Advanced' Photography Forums

Hi, all,

Need a little help here. Recently, when I use the PS/3 B&W tool, it seems to me that my pictures have a faint sepia tint to them. I can't tell if it's just a trick of my eyes or not, but they don't look *true* black and white. I've looked at some of my shots on other sites that I've posted, and I think I see the same phenomenon.

Here's a shot that seems slightly sepia to me:

So, I went to color balance and increased the Cyan and Magentas to rectify and this looks better to me.

Am I going crazy ? Could my monitor be displaying incorrectly ? I checked the color balance of it (it's an Acer) and red, blue and yellow are all at 50, so that *seems* to be okay.

Is it me, or is it in my head or is my monitor ?

madame_ava said 2 years ago 11/17/2009 3:23:19 PM EDT

The first one def looks black and white to me. The second has a blue tint.

Can you look at it on a different monitor?

I don't know if this will help you or not, but the first I took a sample of the sky and it was in the red spectrum - #B6B6B6

The second was in the blue spectrum - #A9B0BA

So not really sepia but toward the red. The second is toward the blue. I like the first better.

It depends on whoch monitor I loo kat hte pics. On my notebook the first one looks slightly sepia and the second one B&W. On my main monitor the first one is B&W and the second bluish.

B6 for all channels, isn't that flat grey?

The first one is gray on my screen (calibrated with Spyder2Pro), the second one blue. I agree with northman, and adijsieker, for that matter. It doesn't get much gray-er than B6.


You said you checked the color balance of your screen, but have you actually calibrated it?
If you haven't, then the color balance doesn't really mean anything.


If you want to be completely sure, make it black and white with the PS3/B&W tool. If it's good to your liking, convert to grayscale (Image -> Mode -> Grayscale) and see what happens, because then it is "really" black and white.

SigloV said 2 years ago 11/17/2009 5:12:11 PM EDT

+ in reply to...  

Yes - If all three RGB values are equal then it is grey.

The first one looks slightly red and the second slightly blue. I am on my lap top so this could be different on an lcd or crt.
I found these two sites that might help.
http://epaperpress.com/monitorcal/
http://www.normankoren.com/makingfineprints.html
I got a good tip from the team tourney. Don't remember who from.
to convert to B&W I now use channel mixer and select monochrome
This gives better results and I think better control.

SigloV said 2 years ago 11/17/2009 5:44:59 PM EDT

Desaturation, channel mixer or B&W tool will all give you a "true" B&W conversion.

Each method will ensure that the RGB channel values are equal for each pixel in the image.

If you are seeing a colour cast then it is because your monitor has not been correctly calibrated.

Does anyone have any recommendations for calibration sites, preferably free ?

And, thank you everyone, for your comments.

No, there is a slider at the bottom of the B&W tool for adding a tint to the image.

Are we sure the OP knows exactly what the tool is doing? It may be he is getting confused and using the bottom sliders as well.

I have checked your second image and it has a consistent blue tint, that is it has been converted to pure B&W then given a slight blue tint. In the B&W conversion dialog there is a checkbox at the bottom for 'tint' followed by sliders for hue and saturation, these are for adding a tint to the image after it has been converted to B&W. It is possible that you were adding a tint to the image in order to try and counteract the tint of your monitor.

Any which way, uncheck the 'tint' box for a pure greyscale image (but most images actually benefit from a bit of tinting).

By the way, I do quite a lot of B&W work and I find the channel mixer the worst possible way to do these conversions. My favourite is a color wheel but standard PS does not include this. I do consider the B&W conversion dialog to be better than the channel mixer thougth, sometimes being more difficult to use does not mean that it is better ;-)

madame_ava said 2 years ago 11/18/2009 11:29:50 AM EDT

Why?

Find, on your system, Adobe Gamma.

On Windows XP it's in the control pannel, duno where on a Mac but a search should find it.

You can use it to visually zero in your monitor to neutral. It's all I've ever used on my system for color calibration and combined with a little bit of knowledge on "the numbers" of color (RGB, CMYK, and LAB) it can get you close enough for 99.9 percent of your work.

it's pretty straightforward too, but ask here if you have any questions.

I used to have the same problem on my system, before running it. True neutrals would look sepia.

I am also curious why you don't like to use this method.

OK, before I talk about why I don't like the channel mixer, let's talk about why I like the color wheel....what is the color wheel. Here it is in action:

I guess the reason I like it is that it is a direct relationship to real B&W filters, as you move that marker around the wheel with the mouse you can select any shade of filter in any strength. The color you are selecting under the cursor turns up lighter in the image, the opposite color on the wheel get's darker. Very easy, very intuitive, and like I said, works just like a real filter.

Now, let's talk about the channel mixer. Of course it is not a specific B&W conversion tool, in fact it is a very general purpose tool that allows you to vary the relative intensity of the red, blue and green pixels, and feed the output into different channels on the output. You can do a lot of things with channel mixer, for example change the colors of things. But you can also feed the output into a single greyscale output for B&W conversions. That way by varying the relative mix of the R, G & B layers you can simulate the effect of a B&W filter. But it is not particularly intuitive, moving from one hue to another can mean individually adjusting 3 sliders and a bit of guesswork. A lot of faffing around and with no real feedback about the specific filter shade you are simulating. But then again, we can't really complain, after all it is a general purpose tool.

Adobe do not have a color wheel converter built in, though I am sure you could probably find it as an add in. However they do seemed to have realized how poor the channel mixer is for B&W work and added a similar more specific tool, hte B&W tool. This essentially works the same way as the channel mixer with the output set to greyscale (as it is when you check the monochrome box). However it doubles the number of channels to add the complementary Cyan, Magneta, and Yellow. And it lays them out logically, the first three channels are Red, Yellow and Green. This is the arc of the color wheel which is mostly used for B&W filters, the other side of wheel is generally only useful for misty shots. More importantly you have a specific control for the yellow which you can then pull into the orange or lime green, this is really where you work most (leastways I do, but yellow filters were also the most common 'real' filters so I guess it is pretty commonplace). Now of course you can do yellow filters with the channel mixer, but you have to juggle the sliders a lot more.

Oh, and as an added bonus the B&W tool throws in an option to tint the image, and although you could do that elsewhere it is nice to have it on the same dialog because you can see the effects of the filtering in the final form.

So while I like the color wheel best, the B&W tool has the advantage of being built into PS, and it can be used as an adjustment layer (tip: using adjustment layers you can also vary the color saturations, vibrance and histograms on the underlying image).

So, why do people like using the inferior channel mixer? :D

(I think the real answer is because the channel mixer has been around scince the early days, whilst the B&W tool is a relatively new edition. Also when it first appeared I seem to remeber that is was not available as an adjustment layer. So I guess it is just tradition!).

Ok, thanks for the explanation. I only have CS, so channel mixer it is. :)

So which version of PS added the B&W tool, and when did it become available as an adjustment layer?

I know it is in CS4, and I remember it being in an earlier version but not as an adjustment layer....but I can't remember which!

B&W was a CS3 addition.

a great way to use a color wheel esque option is to put a black to white gradient map overtop of the original layer. then, sandwiched between the original color layer and the gradient that turns it B+W you put a Hue/Saturation adjustment layer

then as you drag the Hue slider across the spectrum you'll see the changes in contrast and tone as interpreted in black and white. It's a great way to dial in the "filter" as ercolano would say.

Oh, that's a neat DIY color wheel... thanks CP!

or what about putting a curves layer in there instead of Hue/Sat?

that can be fun too.

Possabilities = Endless