Lightroom conversion to B&W

[Primecath]

I converted 500+ colour jpgs to B&W using Lightroom3, brought pics into InDesign4 and did test run with book printer. He reports pics are in CMYK FORMAT and not B&W which is what we need for this run. How do I get Lightroom3 to make them a B&W picture instead of CMYK or is this and InDesign issue. I am confused.

Also, I am in an incredible RUSH situation - anyone out there that can help with this dilema. Going to take a break now (1:30 EST) but will be back in 1-hour.

Thanks everyone - I know I am new here and asking for rush help is not usually my style but I am in a jam with this one.

Thanks
Catherine

[vomviersen]

Lightroom can't export single channel grayscale files, only variations of RGB.

When we have had this situation (I work in prepress production) we've converted the Lightroom file to a single channel grayscale file in Photoshop.

If the publication is single color black only, you could use the controls in the InDesign print dialog to convert everything to grayscale, print text as black when printing to PDF or to the output device, but I don't know if quality would be adversely affected or not.

[OsmosisStudios]

Not an InDesign issue: you're just putting stuff into it. You'll have to have them saved as greyscales.

[Primecath]

Thank you for your feedback, Vomvierson and Osmostis Studios

In the test, the images are CMYK. Since this book is printing black only the images should be grayscale.

It would be possible to use the test PDF files as supplied. If the images are left in RGB/CMYK our system will convert the images. Based on the default conversion the contrast will be good but the detail in the shadow areas will fill in as that darkest areas of the images will print 100% black.

Above is the report I got from the book printer. If I leave things in their CMYK format they are now in (converted to B&W & tweaked in lightroom so they are lighter and brighter and shadows nice), when they convert to their GRAYSCALE will I loose a lot of detail. They are saying darkest areas will be 100% black -- when I worked on the to B&W conversions I stayed away from either extreme (0 or 100%) in all categories so I think things might turn out well if I let them convert. What do you both think.

As far as converting into GRAYSCALE I guess I would do that in PHOTOSHOP itself -- any advice on settings -- I am new to photoshop.

[vomviersen]

Sounds to me like the printer is saying their default conversion will end up with the photos darker than you intended, in the shadows in particular.

If you have already done the initial conversion to B/W and all of your fixes and tweaks in Lightroom, if you do Image -> Mode -> Grayscale in Photoshop it should just change the file to single channel grayscale with all of your fixes as is.

[Primecath]

Your information was exactly what I needed to read.
Many thanks. Catherine

[ravncat]

I ran into a problem simmilar to this when trying to print BW via lightroom and using epson's advanced black and white printing method - i posted a thread about that here a long time back.

Lightroom and Epson`s ABW

If you are not printing directly from lightroom, Things are a little easier in that you don't have to deal with the difference in gamma. you basically want to convert to greyscale somewhere else, like photoshop.

You can also use a greyscale icc profile for the printer and let the software convert your image from the cmyk colorspace to the greyscale colorspace (even better if it is profiled for a specific paper, and a calibrated monitor) You're post makes me think this isn't an option since someone else is doing the printing.

The only other place to convert to a greyscale profile within lightroom, is via the export tool and color spaces - but you have to find a monochrome colorspace to embed as it wont be a default. You'd select it by choosing other - after finding the necessary icc profile and putting it in whatever defaults folder lightroom uses for those options.

p.s. if they're having issues with darkness of the print - that probably has more to do with the gamma settings involved - my linked post was mostly about dealing with the gamma issue itself.

[Primecath]

Thanks for responding Ravncat. I will look at your link someday soon, however, as you deduced, I am uploading to a print house. Luckily for me, Vomviersen's instructions work. Now I just have to figure out how to do a batch image mode change.

Catherine