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1. Re: convert or assigned profile?
c.pfaffenbichler May 25, 2011 7:23 AM (in response to mikeci1)Why is there a difference between convert profile to and assign profile?
I know the Forum Search has been messed up for some time now, so that can seem rather fruitless.
But have you read the relevant chapters in the Help?
Anyway, converting changes the pixels’ RGB-values to maintain the color impression while assigning leaves the numeric values unchanged but uses a different profile which can cause the appearance to change significantly.
The RGB-values without a profile are not wholly meaningless, but fairly vague, in that they may describe one point as darker or more »red« than another – but which »red« it actually represents is either stated in the profile or will be made manifest on output.
This site has been recommended as reading for people who are new to color management:
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2. Re: convert or assigned profile?
charles badland May 25, 2011 7:50 AM (in response to c.pfaffenbichler)Language translation can be a good analogy for Convert/Assign:
Say you have the word “ONCE”, but you don’t know its origin language. What does the word mean?
If you assign English to it, it takes the meaning “one time”. If you assign Spanish to it, the word “ONCE” will now mean “eleven”.
Exact same letters, O N C E, depending what language, can have very different meanings.
If you take the word ONCE, that is tagged as Spanish, and you want to CONVERT it to English, you’ll have to change the letters (O N C E to E L E V E N) to retain its meaning.
So think of the letters of the word as RGB numbers and the color they appear as the meaning of those letters. When you Convert a file, the RGB numbers change to retaining the color “meaning”. When you Assign a color profile, the RGB numbers stay the same, but the color “meaning” will be different.
You normally would never Assign a new color profile to an image already tagged with a correct profile.
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3. Re: convert or assigned profile?
mikeci1 May 25, 2011 8:13 AM (in response to c.pfaffenbichler)c.pfaffenbichler,
Thanks for the fast comeback. I’m reading as fast as I can trying to get up to speed. For 30 yrs I shot film and never had to even think about any of these things like profiles, white balance and the like. Just sent the slide or the neg off to the printer and wait for the print to come back. For the past three yrs I have taken a couple of courses for Photoshop but it seems profiles were not covered. I have come to rely on forums as a sign post to get me started in the right direction as I travel down this rocky minefield that is Photoshop.
Thanks again for the pointer,
Mike
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4. Re: convert or assigned profile?
mikeci1 May 25, 2011 8:23 AM (in response to charles badland)Hi Charlie,
thanks I get the analogy. Should I readjust the converted file so it matches the original pro photo RGB before sending it on?
thanks again,
Mike
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5. Re: convert or assigned profile?
charles badland May 25, 2011 8:49 AM (in response to mikeci1)Should I readjust the converted file so it matches the original pro photo RGB before sending it on?
I don't know your workflow history...
but if you Assigned sRGB to a pro photo RGB, then yes, by all means re-assign Pro Photo RGB to the file.
If you Converted Pro Photo to sRGB, well you may have lost of bit of out of gamut color, and it would do no good to re-convert back. Just keep as is.
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6. Re: convert or assigned profile?
mikeci1 May 25, 2011 9:25 AM (in response to charles badland)this subject is starting to hurt my head. I feel like I'm trying to herd cats! basically I import a raw file and convert it to DNG in lightroom then make any gross adjustments i.e. crop, sharpening, contrast, brightness etc. Then send it onto photoshop which by default gives the file a pro photo profile then make a duplicate copy and convert the copy to sRGB and output as a jpg to send to the printer (this is the profile and file format the company wants). I realize I lose some gamut when I convert but will at least regain some of the brightness/ contrast and adjust the gains on the colors if I adjust the converted file to try to match the pro photo file?
Mike
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7. Re: convert or assigned profile?
charles badland May 25, 2011 11:07 AM (in response to mikeci1)Hi Mike,
I don't work in Pro Photo. And my photo lab respects my AdobeRGB space. I'm not sure if there is advantage to edit in Pro Photo only to convert to sRGB. There might be if you are working high-bit Pro Photo. Maybe someone else can shed some light on that. It is a cat-herding headache.
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8. Re: convert or assigned profile?
pvanderh May 25, 2011 12:37 PM (in response to mikeci1)Every so often a image will work to simply convert to profile but I find most times it falls short. If that fails this is how I go about it. sRGB, ProPhoto... it only matters that the source is the same output as the target (CMYK flavor to CMYK flavor or RGB flavor to RGB flavor). For simplicity I am explaining RGB to RGB. Open image > view > proof preview > Custom> Desired target space (sRGB) > Check Preserve RGB numbers > click OK. At this point you will see the end result but the original information and numbers remain and alows you to better leverage that info for adjustments. Now you can make the needed adjustments with layers and keep everthing in the original PSD in a nondestructive way. Often I will duplicate the image in a new window and preview that in the source profile along side of the one that I am working for comparison. Once I have the image looking the way that I want simply save a copy and assign the target profile to that copy (edit > assign profile), export as a JPG.
Charles, I love the analogy and surely will use it in the future.
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9. Re: convert or assigned profile?
charles badland May 25, 2011 12:53 PM (in response to pvanderh)Charles, I love the analogy and surely will use it in the future.
I wish I could take credit for it. I stole it from another forum participant here.
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10. Re: convert or assigned profile?
Printer_Rick May 25, 2011 3:00 PM (in response to mikeci1)Hi Mike
There was a very amusing discussion about this some time ago, here is a link if you are interested:
http://forums.adobe.com/thread/453025
mikeci1 wrote:
this subject is starting to hurt my head. I feel like I'm trying to herd cats! basically I import a raw file and convert it to DNG in lightroom then make any gross adjustments i.e. crop, sharpening, contrast, brightness etc. Then send it onto photoshop which by default gives the file a pro photo profile then make a duplicate copy and convert the copy to sRGB and output as a jpg to send to the printer (this is the profile and file format the company wants). I realize I lose some gamut when I convert but will at least regain some of the brightness/ contrast and adjust the gains on the colors if I adjust the converted file to try to match the pro photo file?
Mike
I would make sure in your color settings that preserve embedded profiles is enabled. I say that because if you open up one of your sRGB outputs later on with this option disabled, you are viewing the sRGB numbers in your Pro Photo working space which is not a good approach.
If you have a Pro Photo that needs to output sRGB, definitely convert, and the perceptual (photographic) rendering may yield best results, although you may prefer relative colorimetric.
If any Pro Photo colors that reside beyond the boundaries of sRGB take a huge hit, then you have the option of an adjustment layer in the sRGB result to make it more satisfactory. If you start to pile on a lot of adjustment layers then 16 bit can help reduce the damage of the numerous adjustments. Hope this helps.
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11. Re: convert or assigned profile?
Mike Ornellas May 25, 2011 3:20 PM (in response to mikeci1)Oh -
that one is good reading. One of my favorites actually.
When your brain turns to much, just forget everything you have read and move on. Your outcome will be about the same.
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12. Re: convert or assigned profile?
Printer_Rick May 25, 2011 3:41 PM (in response to Mike Ornellas)Well said Mike. My brain gets fried a little more each day – the more you learn, the less you know. I definitely am further behind than when I first started that old thread.
To the other Mike, you might get additional insight in the color management forum (emphasis on might, of course).
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13. Re: convert or assigned profile?
mikeci1 May 26, 2011 4:07 AM (in response to Printer_Rick)Rick,
At your suggestion I read your thread on the same discussion;
http://forums.adobe.com/thread/453025
even though the thread seems to be about converting to CMYK a lot of the talk applied to my problem. I now realize what I don’t know about color management could fill volumes. After the first page I bypassed the aspirin and went straight for the Thorazine. I went from a cat-herding headache to a lizard-chasing migraine. I’m still trying to get through it (just started the third page). I’m having some trouble cutting through the fat and the grizzle to get to the meat of the discussion but that’s what these forums are all about. Threads sometimes take on a life of there own.
It’s starting to remind me of a honking gaggle of art experts discussing the finer points of the painting "Polar Bear in a Snowstorm" or if Pollock drizzled the paint clockwise or counterclockwise.
I will continue to read that thread and other threads and articles that were suggested. Hopefully I will get at least a half-assed working knowledge of color management withregards to fine art printing.
But I think when all is said and done, for me, it will be like sausage, it tastes really good but I'm not sure I want to know how it’s made.
Thanks for all the help.
Mike
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14. Re: convert or assigned profile?
charles badland May 26, 2011 6:04 AM (in response to mikeci1)Photographer Martin Evening has a pdf available of his book chapter on Color Managment:
http://www.photoshopforphotographers.com/pscs3/download/PSCS3_colmanage.pdf
It is a few years old now, but still relevant. It has a good description of WHY there is a need for color management and some helpful visual examples.
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15. Re: convert or assigned profile?
mikeci1 May 26, 2011 7:43 AM (in response to charles badland)thanx charles I'll ad it to my "to read list"
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16. Re: convert or assigned profile?
Mike Ornellas May 26, 2011 4:59 PM (in response to mikeci1)Color management works very well. The implementation is completely outdated for the average user. It does not have to be as hard as it is to get good consistent color, and it's unfortunate that Adobe believes in supplying you the tools, but provides little in the way of how to use them. This is why the majority of the developers that work with Adobe are book authors.Unfortunately, all the book authors in the world can't seem to have a realistic World perspective on trying to solve some of the most common challenges that plague many areas of industry.
It's still a huge mystery to many what the difference is between assign and convert and when to use one or the other. I had to give an impromptu sermon about the difference between the two just last week in the office and at that point the light bulb came on, but still many find the subject annoying at best.
This is my point exactly, The subject is annoying to the point of ignorance and that is the whole problem with the current implementation of color manglement. People should not have to deal with color management and it should be seamless unless you want to dig deeper to customize a specific need.
The problem with typing is that typing gets in the way of thinking. The same goes for color management's implementation. It's in the way for the majority of users.
good luck with your treatment.
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17. Re: convert or assigned profile?
Printer_Rick May 27, 2011 2:36 PM (in response to Mike Ornellas)Looking past the know how of color management is the the cost. Custom profiling packages and good monitors aren't exactly free.
And the up-front equipment is small potatoes compared to the time and effort. It's not enough to have the hardware and software, you have to use it.
Color manglement is maintenance. Devices drift. Everyone involved from image capture to final product has to let go of subjectivity and assumptions to avoid a broken system. Three people might be on the same page. But with a half dozen, invariably someone skips past the boring stuff, on to the next chapter.
There are too many people who equate ICC with calibration. One is a color space, and the other is measurement and correction. Just the other day a technician tried to tell me that GRACoL is "gray balance" and an appropriate color space for uncoated. That is another CMYK story and unrelated to the OP's color concerns but it is one of many symptoms of a growing problem.
Nothing ages like compounded confusion. Except for maybe Pantone books.




