Rgb to cmyk

Is there a way to change the color makeup of ads from rgb to cmyk? I was not the creator of these ads for my newspaper but the printer needs me to change them and get rid of the built black. So, I guess I just need to change the black to pure black.

switch to CMYK color, add a Selective Color adjustment layer and change the Blacks

Similar Messages

Need Info on RGB to CMYK

Hi,
I am new to Illustrator (CS5) and not fully comfortable with RGB vs CMYK. For instance, I created a logo for use on the web using Document Color Mode: RGB where my background color in RGB is 0, 0, 130. When I create a Print document using Document Color Mode: CMYK and copy the logo into the print document, it converts that background color to CMYK (C:100, M:98, Y:16 K:18) where the RGB is now (44, 45, 111).
Is there a way to get a closer match to the original RGB color 0, 0, 130? When the specifications for the print advertisement says images must be in CMYK, I hope I am accomplishing this by using the Print Document Color Mode of CMYK vs RGB? I feel somewhat ignorant on utilizing the RGB vs CMYK color modes and if anyone can give me a tip on what techniques they use to get a closer match of colors for RGB to CMYK or vice versa, I would love to hear it.
Thank you,
Keith

Keith,
First, be aware that you have posted to the Photoshop forum, not the Illustrator forum. The general concepts of color and color management are the same across the spectrum of digital imaging. However, its implementation is slightly different from application to application, so you may also want to post your question to the Illlustrator forum.
[EDIT: Brain fart on my part... This is the color management forum, NOT the Photoshop forum, so you are in the right place! (I spend most of my time in the Photoshop forum; I lost track of where I was...)]
That said, you're running up against a general concept: color gamut.
The color you've spec'd in your RGB file (0/0/130 - and we'll assume for now that it's in the sRGB color space) is outside the gamut of every CMYK color space. That means that the RGB color you see can not be reproduced using a mix of the four CMYK process colors (cyan, magenta, yellow, black). When converting to CMYK, the software picks the closest color that is within the gamut of the CMYK space, hence the color shift.
When you're designing for CMYK, it's best to work in soft-proof mode which allows you to see a pretty close approximation of what your colors will look like in the final color output space - in your case, CMYK.
In Photoshop, to turn on soft-proof, go to View > Proof Setup> Custom... and choose the CMYK output space that matches the press conditions you are designing for.
There are books written about this, but hopefully this short answer points you in the right direction.
Message was edited by: Rick McCleary

I can convert almost things multiple times at the same time including CMYK to RGB (or sRGB), but not RGB to CMYK and not brighten/contrast. How?

I can convert almost things multiple times at the same time including CMYK to RGB (or sRGB), but not RGB to CMYK and not brighten/contrast. How?

If you want a relevant answer you may have to elaborate on what you actually mean. Posting screenshots might help, too.
In any case multiple conversions of an image are not advisable in general.

How do I find out if a photo in iPhoto is RGB or CMYK color? How do I change from RGB to CMYK?

How do I find out if a photo in iPhoto is RGB or CMYK color? How do I change from RGB to CMYK?

Open the file with Preview, type Command + i to bring up the Info pane and it's color mode and profile will be listed as shown here:
To change the color mode to CMYK you'll need a 3rd party image editor like Photoshotp or GraphicConverter to do it. Why do you need CMYK?
OT

How can I convert Pdf from RGB to CMYK, keeping font color 100% K while working in Illustrator?

How can I convert Pdf from RGB to CMYK, keeping font color 100% K while working in Illustrator?
When I try to open the document in Illustrator and I convert to CMYK the black font converts to rich black, but to set up for Offset printintg I need the text to be only in Black (100%K).
The original source of the document is a Microsoft Word file, I have converted the Word file to Pdf in order to setup for OFfset Printing.
Thanks

I have tried that way, but the downside is that the fonts are set in gray not in a 100%K, also I have to deal with other fonts that are composites and meant to stay Full Color. I could select text by text and convert to gray but, its a 64 page document and I wouldn't want to make a expensive mistake.

RGB to CMYK problem

I have just started using Photoshop CS3 amending photos and adding text & graphic for printing. The photos start off in RGB but when I get them printed in CMYK they look dark and terrible! Can anyone offer me guidance on how to handle the transition of photos from RGB to CMYK and how to avoid making them darker/destroying the quality?
Thanks!

Are your source RGB files tagged? Are you sure the profile is correct? What's the output CMYK profile? Is your monitor calibrated and profiled?
If you have a good source profile on the files, and you know the CMYK target profile, you should do the RGB-CMYK conversion in Photoshop yourself, then tweak the colors using softproof. (Make sure you save the CMYK conversions and edits as SEPARATE files - don't save them over your source RGB files!)
The resulting files should reproduce much better on the press. If not, chances are good the printer isn't honoring your embedded profile or is doing another CMYK conversion without telling you.

Rgb to cmyk turns white brown

Hi Guys
In previous versions - changing from RGB to CMYK or vice versa would change the colours slightly but ever since CC when I change one to the other my white
goes brown and there is a yellow tone to the image.
Has anyone else experienced this - it's not slight either see image. I haven't adjusted anything - the original CMYK is on the left and
when I make it RGB - it goes brown.
Has anyone else had this issue?

I'd try a new display profile first. Recalibrate, or if you don't have a calibrator use sRGB (or Adobe RGB if your display is wide gamut).
Everything in Photoshop passes through the display profile. If there's a problem with the profile it can happen that one conversion goes bad but not another.
On Windows a common cause for this is bogus manufacturer profiles pushed through Windows Update. Mac isn't as susceptible to this, but there you have an added complication called ColorSync (which is where the actual profile conversions are done). So if a new profile doesn't fix it, you probably need someone with Mac OS X expertise.

RGB to CMYK gives me a white glaze? how to get rid of it

In photoshop cs5 when i convert an image i am working on from RGB to CMYK i get a white glaze over the image? as if i have added a photo filter or something? do you know how to prevent this on a mac computer?

Apple Custard Studios wrote:
…yes i can see that it is broke, but if you look in your last post the before image is in there for some reason, and the after picture is at the top in the earlier discussions.
Sorry, I don't understand what you're trying to say here. How can the "before" image be in any post of mine if I have never been able to see it?
The image I posted in my post, was your "after" image CORRECTED by me as explained in that post:
"Converting it to sRGB and setting the black and white points via a quick Auto Levels adjustment, brings about an improvement."
In other words, I downloaded your "after" image, opened in Photoshop, went to the Edit menu and used Convert To Profile to convert it to the sRGB color space, then I ran and Auto Levels adjustment. That's how I fixed your mess.
Apple Custard Studios wrote:
Hi station_two
…When i convert from rgb to cmyk, i SIMPLY GO: Image > mode> then click cmyk?…
Geebus Chrysler! No, that is indeed not just "primitive" but totally wrong. Go to the CONVERT TO PROFILE menu item in the Edit menu in Photoshop, and from that menu select the specific CMYK profile you want (or your printer requests). Be careful to select CONVERT TO PROFILE, do not under any circumstances choose "Assign Profile"! Converting to the appropriate CMYK profile will also automatically change the image mode to CMYK mode.
Apple Custard Studios wrote:
…which i am unsure it it may mean i have wrong profiles set, but if so what would i need to change it to?…
Apple Custard, it's obvious that you have no clue as to what Color Management is, and teaching you Color Management step by step here exceeds the scope of what can be accomplished in a forum. A good place to start reading up on it is here:
http://www.gballard.net/psd/cmstheory.html
In a nutshell: Your Monitor profile should be the file resulting from your calibrating and profiling your monitor with a hardware calibrator puck. Calibrate and profile your monitor regularly and often. Your monitor profile thus will be device-dependent, specific to your monitor.
Your working space, on the other hand, should be a device-independent profile, such as Adobe RGB or sRGB. It should NEVER, ever be your monitor profile.
Your target profile when printing should be device-dependent and specific to the combination of ink, paper and printer model you'll be using. For the web, create a copy of your image file and convert it to sRGB, then save it as a JPEG as needed.
Good luck!

RGB to CMYK (channels) with PixelConduit plugin

As I'm unable to submit a user tip yet, I thought I'd share my solution here for anyone looking to simulate CMYK channels in Motion/FCPX.
PROBLEM
For some reason you want to convert your RGB source clip to extract individual CMYK (Cyan, Mangenta, Yellow, blacK) channels. For example you'd want to simulate the printing process of a book on a printing press.
SOLUTION
Use a free FCPX/Motion 5 plugin caled PixelConduit, a node-based visual effects design system. Install the plugin before launching Motion.
To extract CMYK channels, I used a (linear) RGB to CMYK formula:
Black   = Math.min( 1 - Red, 1 - Green, 1 - Blue )
Cyan    = ( ( 1 - Red )   - Black ) / ( 1 - Black )
Magenta = ( ( 1 - Green ) - Black ) / ( 1 - Black )
Yellow = ( ( 1 - Blue ) - Black ) / ( 1 - Black )
and translated it to PixelConduit's nodes.
Clone your source clip four times. Call the clones 'Cyan', 'Magenta', 'Yellow' and 'Black'. Navigate to Library > Filters > Conduit Effect System, choose Conduit and apply it to each clone layer. In Inspector, click 'Show Conduit Editor' and assemble the following node tree for each layer:
K (black) layer:
C (cyan), M (magenta) and Y (yellow) layers are identical except the first channel selection:
So, for M and Y layers change the 'Separate RGBA' node to output the green and blue channel respectively. You can copy/paste the whole node tree between intances of the filter so you don't have to create everything again from scratch.
You should now have four layers outputting a simulation of C, M, Y and K channel in greyscale. If you'd like to present these channels in colour you'd need to add Colorize filter to each clone layer:
And finally, if you use Multiply Blend Mode for each clone layer group you'll get a pretty close colour composition to the original source clip! By fine-tuning colour values in Colorize filters and/or tone curves in Conduit you could probably get a perfect conversion.
Colour values used in Colorize filter:
Remap White To:
1, 1, 1 (all)
Remap Black To:
0, 0.61, 0.89 (cyan)
1, 0, 0.5 (magenta)
1, 0.95, 0 (yellow)
0, 0, 0 (black)
That's it! Hope it can help anyone :^)

As I'm unable to submit a user tip yet, I thought I'd share my solution here for anyone looking to simulate CMYK channels in Motion/FCPX.
PROBLEM
For some reason you want to convert your RGB source clip to extract individual CMYK (Cyan, Mangenta, Yellow, blacK) channels. For example you'd want to simulate the printing process of a book on a printing press.
SOLUTION
Use a free FCPX/Motion 5 plugin caled PixelConduit, a node-based visual effects design system. Install the plugin before launching Motion.
To extract CMYK channels, I used a (linear) RGB to CMYK formula:
Black   = Math.min( 1 - Red, 1 - Green, 1 - Blue )
Cyan    = ( ( 1 - Red )   - Black ) / ( 1 - Black )
Magenta = ( ( 1 - Green ) - Black ) / ( 1 - Black )
Yellow = ( ( 1 - Blue ) - Black ) / ( 1 - Black )
and translated it to PixelConduit's nodes.
Clone your source clip four times. Call the clones 'Cyan', 'Magenta', 'Yellow' and 'Black'. Navigate to Library > Filters > Conduit Effect System, choose Conduit and apply it to each clone layer. In Inspector, click 'Show Conduit Editor' and assemble the following node tree for each layer:
K (black) layer:
C (cyan), M (magenta) and Y (yellow) layers are identical except the first channel selection:
So, for M and Y layers change the 'Separate RGBA' node to output the green and blue channel respectively. You can copy/paste the whole node tree between intances of the filter so you don't have to create everything again from scratch.
You should now have four layers outputting a simulation of C, M, Y and K channel in greyscale. If you'd like to present these channels in colour you'd need to add Colorize filter to each clone layer:
And finally, if you use Multiply Blend Mode for each clone layer group you'll get a pretty close colour composition to the original source clip! By fine-tuning colour values in Colorize filters and/or tone curves in Conduit you could probably get a perfect conversion.
Colour values used in Colorize filter:
Remap White To:
1, 1, 1 (all)
Remap Black To:
0, 0.61, 0.89 (cyan)
1, 0, 0.5 (magenta)
1, 0.95, 0 (yellow)
0, 0, 0 (black)
That's it! Hope it can help anyone :^)

RGB to CMYK to commercial printer

We are using CS2 InDesign and Photoshop 7 on a PC. I am putting together two
large books. One insert section of the first book has color photos. I have
to prepare these color photos for a printer located in China. They want all
images to be CMYK .tiff.
I have an assortment of about 100 images from various sources around the
world, there are .tif, .jpg. .bmp, and .psd. All of them appear to be RGB.
There are images with: 1) no color profile, 2) sRGB IE60966-2.1, and Adobe
RGB 1998. Do all images need to have the same RGB color profile before
converting to CMYK?
I have been converting all of these to .tif (and using a single dpi/pixel
resolution for
all images).
Do I just select/save as color mode CMYK? Or are there special
settings/profiles I need to know about. Is there anything special for China?
The printer's English is not that clear . I was hoping that someone in this
group would be familiar with RGB to CMYK conversion.
Also, it appears that the final PDF pages (with embedded Tiff images) will
be very large. The first complete book for this project (there are two
books) looks like it will be about 20GB. The second book looks like it could
be 12GB. Both books together equal about 1,000 pages and have about 1,000
images. 90% of the images are grayscale. What are the current technologies
for sending large projects like this to a printer?
Thanks
ps, the Photoshop group suggested that I write to this group.

Tech....
In the conversions, are you referring to conversions of B&W or color images? I'll assume color for the moment.
Assuming your monitor is properly calibrated, and assuming you are viewing your color images on your monitor, your conversions should keep "in gamut" colors the same. You will, however, probably see some loss of dynamic range, color, and saturation as you enter CMYK. If the color and dynamic range of the original is all within the destination CMYK gamut, you should see very little, if any, shift. The sad fact is that CMYK on press has limited dynamic range and color, especially compared to a bright monitor. This is generally true, though CMYK can print some colors that lie outside the typical monitor's gamut.
If you have a brightly colored original in RGB mode, then you should experiment with both perceptual and relative colorimetric rendering to see which one looks best. This is an image by image thing. Relative colorimetric will reproduce all "in gamut colors" as accurately as possible, then will take out of gamut colors and bring them to the closest printable color. This can cause loss of detail and 'piling up of colors' as you near the boundaries of the image's color gamut in the destination CMYK space. Perceptual scales ALL colors and preserves the relationships between colors, which sacrifices color accuracy and saturation, but sometimes looks more natural, especially if there are a LOT of out of gamut colors. Pick whichever ones looks best overall.
Then, once in CMYK, make minor curves adjustments to tweak if for CMYK. Just be careful not to push it too far, especially in the deep shadows, since you may push beyond the ink limit of the press. For example, if you convert to US Web Coated SWOP v2, the ink limits are set at 300 total. If you drastically darken the shadow areas, you could end up with an ink limit of 320, 330, 350, etc. Knowing the ink limit of the press will help you stay within those limits. Final tweaking in CMYK is usually a good thing.
How did you determine that the images were dull with too much magenta? Did you print a proof on a calibrated printer, or is this just your screen display? Or is this from a printed image off the press? I have a well calibrated monitor and accurate custom profiles for my inkjet. If I am sending a job to a press that supposedly prints to US Web Coated SWOP, I can proof that file on my inkjet and get a very good match. We need more information to know exactly what you are doing and how you are assessing your images.
Normally, I do the conversion in Photoshop, using the rendering intent that looks best. Then I tweak the image in CMYK to get it looking its best. I usually have the press profile, but sometimes work with a standard profile if no custom profile is available. I leave the image tagged with my conversion profile. Then, I usually place these images into InDesign, with the profile intact (color management turned on in InDesign). I right click on the placed image to be sure that the profile and rendering intent are set to what I want. Then, I can either supply the InDesign file to the printer, or convert to PDF (leave color unchanged) and make sure that all profiles are included. InDesign should export each image to the PDF properly, along with profile and intent. I have never sent to job to press using Photoshop...only InDesign or Illustrator.
BTW, rendering intent is only used when getting an image from one color space to another, such as a conversion from RGB to CMYK. You do that, choosing the one that looks the best. Once it is in the destination CMYK space, rendering intent is no longer needed, since all the colors and tones have already been remapped into the final space. Rendering intent is just used to help us handle those out of gamut colors.
Hope this helps.
Lou

How can you tell if a PDF is RGB or CMYK?

From the screeshto below I am finding the only way to tell if a PDF I receive is RGB or CMYK, is by the transparency blending space. Are there any other ways?
The drop shadow on the chip is showing cyan, along with the yellow arrow. The original files do not have cyan in these areas. Is this because the PDF is being saved as smallest file size, which converts CMYK to RGB, then in Acrobat we are coverting RGB values back to CMYK, and with those color conversions you cannot proof Smllest file size PDFs for CMYK breakdowns.
What are others using out there in proffing PDFs for color, smallest file size with color conversion set to no? Doing that makes our PDFs about 150% to 200% larger and they often wont fit in email then. Are there any secret ways of proofing a standard smallest file size PDFs for accurate CMYK breakdowns?

In Acrobat Pro 9:
Advanced Menu to Preflight
Upper Right corner of Preflight dialog box click on "Options"
then select "Create Inventory"
deselect everything except colors and click "OK"
it will analyze your document and return with the number of "plates" as well as the names of the plates...

How to make a script to convert RGB to CMYK as black 100%?

Hi guy
my customer sent me a book (144 pages) for print but all of them are RGB and Tiff, she scan them. there are on the page some texts and pictures. The text are R=30 G=30 B=30.I think if I can make a script I will do it very soon to black 100%, but unfortunately I dont know anything to make script
anybody can help me ?anybody can make it for me ?

We need to know some more information.
1. The book consists of 144 pages, and each page is in fact an RGB image in TIFF format.
    Correct?
    That means, the text is already rasterized, but with low resolution (no more than 300ppi).
    A very bad starting point, in my humble opinion. For offset printing this is not acceptable.
2. Is the printing process offset printing or by digital printing?
Nevertheless we may think about a conversion of these images into CMYK K-only (one plate
per page) .
a) Increase contrast until R=G=B=0 for text.
b) Convert each image into Grayscale, using a so-called Black-Ink-Profile, for instance
    Black-Ink-ISOCoated-v2-eci (can be explained later)
c) Make empty CMYK image, here for ISOCoated-v2-eci, and paste the Grayscale into the
    K-channel. All further handling happens as CMYK file for the process ISOCoated-v2-eci.
    Void plates CMY don't matter.
    Post #12 here:
    Re: Colour shift (from CMYK = 0 0 0 20 to Grayscale K = 22 !)
All this can be done by an action (I hope so...).
Much better would be a new start by InDesign with typographical text (K-only vector instead of raster)
with images in RGB or CMYK, taking into account the intended process.
Note: Photoshop can deliver vector text, if exported as PDF.
Best regards --Gernot Hoffmann

Problem when converting RGB to CMYK in illustrator CC

Today I realized I had my document in RBG mode rather than CMYK. I am drawing die lines over a CMYK TIFF file placed in the document. When I try to convert my illustrator document color mode from RGB to CMYK everything in the document goes white - including the CMYK TIFF file that I have placed in it.
I can highlight the paths and see them only when they are highlighted but Illustrator will not allow me to select a new color for them.
In older versions of Illustrator I have had it would seamlessly convert to CMYK without changing everything to white.
I tried creating a new document with CMYK color mode and pasting the items in and it still goes all white.
In illustrator CS3 it converts just fine from RGB to CMYK with no image loss and no color loss on my dieline paths. but because my version of CS3 is acting crazy it won't allow me to save files from it
any help appreciated!!
thank you so much

hi monika!
no they are just plain old paths in black. and the TIFF file is just a regular TIFF file that is being placed on the bottom layer.
thanks for any help!!

Why does Illustrator automatically change RGB and CMYK values

Hi, I am struggling to understand why Illustrator is changing the values inside the RGB and CMYK boxes. I am also not sure of the exact relationship between these values. Essentially, it appears that if you set the Document Color Mode to RGB, it leaves the RGB values that you type in alone. If you set the Document Color Mode to CMYK, it leaves the CMYK values alone.
But as soon as you change the Color Mode, it automatically modifies the values. So if you were in RGB mode and you set some RGB values, it changes those RGB values when you switch to CMYK mode. And vice versa.
I had thought that the CMYK palette was a subset of the RGB palette. It would make sense to me if it did this when I switched from RGB to CMYK mode, but it doesn't make sense to me why it does this when I switch from CMYK to RGB mode.
The other thing I am confused about is the relationship of the values in the RGB boxes to the values in the CMYK boxes. I would have thought that the relationship between them would be static. Actually, it is not. When I am in CMYK mode and I enter a CMYK value of 90 16 0 0, the RGB values become 0 158 222. But when I switch over to RGB mode, the RGB values of 0 158 222 result in CMYK values of 75 23 0 0.
Very confusing.
Thanks in advance if you can explain this behavior!
Best Regards,
Z.

Color management.
Hi, I am struggling to understand why Illustrator is changing the values inside the RGB and CMYK boxes. I am also not sure of the exact relationship between these values. Essentially, it appears that if you set the Document Color Mode to RGB, it leaves the RGB values that you type in alone. If you set the Document Color Mode to CMYK, it leaves the CMYK values alone.
An Ai document can be either RGB or CMYK. The colors follow the document color mode and thus are converted immediately if they don't match.
But as soon as you change the Color Mode, it automatically modifies the values. So if you were in RGB mode and you set some RGB values, it changes those RGB values when you switch to CMYK mode. And vice versa.
Same reason.
I had thought that the CMYK palette was a subset of the RGB palette. It would make sense to me if it did this when I switched from RGB to CMYK mode, but it doesn't make sense to me why it does this when I switch from CMYK to RGB mode.
It's not. CMYK color spaces (there are more than just one) are normally smaller than RGB color spaces, but they aren't a "subset".
The other thing I am confused about is the relationship of the values in the RGB boxes to the values in the CMYK boxes. I would have thought that the relationship between them would be static. Actually, it is not. When I am in CMYK mode and I enter a CMYK value of 90 16 0 0, the RGB values become 0 158 222. But when I switch over to RGB mode, the RGB values of 0 158 222 result in CMYK values of 75 23 0 0.
When Illustrator converts the colors, it uses color management: the profiles you set up and the methods you set up. After converting it forgets the color that used to be. When converting "back", it uses color management again.
When you convert an very bright RGB color, it be out of the CMYK gamut. So it get's converted to the closest possbile CMYK color (which might still be far away from the original color. But it's not possible to convert it "back" to the bright one unless you just revert the conversion (by Cmd/Ctrl + Z).

RGB or CMYK colour formatting for iPhoto Albums printing.

Hi.
I'm putting my first iPhoto Album together. Info given from Apple about what colour format to use for your photos, says to use RGB. While this is corrcet for digital monitors and screens. Mass printing uses CMYK. Any images supplied to a printers in RGB will colour shift when printed in CMYK. No matter what a printer tells you, these colour shifts can be very noticable. I'm an Advertsing Art Director and I've seen the shift that happens.
I will be checking/colour correting all photos submitted to the iPhoto Album with Adobe Photoshop. And many will very probably undergo some corrections. Be it through levels, curves, hue/saturation, etc. Nothing to anything near an excessive level, but enough to make obvious improvements.
So I will then be faced with the choice of whether to save the images out in RGB or CMYK.
Can someone with some technique knowledge, from the iPhoto team, tell me/reasure me why RGB has been specified? And if CMYK wouldn't actually be a preferable colour format to supply in, considering you'll be printing them in CMYK.
Many Thanks, Jim.

You're absolutely correct. I was referring to notes make a number of years ago in regards to iPhoto 5 and that RGB was recommended for both books and prints.
I was confusing CMYK with Grayscale with Dot Gain 20% profile when stating iPhoto didn't support it which it didn't fully support until iPhoto 9.
In fact I just ran a test with iPhoto 6, 7 and 8 with a CMYK AND GrayScale files with the following results:
iPhoto 6 (06): wouldn't import CMYK but did GrayScale. The grayscale file would only display as a black thumbnail and negative full image. If the DotGain 20% profile was stipped from it the iamge would dispaly normally.
iPhoto 7 (08): wouldn't import CMYK but did GrayScale. The grayscale file would only display as a black thumbnail and negative full image. If the DotGain 20% profile was stipped from it the iamge would dispaly normally.
iPhoto 8 (09): neither file would import which is surprising:
iPhoto 9.2.3 (11): both imported and viewed normally.
iPhoto 9.4 (11): both imported and viewed normally.
In Oct, 2007 I got an email from Apple support with the following:
Also as iphoto makes a pdf of the book and then uploads it to keep the size down, it doesn't matter if the pics are RGB or CMYK as a pdf is a closed file. But since it is going through prinergy it has an RGB checker so this most be switched off. It is how the software in prinergy handle's it that causes the washed out affect as it takes the Red Green Blue colours and tries to convert to Cyan Magenta Yellow Black. Now the colour spectrum in printing between rgb and cmyk is quite different looking at a colour wheel will show you. The best way i can describe it is if you have a pantone book which has spot on one side and process on the other you can see a colour difference. Or if you use quark open up the colours and again switch between process and spot.
BUT ONLY CONVERT PICS TO CMYK IF YOU ONLY INTEND TO ORDER BOOKS. IF YOU INTEND TO ORDER PRINTS IT WILL NEED TO BE RGB.
Here's how i see it:
1. Apple doesn't want 2 different versions of the pics floating about as running CMYK through a photomachine (as prints you would order in the high street) will not print correctly.
2. RGb's going through a CMYK press using prinergy will attempt to convert and produce the washed out effect, or yellowing effect BUT will still print.
So it will use the 2nd option as it will still produce prints normally and books with a slightly washed out effect. Now to most people in the high street, who will notice a difference?
I have just received my latest book saved as CMYK pics in tiff format and no washed out effect. What i will say is The quality if still not as good as a print. Now we use a docucolour 5252 at work and the colour quality is better. I wonder how often the machine is calibrated and what colour curve it is set to?
However, I am unable to import a CMYK file in any iPhoto version until iPhoto 9. Go figure.
Thanks for the feedback. Hadn't addressed this particular subject in quite a long time.

Rgb to cmyk

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