Luminous Landscape Forum

Raw & Post Processing, Printing => Digital Image Processing => Topic started by: Kirk Gittings on April 14, 2007, 06:35:31 pm

Title: CMYK conversion tool?
Post by: Kirk Gittings 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?
Title: CMYK conversion tool?
Post by: Schewe 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 (http://www.adobe.com/digitalimag/pdfs/phscs2ip_reproprep.pdf) (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.
Title: CMYK conversion tool?
Post by: Kirk Gittings 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.
Title: CMYK conversion tool?
Post by: Schewe on April 15, 2007, 02:54:19 am
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It strikes me that there is much room for improvement.
[{POST_SNAPBACK}][/a] (http://index.php?act=findpost&pid=112458\")

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 (http://homepage.mac.com/WebObjects/FileSharing.woa/wa/Making_Within_the_Stone.pdf.pdf-zip.zip?a=downloadFile&user=billatkinson&path=/Public/Presentations/Making%20Within%20the%20Stone.pdf) (note, it's a 65mb download and doesn't really get into how he did the separations)
Title: CMYK conversion tool?
Post by: Kirk Gittings 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.
Title: CMYK conversion tool?
Post by: Schewe on April 16, 2007, 01:06:26 am
Quote
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...
Title: CMYK conversion tool?
Post by: Kirk Gittings 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.
Title: CMYK conversion tool?
Post by: Schewe on April 16, 2007, 01:43:52 am
Quote
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...
Title: CMYK conversion tool?
Post by: iGuy 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
Title: CMYK conversion tool?
Post by: pfigen 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.
Title: CMYK conversion tool?
Post by: photo570 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.

Cheers
Jason berge
Title: CMYK conversion tool?
Post by: pfigen 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.
Title: CMYK conversion tool?
Post by: Kirk Gittings 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.
Title: CMYK conversion tool?
Post by: pfigen 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.
Title: CMYK conversion tool?
Post by: photo570 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".

 
Title: CMYK conversion tool?
Post by: Kirk Gittings 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.
Title: CMYK conversion tool?
Post by: pfigen 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.
Title: CMYK conversion tool?
Post by: Kirk Gittings 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.
Title: CMYK conversion tool?
Post by: pfigen 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.
Title: CMYK conversion tool?
Post by: Kirk Gittings 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.
Title: CMYK conversion tool?
Post by: pfigen on April 27, 2007, 07:42:53 pm
You then have to decide how much you need to "fix" them. Unless they are hiring you to prepare files for them, I would not worry about anyone else's files and let them print how they print. If the magazine is unhappy with their printing quality and wants help making it better, it is obvious that they could use it, but not til they ask. I've been down that road way too many times. If they don't have a basic understanding of the color management, let alone color corrective, process, unless they're willing to pony up for a company wide retooling, I would not spend too much time with them. Make your own work look as good as possible and when they ask the other works sucks by comparison, you can tell them.

I would also take a test file, something with some known images plus a stepped gray and convert it using their press profile. Look at the total ink numbers. Look at the black plate and how far up the gray ramp the black runs to get a feeling for the k generation in this profile, then Assign the Adobe SWOP profile and see how much your file changes on screen. If the preview stays the same or only changes a little, then you can be reasonably sure that they are at least close to SWOP. If there is a drastic change in appearance, then you have to ask why that is, when the US magazine industry is getting fairly standardized.
Title: CMYK conversion tool?
Post by: Kirk Gittings on April 27, 2007, 10:01:52 pm
You have to demonstrate and set an example if one wants to raise a client to the next level. Like these people who could not even see the issues, and currently they are responsible for about 25% of my income.
Title: CMYK conversion tool?
Post by: pfigen on April 28, 2007, 02:00:08 am
If they are a big client, it probably is in your best interest to improve the situation, but from what you've already said, they aren't too sophisticated, so proceed with caution. It's all too easy to confuse them even more and you'll end up worse than before. Been there before...good luck.
Title: CMYK conversion tool?
Post by: wood on April 28, 2007, 09:50:00 am
Quote
There is a growing need, in my experience, for photographers to do their own CMYK conversions..............Is there broader interest in such a plugin?
[{POST_SNAPBACK}][/a] (http://index.php?act=findpost&pid=112400\")


KIRK,

Take a look at this [a href=\"http://www.craigsactions.com/Products/CActionsProductsMain.html]SITE[/url].
They have some interesting action.

Good Luck,
Wood
Title: CMYK conversion tool?
Post by: Kirk Gittings on April 28, 2007, 12:04:28 pm
Pfigen, I appreciate your experience on this. I am also an educator so I am used to this. I am also teaching a scanning workshop soon that the same art director is attending. So they are up for improving their skills.

Wood, Looks interesting. I will check it out.
Title: CMYK conversion tool?
Post by: fraser.crozier on July 02, 2007, 06:09:19 pm
Quote
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.
[{POST_SNAPBACK}][/a] (http://index.php?act=findpost&pid=114622\")

I would have to say that anyone converting any images to CMYK is misguided. I don't mean this to be deroogatory in any way.

It is in the interest of all users to keep the final Photoshop image at the highest level of abstraction, and allow the ICC conversion to take place in the layout application, or the RIP depending on the output intent.

A very concise guide on file handling can be found at:

[a href=\"http://www.pass4press.com]http://www.pass4press.com[/url]

The days of prepress being the keeper of colour is well and trully past. As in the days where a scanner oeprator was the image processing genius, so too now are the photographers who capture high end digital images.

In a word, "convergence" has seen the gradual erosion of the niche prepress faculty, where there are now sufficient tools and guidelines that mere layout artists can produce a bulletproof PDF with reliable colour management.

The question is, do we stand in the way of progress, or do we assist in the process?
Title: CMYK conversion tool?
Post by: jorgedelfino on July 02, 2007, 06:47:57 pm
I miss the days of just film emulsion numbers and gel filters!

 
Title: CMYK conversion tool?
Post by: bobrobert x on July 11, 2007, 09:21:34 am
Nobody has mentioned the wide gamut cmyk profile listed under free stuff at
curvemeister.com   http://www.curvemeister.com/ (http://www.curvemeister.com/)  Dan Margulis in one of his books recommends something similar
Title: CMYK conversion tool?
Post by: Kirk Gittings on July 25, 2007, 05:39:53 pm
Quote
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...
[a href=\"index.php?act=findpost&pid=112623\"][{POST_SNAPBACK}][/a]

In retrospect, I have to admit that Schewe is/was right. Having some mileage now, going back and forth with the art directors, the printers and their profiles, I have developed a work flow that is predictable, relatively painless, and relatively quick. Basically I just needed some more practice with conversions and some real feedback via my conversions in print. Thanks for the kick in the rear.
Title: CMYK conversion tool?
Post by: digitaldog on July 25, 2007, 05:42:06 pm
Quote
Nobody has mentioned the wide gamut cmyk profile listed under free stuff at
curvemeister.com   http://www.curvemeister.com/ (http://www.curvemeister.com/)  Dan Margulis in one of his books recommends something similar
[a href=\"index.php?act=findpost&pid=127564\"][{POST_SNAPBACK}][/a]

Considering you can't use it to print, what's the point?
Title: CMYK conversion tool?
Post by: Schewe on July 25, 2007, 05:59:49 pm
Quote
In retrospect, I have to admit that Schewe is/was right....snip

snip...Thanks for the kick in the rear.
[a href=\"index.php?act=findpost&pid=129900\"][{POST_SNAPBACK}][/a]


Kirk. . .glad it finally hit home. . .yep, once you get past the point where you question the tools, you then can grok how to use them to your advantage...there's nothing fundimentally wrong with the concept of creating/using a really good CMYK profile, soft proofing so you know how the image will separate, tweaking the image for optimal repro and them doing the separation.

It really does work well. But all the little duckies must be lined up in their rows. Otherwise, you gotta learn to kill off those little duckies who refuse to get into line (kinda like telling an art director to go just in a lake or a printer to do their friggin' job right).

:~)
Title: CMYK conversion tool?
Post by: bobrobert x on July 26, 2007, 03:44:45 am
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Considering you can't use it to print, what's the point?
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The original poster didn't say anything about printing

Quote > 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. <unquote

My reply was in line to his post You are far more knowledgeable than me in this subject but it is generally accepted that there are colour shifts when converting Using this method produces less shifts Dan Margulis - I know that you aren't a fan of his - has a lot of information about it If it does work then it must be an important part of the process of going from RGB to CMYK and ultimately print  
Title: CMYK conversion tool?
Post by: digitaldog on July 26, 2007, 08:41:51 am
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The original poster didn't say anything about printing

CMYK is a print output color space! What else would you do with it?

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it is generally accepted that there are colour shifts when converting

No, its not. There's a remapping of gamut since CMYK is darn small based on the printing device (colorants, inks on press). A color shift is absolutely not accepted nor something that occurs with good ICC profiles for the print device. Bad conversions can result in color shifts, no one wants or expects that. It isn't generally accepted, just the opposite.
Title: CMYK conversion tool?
Post by: Kirk Gittings on July 26, 2007, 10:36:23 am
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The original poster didn't say anything about printing

While that is technically true, web and offset printing was where I was heading with the thread. Having been in this business for 30 years, I have never experienced any other reason to do CMYK conversions. Why else would you do it?
Title: CMYK conversion tool?
Post by: KAP on July 26, 2007, 10:47:15 am
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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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I've no experiance of this software but take a look [a href=\"http://www.binuscan.com/cmyk_prod_multilangues/us/infos_cmyk_prod.html]http://www.binuscan.com/cmyk_prod_multilan..._cmyk_prod.html[/url]

Kevin.
Title: CMYK conversion tool?
Post by: bobrobert x on July 28, 2007, 06:15:29 pm
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CMYK is a print output color space! What else would you do with it?
No, its not. There's a remapping of gamut since CMYK is darn small based on the printing device (colorants, inks on press). A color shift is absolutely not accepted nor something that occurs with good ICC profiles for the print device. Bad conversions can result in color shifts, no one wants or expects that. It isn't generally accepted, just the opposite.
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CMYK is a print output color space! What else would you do with it?
 

I am obviously missing something The photoshop books that I have recommend moving between them for image editing and not just for printing What I have read moving between RGB and CMYK and back means that there is a shift in colours hence the reason for my original post and I mistakenly thought that was the thrust of the original poster's post
Title: CMYK conversion tool?
Post by: LA30 on July 28, 2007, 07:18:51 pm
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CMYK is a print output color space! What else would you do with it?
No, its not. There's a remapping of gamut since CMYK is darn small based on the printing device (colorants, inks on press). A color shift is absolutely not accepted nor something that occurs with good ICC profiles for the print device. Bad conversions can result in color shifts, no one wants or expects that. It isn't generally accepted, just the opposite.
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Thanks Andrew Rodney for chiming in...This thread is ridiculous.

You do CMYK conversions when you are a press operator and you are standing in front of a printing press.  All presses are different and the same one is different day to day.  Make a very nice 16bit RGB file and hand it to a qualified printer and it should come out nice.  My 2 cents.

Ken
Title: CMYK conversion tool?
Post by: digitaldog on July 29, 2007, 10:30:05 am
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I am obviously missing something The photoshop books that I have recommend moving between them for image editing and not just for printing What I have read moving between RGB and CMYK and back means that there is a shift in colours hence the reason for my original post and I mistakenly thought that was the thrust of the original poster's post
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Right, the old move from a useful wide gamut editing space to a device independent output color space to do some turd polishing you could do IN RGB, in less time and with less image damage. I think I have a few of these books too. They probably suggest converting to LAB to sharpen the L channel when you can produce the same results by staying in RGB, running USM and doing a fade luminosity with more control and less damage (faster too).

Go to CMYK last, when your goal is to send those numbers to an output device that requires those CMYK values.
Title: CMYK conversion tool?
Post by: Kirk Gittings on July 29, 2007, 12:50:18 pm
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This thread is ridiculous.


Ken,

Thanks for your smart ass contribution. You may think this thread is ridiculous, but if you do much magazine or book work you would know that CMYK conversions for photographers are a real issue these days. That is why national organizations like ASMP have been doing workshops on it. You can't just
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hand it to a qualified printer and it should come out nice.
, because you oftentimes have no control over which printer it goes to, whether they give a s___, whether the art director at the magazine is going to do a D&D conversion before it even gets to the printer or whether anyone down the road knows what they are doing these days.
Title: CMYK conversion tool?
Post by: digitaldog on July 29, 2007, 01:27:42 pm
Photographers doing their own CMYK conversions is becoming far more common for a number of reasons. I have an article upcoming in Digital Photo Pro about this (techniques and pitfalls). When we used to hand off a transparency, no reason to get involved. But a digital file is a different beast and more and more, photographers are being asked, sometimes demand to provide output ready files when the output device (the actual press) isn't known which is a huge problem. From a technology standpoint, this is all rather easy. The major issues facing us are political.
Title: CMYK conversion tool?
Post by: Kirk Gittings on July 29, 2007, 01:38:04 pm
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The major issues facing us are political.

Absolutely. I look forward to your article.
Title: CMYK conversion tool?
Post by: Schewe on July 29, 2007, 02:48:25 pm
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When we used to hand off a transparency, no reason to get involved.
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Actually, that wasn't my experience in the old days...I used to follow up even after the chrome was sent into production and retouched. The reason was that the prepress people used to heap the horse manure to the client saying the photographer screwed up the chrome by making it unprintable. Prepress had this way of lowering expectations so the first round of proofs, when they looked like crap, could be sent back for "corrections" and more proofs (which they then charged to the client). I would often ask to see the first set of proofs so I could tell the client whether they were getting a hose job. Funny, when the prepress people knew the photographer was going to be checking the first proof, those proofs sure seemed to come out a lot better.

In the late 80's, the PIA (Printing Industries of America) did a survey and found that on average, it took 3.2 proofs before a client would sign off on color. Guess who paid for the extra 2.2 proofs? It was a major source of income for prepress...
Title: CMYK conversion tool?
Post by: digitaldog on July 29, 2007, 03:07:01 pm
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Actually, that wasn't my experience in the old days...I used to follow up even after the chrome was sent into production and retouched. The reason was that the prepress people used to heap the horse manure to the client saying the photographer screwed up the chrome by making it unprintable.

You're just a lot older than me Jeff <g>.

In photo school, we didn't learn to light for repro, that's for sure. When you actually start scanning your own chromes, even on a decent desktop drum, you change your approach a bit in lighting! I certainly hope that anyone that has to shoot film and get that stuff scanned for repro should do the scanning. Its an eye opener.

When's the Pixel Mafia dinner? I'm getting hungry,
Title: CMYK conversion tool?
Post by: bobrobert x on July 30, 2007, 08:07:46 am
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You're just a lot older than me Jeff <g>.

In photo school, we didn't learn to light for repro, that's for sure. When you actually start scanning your own chromes, even on a decent desktop drum, you change your approach a bit in lighting! I certainly hope that anyone that has to shoot film and get that stuff scanned for repro should do the scanning. Its an eye opener.

When's the Pixel Mafia dinner? I'm getting hungry,
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Quote >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. < unquote

The problem with this thread is that - like many others - it got hijacked and posters were posting replies that weren't relevant to the original post and the sniping started Instead of informing the viewers they were ridiculing them without the hint of a bit of humour Not very nice  
Title: CMYK conversion tool?
Post by: LA30 on July 30, 2007, 11:50:11 am
".......Thanks for your smart ass contribution. You may think this thread is ridiculous, but if you do much magazine or book work you would know that CMYK conversions for photographers are a real issue these days. That is why national organizations like ASMP have been doing workshops on it. You can't just
QUOTE
hand it to a qualified printer and it should come out nice.
, because you oftentimes have no control over which printer it goes to, whether they give a s___, whether the art director at the magazine is going to do a D&D conversion before it even gets to the printer or whether anyone down the road knows what they are doing these days."


Dear Kirk,

You are welcome.  In my experience it just takes one person to ruin a file, either it's an art director working off an un-color corrected monitor, a printer operator that doesn't give a s___, or the freelance graphic designer making no money who just doesn't have the time.  My point is that with out getting some pretty specific knowledge of where it will be printed, how large, etc you file might not look so good.  Most of the magazines that I have shot for want everything FTPed to them.  They have me size the files and send them the color corrected rgb file.  I would perfer to give them a large 16bit file.  So far things have looked good, maybe it is the people in my chain that seem to know what they are doing.  

Maybe I should go to a work shop.

Schewe,

"Actually, that wasn't my experience in the old days...I used to follow up even after the chrome was sent into production and retouched. The reason was that the prepress people used to heap the horse manure to the client saying the photographer screwed up the chrome by making it unprintable. Prepress had this way of lowering expectations so the first round of proofs, when they looked like crap, could be sent back for "corrections" and more proofs (which they then charged to the client). I would often ask to see the first set of proofs so I could tell the client whether they were getting a hose job. Funny, when the prepress people knew the photographer was going to be checking the first proof, those proofs sure seemed to come out a lot better.

In the late 80's, the PIA (Printing Industries of America) did a survey and found that on average, it took 3.2 proofs before a client would sign off on color. Guess who paid for the extra 2.2 proofs? It was a major source of income for prepress..."

I have seen this many times, it is almost laughable.


Ken
Title: CMYK conversion tool?
Post by: Kirk Gittings on July 30, 2007, 03:11:24 pm
Ken, the trouble is not your point, but the fact that you think your narrow experience (your "chain" as you call it) is indicative of what is happening in the industry. My "chain", includes a couple of dozen national magazines and presses and the days of "Make a very nice 16bit RGB file and hand it to a qualified printer and it should come out nice." are gone for the most part.