Hi Steve,

My wife and I have been working for the past years on producing a cookbook about Northern Laos food.

I produced the bulk of the photographs, some taken as long as 7 years ago on a Sony 717, later the 828, The Canon 20D, then 5d, now 5D Mk11.

Progression in quality. From the 5D onwards, I used RAW, before that jpg. All taken in situ, often badly lit local kitchens, sometimes bamboo huts by oil lamp light. In short, a mixed bag in terms of quality. 

About a year and a half ago, she started doing the layout in InDesign, aiming to have the book printed online via Lulu or Blurb. Lulu indicated sRGB was Ok for their printing process. 

Each of the 350 photographs in the book was processed by me, usually in Lightroom, occasionally in PS CS3. Then exported into jpg sRGB, sized for the final size in the book and 300 ppi, using the LR export function. This helped us reduce the total size of the book in terms of MB, rather then using the original jpg size, sometimes 14 mb each. 

We received a sample copy from the printer, and weren't happy with the print quality, the bind (glue) fell apart rapidly, and the prices had escalated since we first investigated the process. So we decided instead to go to offset print, and print in Thailand, where we live, using a local Bangkok printer who has shown us previously printed books of good quality. 

During our talks yesterday, they reminded us that they prefer to receive it in the inDesign format, but with all photographs in CYMK.

Since I didn't keep my export settings for each image on file, I have two options:

 1. the lazy way, opening each exported (already sized for the book and usually reduced) jpg in PS, resaving it some size in CYMK. Risk, resaving jpg can cause loss of quality.

2. Going back to each original image (still in a LR catalogue, exporting it from LR to PS, opening it, resize to required size for the book, change ppi to 300, export as jpg CYMK.

Because I'd be using the original file (RAW or jpg), tweaked in LR, I'd also have to apply each crop again accurately as chosen in the layout. 

The total amount of work will be a lot more, since she will probably have to re-align each image again in the layout. in InDesign.

My Question: Is step one e.g., open and re-save jpg in CYMK adequate, or would I be better to use step 2 and start from scratch?



Hi Kees -

First, congratulations on your book!

CMYK:  This is a different animal of a color space normally reserved for printing books, magazines, brochures, etc..

It's not even as close to being as simple as "convert to CMYK" and letting it go like that.  Depending on how your system is color managed, your luminance values, gamma settings, etc.. you're probably going to be far off on colors.  In my experience most professional print houses will use something close to these settings:  5000/2/90  Maybe up to 110 on that last setting.  You'll need to run a few test prints (attaching a print chart for you to use (it's sRGB but converting it to CMYK is a good practice.  If you can get all the nuances of this test chart to print properly in CYMK you'll do fine with the rest of your images.)

About your images.  Try to remember a gamut is like a box of crayons.. the bigger the gamut the more crayons and a set number of shades for the crayons.  It is far easier to start with the biggest box of crayons (gamuts such as Adobe98, Prophoto) and then convert down to the smaller gamut (CYMK) as needed, you will lose far less data this way than if converting from sRGB directly to CYMK.. and of course it will depend on the type and quality of image to begin with.

On my "What's New" page:  I recently linked Jeffrey Fried's excellent article regarding jpeg compression (a loss compression) and he gives great visual aid's on different types of images vs. different levels of compression.  Well worth the read.  He did a great job putting it together.

Keep in mind, it is far better to start with a lossless file (RAW, TIFF, PSD) to make a lossless file (CYMK) than a file that loses data as it's compressed and manipulated (jpegs) if your end result is the best CYMK file possible.

I know this isn't what you want to hear.. and it is possible you could get acceptable results with a straight  conversion.. but I remember your work being very good and I wouldn't want any degradation in that level of work.

SO.. profile your monitor.. 5000/2/90..  Then convert your files upon import into CS3/4/5 (LR still doesn't do CYMK) to CMYK color space,  adjust your files, and then save as CYMK files.  I recommend working the sample file I attached, sending it to your printer, and getting your workflow down solid BEFORE working the rest of your images.  Much better to only do this once.

Let me know if you have any issues with your conversions.  It might be worth a trip over for you to work on proper monitors as your Imac monitor just isn't up to the task of solid CYMK, at least in the since of solidifying your workflow.  Do I remember right you have an Eizo external?  Much better choice if you do.  Imac monitors are good for sRGB work at general levels, but not the professional quality conversions you're looking for.

As an aside, I've recently replaced my tried and trusty Viewsonics (after 8-9 years) with NEC's with internal LUT's (this means the limitation of your one LUT video card doesn't matter because these monitors have built in 14 bit hardware LUT's which are much better), upgraded my color puck to a wide gamut capable model, and procured xrites total color checker system.. just for things like what you're doing.  It's a big investment in both time and money and it's more easy to get it wrong, than to get it right.

I hope this helps.


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