Is "High Quality Display" selected as your Display Performance in InDesign while you are seeing this problem?
ID has no support for grayscale profiles, output is controlled by transferring the gray values to the black plate of the CMYK profile used for output. The image preview saved in Photoshop might be darker of lighter that than the actual output, and the most accurate rendering you will get is to use overprint preview to judge grayscales on screen.
Anyone have ideas of things I could try?
Also, use your InDesign document's CMYK profile as the grayscale profile in Photoshop. To do that open Color Settings in PS, click More Options if it is available, choose Load Gray... from the Working Spaces Gray popup, load your InDesign doc's CMYK profle.
When a CMYK profile has been loaded as a gray profile it will show as the profile with a Black Ink - prefix. From there you can assign or convert images to the black ink profile.
As Peter pointed out you have to have Overprint/Sep Preview turned on for the black ink profile to be used. With it off grayscales are preview as sGray (2.2 gamma) and your document profiles are not used.
Thank you Rob. Using the CMYK profile this way makes a better result in the final print pdf as wel.
It is a little hard to understand that this should be necessary, but obviously it is if InDesign has no support for grayscale profiles.
Thanks again for another helpful tool :-)
but obviously it is if InDesign has no support for grayscale profiles.
Right, ID doesn't have a grayscale space and ignores embedded gray profiles. You can place or export grayscale objects, but you can't make a grayscale swatch or color.
It makes sense to use the pagelayout's CMYK black ink profile in Photoshop, because in the end there can only be one destination—the US SWOP Coated black ink profile is not the same as the 20% Dot gain Photoshop default. The destination press can only have one profile.