Changing cmyk photo to pure 100% black

[gordo]

To Kevin-

I wrote that it was the "simplest" way to go from CMYK to grayscale - not necessarily the "best" way. I thought it best to answer the OPs specific question. Going into what could become a complicated description of all the different ways to generate a grayscale from a CMYK image would have added unnecessary complication.

gordon p

[reyhub]

For a quick and easy and most importantly Lossless conversion of an RGB/CMYK photo to Grayscale do the following:

Step 1. Create a copy of your photo
Step 2. Change your photo from RGB/CMYK to "Lab Color" mode
Step 3. Go to Channels and click on Lightness
Step 4. Change your photo from Lab Color to "Grayscale"
Step 5. You will be asked if you want to discard the other channels. Click o.k.

You now have a perfect grayscale photo. Save it using "Save As" in whatever format you require. TIFF or whatever. This is a little known secret trick (among many) that has always existed in Photoshop for Lossless Manipulation of photographs. Enjoy! Reyn Hubbard