Grayscale as K only

[texasjoe]

When I convert a color photo to grayscale in Photoshop, it turns it into a CMYK combination that looks like gray, but actually is comprised of four colors.

Is there a way to convert it to a single color (K "black" only) image?

 

[jimoblak]

How are you converting? You should be going to Image menu>Mode>Grayscale.

- - I hope this helps - -
_{(Complain to someone else if it doesn't)}

 

[duncdude]

Photoshop will still display the CMYK values (which would only become relevant if the image was promoted to colour - even when in greyscale mode. it also displays a K only value (to the left)


Kind Regards
Duncan

 

[texasjoe]

Well, maybe it's not a photoshop problem then. The problem is this: When grayscale photos in process color pages are sent from Acrobat to the imagesetter, we get images on all four plates: CMY&K. In the end they look gray, but they are actually a combination of all four colors. If we had grayscale images on the K plate only, with no image on the other three plates then registration would not have to be perfect to get a perfect image.

Maybe this isn't a photoshop issue, maybe it's an InDesign or Acrobat issue?

 

[duncdude]

sounds like a Distiller thing to me


Kind Regards
Duncan

 

[texasjoe]

We don't use Distiller -- we print to Adobe PDF using Acrobat Professional.

 

[duncdude]

I think that still has job options


Kind Regards
Duncan

 

[texasjoe]

Oh yes, lots and lots of options and settings.

I'll post this at the Acrobat forum -- maybe they'll have some suggestions.

Thanks!

Joe

 

[duncdude]

Good luck


Kind Regards
Duncan

 

[singlewahm]

You can fix this in Photoshop. There is a particular color setting you can use where it will convert your black and white images properly, but if you accidently use it on color images they will look like ick. I don't have the settings handy right now, but it has something to do with using GCR instead of UCR. I can send specifics later if interested.

The other thing I do is to set the image to CMYK mode. Then you select the entire canvas and copy. Now go to each of the color channels and delete. Select the black channel and paste. Then change your image to Grayscale mode.

Hope that helps,
Shannon

 

[duncdude]

what !!!???

what does this have to do with Grey Component Replacement or Under Colour Removal ???

as far as i am aware these describe how the black is utilised in a 4-colour image - i don't think it is intended for this at all

please tell me if i am missing the point !


Kind Regards
Duncan

 

[Treedodger]

This is my first post in an attempt to help anyone, so please forgive me if I ask for something to be done that can't be.

Would it be possible to have the image(s) uploaded or link us to them? Maybe we can help if we saw what you started with and how you converted to grayscale.

Roger