Thank you, but I don't have a Gray menu in CC2015.
And I have in my document other pictures in cmyk...
Any other idea?
Did you read the whole thread? It explains why your image in InDesign may be displayed darker or lighter than in Photoshop.
Yes Peter, I think, but maybe it is my poor english :-)
Do you talk about Overprint/Sep Preview? If yes, it works for the preview. But, when I export in PDF format, the color is darker.
I can't modify pictures, because they are used in other Illustrator files, and I'd rather to not have to duplicate pictures.
The grayscale numbers are transferred to the black plate of the working CMYK profile in the InDesign document. If the dot gain in that profile differs from the gain in the Gray profile assigned to the image it will print either darker or lighter, depending on if the gain is smaller or larger. If it is printing too dark you need to either fix the image, or change the CMYK space, which may not be a good idea if your colors are printing correctly.
There is no other option.
There's also this recent thread:
I import tiff grayscale picture, Dot Gain 15% in Illustrator -> the picture is correct
Illustrator works the same way as InDesign with Overprint turned on. Placed grayscale's gray profiles are ignored and the document's assigned CMYK profile is used to display gray and black percentages. in your case the Illustrator document's CMYK profile happens to display similarly to the 15% Dot gain profile in Photoshop.
If you assign profiles that are not so similar you'll see the change. On the left an illustrator file with US Sheetfed Coated assigned and the original grayscale in Photoshop with 10% Dot gain assigned.
Illustrator and InDesign do not have Gray Working Spaces or CM policies in their Color Settings preferences.
Illustrator works the same way as InDesign with Overprint turned on.
-> yes on screen, but, when I export in PDF format, the grayscale pictures from ID are always darker.
We work with the same pictures on different softwares, with the same ECI profiles, and we just need PDF files (not print).
I can't change pictures and I can't change profiles.
So if I have understood, no real automatic solutions, I have to adapt each times, isn't it?
the grayscale pictures from ID are always darker.
But the actual output values export unchanged, you can check them in AcrobatPro's Separations panel.
The preview in Acrobat or InDesign would depend on how you have the application's color management or Simulation profile setup. If you set AcrobatPro's Simulation profile to 15% Dot Gain, grayscale previews will respond to the profile and match the Photoshop preview. How have you decided that Dot Gain 15% is the correct profile for grayscales?
In Acrobat the Simulation Profile set to Dot Gain 15%–the PS file has Dot Gain 15% assigned.
The Simulation Profile set to the document's Output intent US Sheetfed: