View Full Version : Q: What is the best way to convert to grayscale?
debroglie
Apr 5, 2005, 10:40 PM
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
http://img229.exs.cx/img229/6618/browneyeofthestorm3ns.jpg
grapes911
Apr 5, 2005, 10:43 PM
I don't have photoshop on this computer, but its pretty easy.
Image --> Mode--> Grayscale.
mkrishnan
Apr 5, 2005, 10:49 PM
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
Apr 5, 2005, 10:59 PM
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
grapes911
Apr 5, 2005, 11:01 PM
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
Apr 5, 2005, 11:11 PM
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
Apr 6, 2005, 12:16 AM
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 (http://www.outdoorphotographer.com/content/2002/aug/blkandwhite.html) or this (http://www.photo.net/equipment/digital/editing/bwconvert/). This one (http://www.macrumors.com/) 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
Apr 6, 2005, 12:32 AM
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
Apr 6, 2005, 12:32 AM
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
Apr 6, 2005, 12:44 AM
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.
http://img56.exs.cx/img56/3481/untitled21vj.th.jpg (http://img56.exs.cx/my.php?loc=img56&image=untitled21vj.jpg)
Lacero
Apr 6, 2005, 12:52 AM
Here's my version. With printed grayscale images, you need to definitely enhance contrast.
http://www3.telus.net/poojja/browneyeofthestorm3ns.jpg
The Past
Apr 6, 2005, 01:06 AM
I agree. Playing with it is crucial. For instance, here are three options:
debroglie
Apr 6, 2005, 09:14 AM
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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