black and white conversions

[mikemeister_admin]

Okay, how am I going to do this?
I have been experimenting with the new capabilities of converting color to b&w in LR, which involves either: 1)converting to a grayscale mode and adjusting color, which generally accentuates the noise, and I don't know why:) and 2) desaturating all color sliders in the HSL mode, and then adjusting the luminosity of each slider. In this way, the sky (for example) can be made  darker (and only affects other blue/cyans in the image--which, however, can't be masked out in LR). Number 2 is way less noisy. The whole process is explained in detail here:http://lightroom-news.com/2007/08/24/tips-for-better-black-and-white-conversions/

I thought I could do something similar in CM, by selecting a channel in PS, opening CM, and adjusting the curve of that channel. (which I would have to do for each channel in PS). This would differ from the LR technique of course because I am working on the channels, instead of a color selection. I can do that, but I run into two problems: No masks available to work with, not even the inverted alpha channel. and 2) what exactly am I changing? Both the color and the luminosity, am I not?

I think I'd better pause...has anyone been working in CM with black and white adjustments?



Gloria

[ggroess]

How about a channel mixer layer in PS and setting it to momochrome...

http://www.earthboundlight.com/phototips/black-and-white-photoshop.html

Greg

[mikemeister_admin]

Certainly doable, but I am thinking that since each channel is available in CM, and the curve can be manipulated, is there a way to use one of the masks to create a custom channel that can be used for the final b&w image? Or as part of it? I guess I just answered my own question, but it would involve a lot of trips back and forth from PS to CM the way I am thinking. I feel as though I might be missing something, but I will experiment tonight.
Thanks, Greg.

[ggroess]

Let me know what you find..I kicked it around a bit but I was not able to get the channel blend without the colors showing through.

Greg

[mikemeister_admin]

Well I learned a lot tonight. I used a very colorful image so I would see a lot of difference in the channels. Two of the images I developed in Lightroom, the way Martin Evening described. One I used the grayscale conversion, which involves moving the color sliders. The other I used the HSL sliders: desaturating and then adjusting the luminance sliders for each color. I was trying to make the sky as dark as I could, and make the sunflower in the lower left light with contrast.
The other image I opened in PS. I selected the red channel and opened in CM. I adjusted the curve to try to meet my objectives--a little strong, but not nearly as strong as I could have. I don't think you can do this in PS. Then I brought that back into PS. I copied the red channel, selected the first red channel, went to 'apply image' and picked the red copy. I choose multiply at 100%. I then went to 'fade apply image' and backed it off a little.
This entailed a little experimentation, and I have no idea if this was the easiest way to accomplish this result. However, what I found was the two LR images both had problems around the outline of the flowers, they had less contrast/detail in the petals, and I couldn't get the lower left sunflower bright without also brightening the field behind it. I didn't see any noticeable difference in noise between the three images, but Martin Evening's grayscale rendition of the sky showed much more noise.

l don't think you can do this in PS

Well, I guess you can! I never apply curves without an adjustment layer in PS, but I see that's all you need to do. So now CM provides little if any benefit to this process. Rats. There would be a nice benefit if masks could be applied to the curve...




I believe I now can see, (even if I don't understand the mechanism behind this) that using channels (as opposed to what I believe are LR/ACR color selections) for b&w conversion is a superior way to go. I think it makes an argument for somehow enabling the use of masks on the channel to help fine tune them.

[mikemeister_admin]

In the first screenshot, the upper right is LR color, lower left is LR luminance, lower right is CM/PS.

In the second screenshot, the upper is CM, the lower left is color, the lower right is luminance.

[-default]

Interesting conversions there, Gloria.  I haven't put a  lot of thought into using CM to do B&W conversions, but let me think about it a bit.  It would be easy to add a "B & W" button that simply averaged the channels together to get a black and white image.  Then you could use curves and masks behind that to get some dynamite black and white out of it.

It may even be possible, by using the right preview profile, to do this now using Photoshop's soft preview feature.  Hmmmm.

[ggroess]

Please do...

Hey..I'll pay you back some of the money...

$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$$$$$$$$$

You get the rest when B&W is working...lol

Greg

[-default]

Well I'll be darned - it works, you can use curvemeister to do b&w conversions.  It uses soft proofing, so this is only good in Photoshop.

1) dupe the image, set Photoshop's soft proof to Custom, and select "2.2 gamma"
2) start Curvemeister, and make sure the "support soft proof"  option is on (see attached image).  This will give you a monochrome preview image inside of Curvemeister.
3) pick a color space (I used Lab or HSB to begin with) and use curves, with or without masks, to get the image you want.
4) click apply
5) ignore the ugly colors, and convert the final image to 2.2 gamma

AFAIK, this is a new technique, and can be used for other Photoshop operations where you would normally use a de-saturate layer.

[mikemeister_admin]

Holy Cow!
This is absolutely fantastic, Mike.
Front page New York Times!

I knew I could count on your giant intellect to do more than "average the channels together". Yes!

Now I need to go ahead and install CS3 on my machine. (I've been putting that off due to the printing problems associated with it)

But what you're essentially doing is just using everything at Curvemeister's disposal to optimize the file for b&w, while actually being able to preview it, correct? I have never used the convert to 2.2 gamma. Are there any consequences I should be aware of? I would just convert back to my choice of space to match my printing profile?

This is seriously huge...