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The absolute best way to convert to B&W

PostPosted: Fri Aug 26, 2005 5:49 pm
by Matt. K
There are any number of ways to convert colour to black and white on the computer but nothing beats this simple yet effective way of using Photoshop. I may have posted this technique to a few members in other threads but I think it needs to be shouted out loud and clear for all!
Convert your image to LAB mode...IMAGE/MODE/LAB
then open the channels palette and click on SPLIT CHANNELS
3 seperate windows will open on your screen...just delete the top 2 and that leaves you with the luminosity channel and the best B&W image availabe. Now tweak contrast etc to suit. Note how well this technique displays skin tones.
Please do not send me any money...I don't have time to spend it.

Re: The absolute best way to convert to B&W

PostPosted: Fri Aug 26, 2005 6:00 pm
by Geoff
Matt. K wrote:There are any number of ways to convert colour to black and white on the computer but nothing beats this simple yet effective way of using Photoshop. I may have posted this technique to a few members in other threads but I think it needs to be shouted out loud and clear for all!
Convert your image to LAB mode...IMAGE/MODE/LAB
then open the channels palette and click on SPLIT CHANNELS
3 seperate windows will open on your screen...just delete the top 2 and that leaves you with the luminosity channel and the best B&W image availabe. Now tweak contrast etc to suit. Note how well this technique displays skin tones.
Please do not send me any money...I don't have time to spend it.


I've been using this method for a few weeks since you showed me matt, and I like it a lot. Thanks :)

PostPosted: Fri Aug 26, 2005 6:30 pm
by Glen
Thanks Matt, B&W for dummies (which is me) I have a few shots coming up where I want B&W so thanks in advance :wink:

PostPosted: Fri Aug 26, 2005 6:47 pm
by BBJ
Thanks Matt, u clever fellow, LOL i just tried it and yeh worked a treat.
Thanks mate.
Now i just have to remember it.LOL

PostPosted: Fri Aug 26, 2005 8:09 pm
by marcotrov
Thank you matt, great! Keep the tips rolling on through.
marco

PostPosted: Fri Aug 26, 2005 9:33 pm
by smac
Thanks Matt, worked a treat!

Stuart

PostPosted: Sat Aug 27, 2005 9:38 am
by Alex
Matt,

Thank you very much for this very useful yet simply method to convert to B&W. Just one question. If the lab I will print those B&W pics at requires all files to be in RGB mode and by using this method we converted to the LAB mode, how can I go about it? Do I go back to Mode> RGB?

Regards,

Alex

PostPosted: Sat Aug 27, 2005 11:37 am
by dooda
hmm, will have to try this out, been using adj layers channel mixer and hue saturation.

PostPosted: Sat Aug 27, 2005 2:00 pm
by lejazzcat
Variety being the spice of life,

A recipe i use with Photoshop.

FIRST check your exposure -note what areas are LOST CYMK=0, and what you need to be careful of loosing .
Open the histogram window
Open a seperate info window

NEXT assess your channels . View each one independantly
Which 'color' channel are you most happy with ?
(note: most of the noise tend to end up in the blue)
Reselect RGB

THEN return to the layers window and make a new adjustment layer- select CHANNEL MIXER
Select the monochrome tickbox- it auto starts you with the result of the red channel.
Now, adjust the balance of the RGB sliders to emphasis the 'personalities' that you liked in the channels assessment.

A 'TIP' for the values to use is that they should total 100 for the 3 colors(eg: R+30,G+100,B-30) as a general target . That equals the basic tonality of the original image.
Of course its just a starting point though. Do what you find is working !

Generally avoid the CONSTANT - it tends to block out shadows or blow out highlights

THEN, if you want a perfect B&W, you can add another channel mixer layer and adjust that one specifically for the highlights that were lost in the previous layer adjustment.

The first channel mixer layers brighter highlights will tend to shine through now, so turn it off. Create a new channel mixer layer and make your adjustments on it until you like the highlight detail. Turn the first back on, and youll notice the highlights have blown out again !
Youll need to create a mask to cover those highlights, and thus allow the adjusted highlights layer to come through.
Select the mask that automatically is added to new adjustment layers and use a big soft brush at 50% opacity (black on white) and paint over the highlights and other areas like around the image edge(helps create a nice point of focus in the centre) and you should get a nice finish.

Hope you like the flavours this gives you .

PostPosted: Sat Aug 27, 2005 3:14 pm
by Matt. K
Alex
Yes. Simply convert back to RGB for your printer.

PostPosted: Sat Aug 27, 2005 3:17 pm
by Matt. K
lejazzcat
This was a popular method and I used it quite often....but it gave me so many options that I often lost sight of my starting point! I guess any road that gets us to Casablanca gets us to Casablanca....main thing is to enjoy the trip. :lol:

PostPosted: Sat Aug 27, 2005 4:33 pm
by lejazzcat
Matt. K wrote:lejazzcat
This was a popular method and I used it quite often....but it gave me so many options that I often lost sight of my starting point! I guess any road that gets us to Casablanca gets us to Casablanca....main thing is to enjoy the trip. :lol:


Ahhh.... Casablanca - another great B&W .

Yep - the nice thing with this recipe is that you dont change your original file, and as a PSD you can continue to fix/messup the result at will.
The double channel mixer layer is a killer approach too- you get the best of both worlds. Shadow and highlight detail, and great contrast.

Mind you though Matt- I also tend to find the endless options daunting- photoshop is amazingly deep and wide -its so easy to get lost !
Its auto vs manual i guess . I like em both :D
.

PostPosted: Sat Aug 27, 2005 6:29 pm
by rjlhughes
I'm surprised no one's mentioned sharpening just the lightness layer in LAB with USM. That's mostly how I sharpen portraits.

PostPosted: Sat Aug 27, 2005 6:44 pm
by Matt. K
rjlhughes
I agree. It is a great way to sharpen portraits...as is using the highpass filter for sharpening images that have large areas of pure tone. So many ways to do things. No wonder we get so immersed in our digital photography.

PostPosted: Sat Aug 27, 2005 6:55 pm
by rjlhughes
Matt,

it's the chinese menu syndrome sometimes - too many choices!

PostPosted: Thu Sep 01, 2005 1:34 am
by Grev
Thanks for the tips! :D

PostPosted: Thu Sep 01, 2005 9:31 am
by Greg B
Matt, you uncolour my life.

:lol: :lol:

Great tips from all, thanks

PostPosted: Sun Sep 25, 2005 4:51 pm
by Spooky
Okay, what am I doing wrong?

I change to Lab mode no problem.
When I click on the channels pallate I get four sections showing in the pallete menu;

Lab
Lightness
a
b

I can't see a split channels command anywhere?
Can't see luminosity anywhere?

PostPosted: Sun Sep 25, 2005 5:37 pm
by stubbsy
Split channels is in the drop down menu you get when you click the small triangle at the top of the channels palette (just below the close button for that palette)

Re: The absolute best way to convert to B&W

PostPosted: Sun Sep 25, 2005 5:54 pm
by Manta
Matt. K wrote:Please do not send me any money...I don't have time to spend it.


Geez Matt - you crack me up!! :lol: :lol:

PostPosted: Mon Sep 26, 2005 9:28 pm
by Spooky
Thanks Stubbsy, I got it.

Thanks Matt K for this tip.

Can this b&W process be done in an action? Is there any way of deleting the top two images in an action?

Also notice it changes the file name a fair bit. This could be a problem when trying to do it in batches.