong) is that conversion from one to another is a necesary evil, the less conversions the better. Conversions also often involve clipping and/or are unpredictable. Also I guess, if you are working in the final colour space, your edits are showing you what you will actually get (monitor/paper differences aside!)

But if you go straight from Fuji RAW to sRGB, presumably there is some clipping there too? Maybe that workflow just means you never know that there is more detail in your original picture, and thus are more pleased with the (I am sure superb) print than you would have been if you knew that there used to be more colours?

Is there a version of sRGB that is 16 bit? that seems like the perfect solution if you are ending up printing on an sRGB printer...

or have I misunderstood everything?

[tombrayne]

Hi AstroPic --

1st - great on a couple of points -- yes it's complicated (still, for me) and it's good that you come from a background that you have some analogies for comparison.

I'll attempt to clarify a few things -- HS-V2 converter - crude compared to Elements - yup - welcome to the wonderful world of Fuji software. But in it's defense, once past the GUI or lack thereof, it does produce some nice looking files.

The Fuji (or any other) RAW file does not have an inherent color space. It's simply raw data that can be interpreted to "look" and "fit" a number of ways. So, prior to Theo's last post, we were indeed talking about only 2 color spaces. Adobe can be specified in 8 or 16 bit, sRGB in 8 bit only - which I see as two strikes against it - limited gamut and limited bit depth. sRGB is basically the lowest common denominator and used to describe uncalibrated monitors viewing the web. Gamut = overall range of colors, bit depth = # of colors and the subtlety of variation between colors (256 v. 65,XXX.)

Conversions - generally speaking, yes the less the better. When moving from a larger gamut to a smaller gamut you'll necessarily clip some values and you'll also see some rounding errors. Practically, I don't see the harm in moving from an AdobeRGB space to an sRGB space for minilab output, but again, I'm coming from the idea that one would want a master, multipurpose file that once built could then be duped and tweaked for a number of output destinations. Conversions can be predictable - if you softproof to the output profile (see previous posts). They aren't 100% accurate, but w/ a calibrated monitor (well, really profiled monitor, but I didn't want to muck things up more), you can get a very good idea what your conversion or your output to a given device will look like.

Profiles - there's a big old bunch of 'em and they're used to describe different things, hence the confusion. All profiles interpret the deficiencies of the particular device and transform them to a common language, if you will. Input profiles describe capture devices. Monitor profiles map the deficiencies of your screen & "bend" the data so that say an RGB value of 128, 128, 128 really does look medium gray on screen. Output profiles measure the deficiencies of printer/press and the paper/substrate and "bend" the data to compensate as much as possible to match the file's data - given the destination device's gamut.

When you said:

"But if you go straight from Fuji RAW to sRGB, presumably there is some clipping there too? Maybe that workflow just means you never know that there is more detail in your original picture, and thus are more pleased with the (I am sure superb) print than you would have been if you knew that there used to be more colours?"

you didn't misunderstand anything -- you absolutely got the essence of the idea.

Actually, this was good for me - forced me to go back & reread a bit to clarify my thinking. I'd really recommend "Real World Photoshop" and "Real World Color Management", both by David Blatner and Brucer Fraser. Tough slogging, but they explain things very well - including Lab space, the discussion of which would only at this point serve to muck things up a bit more (hint - it's device independent and built on the way in which human vision perceives color). Ck Amazon for the titles.

Hope this helps. OK, now where's that Tylenol?

TB

[Linda G]

I pass you the tylenol! A brew, too, if you want.

I do think I'm going to have to do an experiment for myself and take a couple of images with many colors, tones and ranges of contrast and start them out as Adobe rgb, convert to srgb, then take the same files and start their lives as srgb, print them and see if I can tell a difference. I was told that's not going to get the best quality but now I need to see for myself.

I DO know we've had trouble with some colors, especially reds, when doing this. I worked for two days on an image of a little boy in a red shirt that when printed, looked like someone just splashed red paint on his little body...NO details in the shirt at all. Day two, we found it was in Adobe rgb, converted it to srgb and worked then to get some of the detail back so it would print the variations in red to make the body contours.

This was in year one of our having the Fuji and the file came from a friend in Italy, he had his local lab print it unsuccessfully and thought he was going to send all his stuff to us after he saw the quality change but I explained why he had the image he had...he learned, and took files in srgb to his local Frontier and got great prints.

[AstroPic]

Thanks for the further clarifications and further reading! Its beginning to make some sense to me now, both theoretical and also practical things to look out for

[tombrayne]

Hi Linda -

I'm not at MY computer right now, so I don't have access to my files for a quick Photoshop spin.

I've seen the weirdness when going from A RGB to sRGB. Here's where I've seen it: When one assigns an sRGB profile to an A RGB profile w/ lotsa red, things do get a bit nuclear. When you convert to SRGB - actually change that data when tagging the file, the problem seems to not be present. So, my mantra is convert, not assign. Same thing when tossing files at the web. Now I gotta go back to Real World to reread and remember exactly why.

Sooooo............maybe try 3 possibilities in your test -- sRGB capture (or RAF conversion), A RGB capture assigned to sRGB and A RGB capture converted to sRGB. I'd like to know your results.

Best Regards,

TB

[Linda G]

The argb would be unceremoniously converted in the Fuji software but yeah...all the variables.

[Sleeping Bear]

I've read the thread and now my head hurts. The following seems to make more sense to me at this time:

(lennon/mccartney)

Picture yourself on a boat in a river
With tangerine trees and marmalade skies
Somebody calls you, you answer quite slowly
A girl with kaleidoscope eyes

Cellophane flowers of yellow and green
Towering over your head
Look for the girl with the sun in her eyes
And she’s gone

Lucy in the sky with diamonds
Lucy in the sky with diamonds
Lucy in the sky with diamonds, ah

Follow her down to a bridge by a fountain
Where rocking horse people eat marshmallow pies
Everyone smiles as you drift past the flowers
That grow so incredibly high

Newspaper taxies appear on the shores
Waiting to take you away
Climb in the back with your head in the clouds
And you’re gone

Lucy in the sky with diamonds
Lucy in the sky with diamonds
Lucy in the sky with diamonds, ah

Picture yourself in a train in a station
With plasticine porters with looking glass ties
Suddenly someone is there at the turnstile
The girl with kaleidoscope eyes

Lucy in the sky with diamonds
Lucy in the sky with diamonds
Lucy in the sky with diamonds, ah
Lucy in the sky with diamonds
Lucy in the sky with diamonds
Lucy in the sky with diamonds, ah



Would we change the tangerine skies if we kept it in srgb?

:rofl:

[HulaMike]

Ron, take your boots off and lie down now............ :rolleyes:

[Linda G]

*sigh*







that was all I wanted to say but the program said it was too short so ignore this and I can post.

[tombrayne]

Linda, Ron, & Mike -

Y'all got that right.

In reality, there's no way I wanted to learn all this junk. In reality, if I was to be successful at digital capture and output I had to learn all this junk.

TB

[Sleeping Bear]

Ron, take your boots off and lie down now............ :rolleyes:

Thank you, doctor. Do you think it all stems from my being abducted by aliens when I was nine years old? Or is it all just a dream by a different me in another space and time? A me that already knows this color schmolor? Say it's so, doc!!

[Sleeping Bear]

Linda, Ron, & Mike -

Y'all got that right.

In reality, there's no way I wanted to learn all this junk. In reality, if I was to be successful at digital capture and output I had to learn all this junk.

TB

I agree and I'm thankful for the info. Now I just need to read and digest. Hmmm...I should start a new magazine and call it 'Reader's Digest'. Do you think it'll work? :dunce:

[Sleeping Bear]

*sigh*







that was all I wanted to say but the program said it was too short so ignore this and I can post.


Oh oh. It's never good when they sigh like that. :lol:

[jknights]

I just wanted to bring this to your attention, it was quite interesting using Apple's 'Colorsync Utility' to be able to view and rotate profiles while one is displayed within the other, as the article describes.

http://www.luminous-landscape.com/tutorials/prophoto-rgb.shtml

These are also in PS CS2 as well so we can start to use them if we want.

Unfortunately it would be good to be able to profile the camera and upload it back into the camera. Nikon cameras can do this via Nikon Capture but I haven't actually tried it.