Q: What is the best way to convert to grayscale?

debroglie

macrumors 6502a
Original poster
Aug 19, 2004
607
0
Philadelphia, PA
Hey guys

I have to convert the scan of a painting to greyscale for printing. What is the best way to go about this in photoshop. If you could give me examples of what it would look like, that'd be great!

Thanks
Brad

 

mkrishnan

Moderator emeritus
Jan 9, 2004
29,777
12
Grand Rapids, MI, USA
A second way to do it is to choose Enhance->Adjust Color->Remove Color, but this produces visually identical results. Both literally go to grayscale. You can also use the color variations tool in that segment to produce things like sepia tones. Can you say more about what you want to accomplish? Are you just trying to take it to a printing service and you want a large b&w version? Or are you trying to print it at home (in which case I don't even think you gain anything by making the pic b&w)? Or are you trying for an artistic effect?
 

Mr. Anderson

Moderator emeritus
Nov 1, 2001
22,561
0
VA
just a few minutes of playing I got this.

basically you can use the Channel Mixer and click on the monochrome button. But put the file in 16 bit first, gives you more dynamic range. Tweak the image (red +60, green +42, blue +12, overall -2 for this one).

It gives a little more control over what you end up with, but put it back in 8 bit after you're finished the adjustments.

D
 

Attachments

grapes911

Moderator emeritus
Jul 28, 2003
6,995
3
Citizens Bank Park
While I'm thinking about it, you can try filters.
Sketch filters:
Bas Relief
Conte Crayon
Halftone
Photocopy
Reticulation

Not really grayscale, but these might be worth trying.
 

tech4all

macrumors 68040
Jun 13, 2004
3,400
489
NorCal
Also:

Image > Adjustments > Hue and Saturation, then take Saturation down to -100. (or Command + U)

FYI: If you only want one channel, then Image > Mode > Grayscale will do that. The other modes will still have all the channels - RGB, CMYK, etc - but Grayscale will only have one. May make a difference if you take it to a printer or something.
 

HiRez

macrumors 603
Jan 6, 2004
5,835
1,783
Western US
debroglie said:
I have to convert the scan of a painting to greyscale for printing. What is the best way to go about this in photoshop. If you could give me examples of what it would look like, that'd be great!
Try this or this. This one is my favorite because the examples are a photo of a very hot naked chick...er *cough*...I mean uh, "fine art nude". :rolleyes: If you want to get technical, I think the normal formula for converting color to greyscale is 30% red, 59% green, and 11% blue (approximately). This attempts to correct for how the eye unevenly processes different light wavelengths. But your probably going to want to apply custom values to get it how you want. I'd start by converting to L*a*b mode, disable the a* and b* channels, then use Curves or Levels on L to tweak contrast (this is a quick and dirty method but can yield nice results with a minimum of hassle).
 

Lacero

macrumors 604
Jan 20, 2005
6,639
2
I agree. Convert to LAB mode and copy just the L channel to a new grayscale document. Do a curves command on the new file to bring out the contrast or make the image stronger.
 

debroglie

macrumors 6502a
Original poster
Aug 19, 2004
607
0
Philadelphia, PA
mkrishnan said:
A second way to do it is to choose Enhance->Adjust Color->Remove Color, but this produces visually identical results. Both literally go to grayscale. You can also use the color variations tool in that segment to produce things like sepia tones. Can you say more about what you want to accomplish? Are you just trying to take it to a printing service and you want a large b&w version? Or are you trying to print it at home (in which case I don't even think you gain anything by making the pic b&w)? Or are you trying for an artistic effect?
I know the simple way to convert to grayscale in photoshop, but I was wondering if there is an ideal way to do it to preserve the subtlties and nuances of the color version. Is there one technique that produces a more vibrant result? I will be printing this in a college literary magazine, and our budget doesn't allow for it to be color.
 

wrc fan

macrumors 65816
i did this in a few minutes, I just played with the levels and the hue/saturation on individual channels. As you can probably tell, you can come up with an infinite number of variations, you just need to figure out what you want out of the picture.

 

Lacero

macrumors 604
Jan 20, 2005
6,639
2
Here's my version. With printed grayscale images, you need to definitely enhance contrast.
 

debroglie

macrumors 6502a
Original poster
Aug 19, 2004
607
0
Philadelphia, PA
Thanks for the advice everyone! I ended up getting the best results by adjusting the levels in the channel mixer, and then adjusting contrast and brightness.
 
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