Re[2]: [microsound] [OT] PhotoShop RGB->CMYK

[-ED <minused@xxxxxxxxxxxx>]

Hello scott,

There's a chance to make better conversion if you switch between
different profiles. may be even create your own. there's a chance that
"muddy" colors would convert better. but once again - CMYK has many
restrictions and many things cannot be printed in CMYK at all. if
there's something really special you want to print - you may be need
try not 4 colors (CMYK) but more - and add some pantone colors or a
special mixture or something. This might help. CMYK just can't print
EVERYTHING you have in RGB.

Tuesday, August 5, 2003, 4:47:03 PM, you wrote:

>>>does anyone know of a PS plug that coverts RGB->CMYK i.e., a better
>>>algorithm for RGB->CMYK conversion than what is used in PS?

sa> No that I know of.

>>that conversion is dependent on many things, and has many variables all 
>>which can be controlled from within PShop using conversion curves, or ICC 
>>profiles. it really depends what you are tying to accomplish. CMYK for what 
>>press? Web? Offset? What kind of paper? If your conversion is leaving the 
>>colors looking muddy on screen... it is likely that the original image in 
>>RGB contains colors out of gamut... meaning they can never be printed at 
>>all in a CMYK colorspace... there are techniques for "rescuing" certain 
>>things... (using LAB color space for instance) but without knowing the 
>>details... no one can really help you. there is no "formula" for getting it 
>>right in every instance for any image for all conditions. to it's credit 
>>PShop has an incredibly powerful set of tools for making those conversions 
>>possible... in the hands of a knowledgable operator.

sa> Use the info window. once you have converted to cmyk, use the eye dropper 
sa> tool to read the build, the info window will tell you the exact cmyk 
sa> breakdown of every pixel, if you have a pantone cmyk fan then you can try to 
sa> locate a build that matches what you are reading. If you have been doing 
sa> design and production for a long enough period of time, this is less 
sa> important as you start to just know what breakdowns will look like. Also you 
sa> can use the selective color window to then be able to adjust cmyk builds 
sa> globally, ie. you can adjust only the reds, greens, yellows ect... this will 
sa> allow you to de-muddy builds.

sa> So you really have to read the builds and compare to a pantone process fan 
sa> to really see what that build looks like on paper, what you see on screen is 
sa> not really what you get.

sa> Bottom line. there is no simple easy way to just convert and expect to get 
sa> perfect color, way to many vairbles, you could be using a crappy printer 
sa> then there is the issue of dot gain. but I bet for your needs, this is 
sa> probably just a cd sleeve on a typical house sheet, you dont really need to 
sa> worry to much, also your monitor might not be calibarted. I would suggest 
sa> having a match print made.

sa> email me off-list if you need more help.

sa> -scott

sa> _________________________________________________________________
sa> Add photos to your messages with MSN 8. Get 2 months FREE*.  
sa> http://join.msn.com/?page=features/featuredemail

sa> ---------------------------------------------------------------------
sa> To unsubscribe, e-mail: microsound-unsubscribe@xxxxxxxxxxxxx
sa> For additional commands, e-mail: microsound-help@xxxxxxxxxxxxx
sa> website: http://www.microsound.org

-- 
Best regards,
 -ED                            mailto:minused@xxxxxxxxxxxx

------------------------------