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Author Topic: CMYK conversion tool?  (Read 24692 times)

Kirk Gittings

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CMYK conversion tool?
« on: April 14, 2007, 06:35:31 pm »

There is a growing need, in my experience, for photographers to do their own CMYK conversions. Whether you like this trend or not it is becoming a fact of life if you want your images to look good in print. I don't want to got into the politics or economics of this here. As any professional knows the PS tool for this conversion is very crude and soft proofing with the printers profile only helps so much. In the film days CMYK conversions were usually done by pre press professionals, who oftentimes masters at this with tons of daily experience.

I can see the need for a PS plugin that that would help do better CMYK conversions. This plugin would incorporate side by side RGB and CMYK thumbnails (softproofing with the appropriate profile) and perhaps some kind of replacement tint picker that allowed you to pick Pantone colors that approximated the RGB values.

I am not the guy to develop this tool, but I can sure see the need for it. Am I alone in this. Is there broader interest in such a plugin?
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Schewe

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« Reply #1 on: April 14, 2007, 08:08:08 pm »

Uh, you talking about sheet-fed or web press? Because if you are talking about web press (used in the majority of magazines printed) here in the US, SWOP is pretty much the standard with TR-001 being the spectral properties of SWOP. So, if you use Photoshop's default SWOP coated profile you will get a very accurate reproduction from Photoshop. Read: Preparing Images for Delivery (it's a 7.1MB PDF)

To be blunt, if you think Photoshop's RGB>CMYK conversion is "crude" then you probably ain't doing it right.

If you are talking about sheet-fed then there really is no alternative to getting an accurate profile of the exact press, ink and paper combo you will be printing to. And a plug-in ain't gonna help you there. Only a profile will give you the required color transform that will provide accurate reproductions. The politics of printing and pre-press so far have made that difficult. But there are printers out there that WILL work with you.

I don't disagree that photographers, if they are so inclined, SHOULD take control of their own reproduction-if feasible...but sometimes, particularly when dealing with editorial clients who take a while making final selections doing final pre-press work on an entire shoot isn't cost effective. You only want to work on the final images, not everything in a shoot.

Commercial shooters who can work with the art director and make final selections before retouching can easily also include final RGB>CMYK conversions. Getting a rip for an Epson printer (3800 or above) can provide very accurate CMYK proofs upon which you and the client can depend.

But...there never will be a magic button to push to make reproduction easy...it'll always take skill and knowledge.
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Kirk Gittings

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« Reply #2 on: April 15, 2007, 01:39:10 am »

I have read and regularly use your treatment on the subject, but I do not see the current state of CMYK conversion techniques to be the final word on the subject. It strikes me that there is much room for improvement. Also, I don't consider many of the upgraded tools in PS 3 to be magic bullets, like b&w conversion etc., but they are improved tools. They all require skill and aesthetic sensibilities to do them well. I fail to see why CMYK conversion is any different.
« Last Edit: April 15, 2007, 01:39:39 am by Kirk Gittings »
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Schewe

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« Reply #3 on: April 15, 2007, 02:54:19 am »

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It strikes me that there is much room for improvement.
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Improve what and how? You ain't gonna get the CMYK process any better...you can go spot or special colors, 6 color or whatever, but the fact is, CMYK ink on paper sucks...it'll always suck unless you change the entire printing industry...

I suppose somebody like Bill Atkinson might be able to come up with something different...he came up with an entirely new approach for the printer that printed his Within the Stone book...See: [a href=\"http://www.billatkinson.com/SpecialOffers.html]Bill's Book[/url]. He used a special process to profile and literally expand the normal gamut of color that the printer's press could output...but I'm pretty sure he actually used Photoshop to do the conversions...if you want to read how Bill did it, download his PDF Making Within the Stone (note, it's a 65mb download and doesn't really get into how he did the separations)
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Kirk Gittings

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« Reply #4 on: April 15, 2007, 09:09:04 pm »

I understand your points. CMYK ink on paper does suck but this is how many of us have to make a living and unlike the old film days when prepress professionals did the conversions it is now the shooter or magazine art dept people doing it. The result may not get any better than the prepress days but the conversion process could be streamlined by some additional software. Both the photographers and the magazine people currently doing most of the conversions would benefit from and potentially be a market for such software. This is a real issue.
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Schewe

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« Reply #5 on: April 16, 2007, 01:06:26 am »

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Both the photographers and the magazine people currently doing most of the conversions would benefit from and potentially be a market for such software. This is a real issue.
[a href=\"index.php?act=findpost&pid=112593\"][{POST_SNAPBACK}][/a]

Yeah, well, it's called Photoshop. . .and it works really well with good profiles and to be honest, it works a _LOT_ better than the "good ole' days"...I've been there and wear the scars of prepress and printers claiming they couldn't reproduce my 8 x 10 chrome cause I didn't shoot with enough fill light or I under exposed the chrome 1/2 stop to get saturation. They eventually DID get it right, but not untill after about a 1/2 dozen rounds of proofs-which they happily billed to the art director.

In 1989, the Printing Industry of America (PIA) did a secret survey (I won't tell you how I found out) that indicated that on average, it took 3.2 proofs before a client "bought" the color...the secret was that even in 1989, the images did not have to be rescanned, just corrected and reproofed...one of the biggest boondoggles in the printing industry was charging clients for proofs...over and over until the printer finally got it right.

Fast forward to today and if you have half a clue and a decent printer profile and display profile, knowlegable users can softproof and correct an image and pretty much nail it for tone & color before even doing a proof. It's ain't that hard today and it's a whole lot better than it was 10 years ago.

The key is to know what you are doing...which, in general neither agencies nor magazine production departments do. And the "knowlegable" people at the printers are gone (generally, retired since they were so old). So if a photographer really wants a quality job, they should learn how to do it themselves-if there's time. Which is another whole can-o-worms...

No, you just aren't gonna get push button color separation...
« Last Edit: April 16, 2007, 01:07:25 am by Schewe »
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Kirk Gittings

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« Reply #6 on: April 16, 2007, 01:27:43 am »

Quote
They eventually DID get it right, but not untill after about a 1/2 dozen rounds of proofs-which they happily billed to the art director.

It was the good old days because, with the larger web presses and mid to large magazines, I could be reasonably assured that a diligent art director would get the color right after a few proofs, but I didn't usually have to get involved in it and could get back to what I do best. Now if I give it to them to convert I am almost guaranteed it will be done the down and dirty way and look like crap. Otherwise, I do it myself and oftentimes spend more time on the conversions than I did shooting. Yes I would like an easier way. Shoot me for being so presumptuous as to want some software that would make the task easier.
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Schewe

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« Reply #7 on: April 16, 2007, 01:43:52 am »

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Shoot me for being so presumptuous as to want some software that would make the task easier.
[a href=\"index.php?act=findpost&pid=112620\"][{POST_SNAPBACK}][/a]

Naw...ya just got to train your clients to be willing to pay _YOU_ to do it right (and quit blaming it on you when somebody down the road screws it up).

:~)

It's the "down and dirty" approach that is killing magazine reproduction...believe it or not, most magazines simply to a mode change, RGB>CMYK for conversions...with Photoshop set to "default". For web press, that ain't the worst thing in the world (unless they are using Photoshop 4.0) but for sheetfed, that's a far cry from optimal.

But. . .that's already pretty much the standard "push button approach". The ONLY way to do it better is to actually take the time to soft proof in the final CMYK profile and make the image look as good as it can in CMYK. Unfortunately, software can't make decisions for you without properly setting up the software (like having a good profile and printer profile) and then using your eyes and judgement.

So, all you would end up with is an automated, push button "down and dirty" method of doing RGB>CMYK conversions. It's really tough to save people from themselves...
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iGuy

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« Reply #8 on: April 20, 2007, 11:04:07 pm »

If I understand the arguments correctly, it seems that the art of photography in the digital age has expanded to encompass colour conversion.

This is not unlike my original industry, Technical Writing, when in the late 1980s writers had to become designers in order to understand and use the new desktop publishing tools that were suddenly available.

Those of us old enough to remember those days remember that some did it well, and others, not so.

A dialogue began between writers and designers and a new hybrid was born. I get the sense that a similar process is occurring in digital photography.

I can understand the desire for tools to ease the burden of colour conversion but I also understand that reasonably good tools already exist, however awkward some may find them.

It's the law of diminishing returns. How many would pay the cost of developing a truly intuitive tool when a not-so-intuitive one already exists?

As with most things in life I can see both sides of this polite, gentlemanly debate.  

~iGuy
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pfigen

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« Reply #9 on: April 25, 2007, 12:14:25 pm »

"It was the good old days because, with the larger web presses and mid to large magazines, I could be reasonably assured that a diligent art director would get the color right after a few proofs, but I didn't usually have to get involved in it and could get back to what I do best. Now if I give it to them to convert I am almost guaranteed it will be done the down and dirty way and look like crap. Otherwise, I do it myself and oftentimes spend more time on the conversions than I did shooting. Yes I would like an easier way. Shoot me for being so presumptuous as to want some software that would make the task easier."

Kirk,

What exactly are you seeing that you don't like? In instances where you have seen results you don't like have you followed up and found out exactly what happened to produce substandard printing? The good old days you seem to be pining for weren't all that good, and were only good for one specific output. The CMYK conversions were done by algorhythms plugged into drum scanners that converted scanner RGB to CMYK on the fly. There is nothing inherently better about that than the current state of technology, where, if you have the right tools (and most don't), you can generate custom icc profiles that actually surpass the quality of those oversharpened proprietary scans.

Digital cameras have made this necessary as the old prepress shops didn't and by and large, still don't understand what to do with RGB files. You should be celebrating the level of control you currently have instead of complaining. The tools are there built right into Photoshop, and combined with really affordable spectrophotometers and profiling software, for only a few thousand dollars, you too, can be state of the art.

I've been doing my own prepress file conversions with my own custom profiles for at least the last seven years, and the state of the art now, I can tell you, is very, very good. High end shops here in Los Angeles are always telling me that they can't believe how close my Epson proofs are to their proofs. It's no surprise to me, but I guess it is to them. Our files proof correctly about 98 percent on the first round of proofs. That rarely happened in the good old days. I can't tell you how many times I have had to send files off that were only proofed on a Sony Artisan and they all print very well.

The tools are there if you learn how to use them. They work better than ever. I'm not complaining, I'm actually very happy where things are.
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photo570

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« Reply #10 on: April 26, 2007, 04:41:59 am »

"Shoot me for being so presumptuous as to want some software that would make the task easier."

I don't think anyone want's to shoot you.  

We are just not sure what you are unhappy with.

I agree with most of what has been said previously so won't repeat most of it. Yes good profiles are a must, and can do wonders over the "old way" but for certain images this approach falls flat.   I refer of course the the dreaded out of gamut "colours" fashion designers love. (Yes I am not from North America). Just last month I had to convert a screaming blue dress from RGB (Phase P25) to sheet-fed (340 total ink, Toyo inks, Med GCR, 25%UCA, 12%DG). It looked terrible. The RGB file was great, but no matter how it was converted, using various rendering intents, it just lost all detail as the Cyan & Magenta plates were pretty much solid. So what to do?

I think this is the type of situation Kirk refers to??

There is no magic bullet. You simply need the experience, which unfortunately takes time to gain, to know how to then edit your image accordingly to achieve the best compromise, because you just can't reproduce some colours in CMYK. But you can make them look a hell of a lot better than you get from a straight conversion.

In this case we simply masked the areas of the dress where detail was an important part of the design concept, i.e. a ruffled bodice, and cut and pasted the complimentary (Yellow) channel into the black and then tweeked it with a curve to increase the contrast and detail locally.

Some times there is no substitute for additional retouch in the final output space after conversion.

Ces't la vie.

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Jason berge
« Last Edit: April 26, 2007, 05:02:41 am by photo570 »
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pfigen

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« Reply #11 on: April 26, 2007, 04:58:12 pm »

"to sheet-fed (340 total ink, Toyo inks, Med GCR, 25%UCA, 12%DG). It looked terrible. The RGB file was great, but no matter how it was converted, using various rendering intents, it just lost all detail as the Cyan & Magenta plates were pretty much solid. So what to do? "

Of course, there are times when you have to resort to plate blending, pasting copies of channels or even pasting modified channels directly from an RGB version of your file. Custom profiles are not going to change that, but they often make that type of work needed less often. The other thing is that your alternate rendering intents actually work. You've only got one option when you use the CMYK Classic engine - that's Relative Colorimetric. Build out a Gretag profile using all three and Percerptual renderings available, which I've done, and you'd be surprised at how well they work when the situation is called for.

"I think this is the type of situation Kirk refers to??"

We won't know until he tell us exactly where things are falling short for him.

"There is no magic bullet. You simply need the experience, which unfortunately takes time to gain, to know how to then edit your image accordingly to achieve the best compromise, because you just can't reproduce some colours in CMYK. But you can make them look a hell of a lot better than you get from a straight conversion."

A straight conversion through the old CMYK setup can be (and usually is) a lot different than one through a custom profile. Neither are panaceas, but at least the custom profile is based on actual measurements of either the press or the proofing system that the press is calibrated to. You can plug in custom measurements into the CMYK Setup Custom Inks boxes and get a lot closer to what a real custom profile gives you, but you're still minus the rendering intents and the exact dot gain numbers.

For the vast majority of images I deal with, and I was at another press check this morning, a conversion to the custom profile combined with fine tuning the white and black point and maybe a quick Selective Color tweak is all that is needed. The problem images need to dealt with on an as needed basis.
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Kirk Gittings

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« Reply #12 on: April 26, 2007, 06:38:58 pm »

Sorry, I thought this thread was dead. I've been meeting deadlines. And I'm still in the middle of them. So I need to be brief.

Quote
For the vast majority of images I deal with, and I was at another press check this morning, a conversion to the custom profile combined with fine tuning the white and black point and maybe a quick Selective Color tweak is all that is needed. The problem images need to dealt with on an as needed basis.
[a href=\"index.php?act=findpost&pid=114414\"][{POST_SNAPBACK}][/a]

This is exactly what I do and I usually use a custom profile from the web press which happens to print many of the magazines I shoot for, American Web in Denver.

My point is that I think there is room for a good plugin for CMYK conversion that both organizes the usual tools (sftproofing capabilities, profiles, side by side, before and after views, black background, on-off buttons for simulating paper white/black ink, curve/levels with white/black point, hue/saturation, selective color,  etc.) and perhaps more sophisticated tools that are not currently part of my usual workflow.

I agree with Schewe in principle about the state of the market (and I have learned allot from him on this subject). But, particularly outside the major markets, it is going to be up to shooters and magazine art people to do conversions on the fly. I would rather not do it, but in many cases that  means crappy reproductions. In the outback you have to know how to do it.

However about plugins--most plugins don't do much more than organize varied PS tools better for a particular task though sometimes they add some magic. There is room for one such plugin here.  And there is a market for it in people like me, small magazines, ad agencies etc. Sure all the tools are there in PS, but as I see it more and more of this kind of crap is going to fall back on photographers. Why not develop tools to make it better and easier? I am not the one to do it. I don't have the skills or the time to develop them, though I would certainly like to contribute.
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pfigen

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« Reply #13 on: April 26, 2007, 07:09:59 pm »

I guess I just don't see it the same way you do. I think the tools are very easy to access and use. I really never find myself wondering why they are laid out "better" or more efficiently because, the way I work, they are very efficient and make perfect sense. Of course, just adding a few Function Key shortcuts helps workflow a great deal. Most tools are just a keystroke away and everything that needs to be open, is, on a second screen. I suppose that if it bothers you enough, you should put in a feature request at Adobe. Every once in a while they actually implement user requests.
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photo570

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« Reply #14 on: April 26, 2007, 09:58:35 pm »

Quote
"to sheet-fed (340 total ink, Toyo inks, Med GCR, 25%UCA, 12%DG). It looked terrible. The RGB file was great, but no matter how it was converted, using various rendering intents, it just lost all detail as the Cyan & Magenta plates were pretty much solid. So what to do? "

Of course, there are times when you have to resort to plate blending, pasting copies of channels or even pasting modified channels directly from an RGB version of your file. Custom profiles are not going to change that, but they often make that type of work needed less often. The other thing is that your alternate rendering intents actually work. You've only got one option when you use the CMYK Classic engine - that's Relative Colorimetric. Build out a Gretag profile using all three and Percerptual renderings available, which I've done, and you'd be surprised at how well they work when the situation is called for.

"I think this is the type of situation Kirk refers to??"

We won't know until he tell us exactly where things are falling short for him.

"There is no magic bullet. You simply need the experience, which unfortunately takes time to gain, to know how to then edit your image accordingly to achieve the best compromise, because you just can't reproduce some colours in CMYK. But you can make them look a hell of a lot better than you get from a straight conversion."

A straight conversion through the old CMYK setup can be (and usually is) a lot different than one through a custom profile. Neither are panaceas, but at least the custom profile is based on actual measurements of either the press or the proofing system that the press is calibrated to. You can plug in custom measurements into the CMYK Setup Custom Inks boxes and get a lot closer to what a real custom profile gives you, but you're still minus the rendering intents and the exact dot gain numbers.

For the vast majority of images I deal with, and I was at another press check this morning, a conversion to the custom profile combined with fine tuning the white and black point and maybe a quick Selective Color tweak is all that is needed. The problem images need to dealt with on an as needed basis.
[a href=\"index.php?act=findpost&pid=114414\"][{POST_SNAPBACK}][/a]


Sorry for the confusion.

I was using custom profiles, the description was given just as an indication of the conditions on the press. I agree that custom profiles are the way to go almost all of the time.

I was just suggesting a scenario that may be what is causing Kirk to wish for a "plug in".

 
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Kirk Gittings

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« Reply #15 on: April 27, 2007, 12:06:47 am »

I appreciate your input on this. While I have over 30 years experience shooting for print, it is only the last couple of years that I have had to get involved directly in the prepress preparation of files. Some of you guys clearly have allot more experience than I do with this. I am processing some files of an interior house shoot right now to be delivered tomorrow.

For example. right now as usual I have the printers profile loaded for soft proofing and gamut warning on. I have, Curves, Levels, Hue/Saturation and Selective Color loaded as adjustment layers. It would be very useful to be able to have both Hue/Saturation and Selective Color up and operational simultaneously (or a set of sliders that combined all the functions) as everything is interrelated-rather than closing one out and opening the other. Something like the B,T&H palettes in ACR CS3 but with dual before (in whatever color space you choose) and softproofed CMYK after image displays.

While this may either, not be possible, cost effective or whatever, I am certain that it would greatly improve my workflow on conversions.
« Last Edit: April 27, 2007, 12:18:06 am by Kirk Gittings »
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pfigen

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« Reply #16 on: April 27, 2007, 01:42:44 pm »

Kirk,

I just think you need to get more comfortable with the corrent crop of tools and spend a few years correcting images for print. They really do work very well, and there are good reasons for not combining functionality, even when it might seem like it would make your life easier. There are so many times that you need to affect different part of the image selectively, it just doesn't seem like a big deal to have multiple adjustment layers. It wasn't too long ago when we had to duplicate entire layers many times to have something close to the functionality we currrently enjoy.
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Kirk Gittings

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« Reply #17 on: April 27, 2007, 02:37:20 pm »

I just hate this process of "dulling down" my images. I didn't mind it so much when others were doing it. It kind of like the old saying not wanting to know how sausages are made.
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pfigen

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« Reply #18 on: April 27, 2007, 02:52:43 pm »

I prefer the attitude of confronting the challenge of offset lithography and absolutely enjoy the process of making the images pop as much as possible in a medium that makes that as difficult as possible. Sure, there are times when things just suck, but if you're printing at a good printer on nice paper, it's really amazing what you can do with just four colors. Now if you have the luxury of touch plate, then you can really sparkle. You learn through trial and error on this stuff. Every job I do, I go back and analize where I could have made if better the next time around.
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Kirk Gittings

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« Reply #19 on: April 27, 2007, 06:56:49 pm »

Unfortunately, I am talking about mass market magazines on web presses. I just went to a meeting at one of them. They are not even using the icc profile of the web press that they supplied me! Poor monitor calibration etc. etc. I actually ended up correcting the barrel distortion and CA of another photographer's work, because they didn't know how.
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