Selective color in black and white photos

[anonymous]

I have been taking photographs for many years now using medium format camera's. Now that the digital camera is the way forward l am slowly being converted. I have spent many hours playing with Abobe Photoshop and produce some stunning work, but the one effect that l would love to be able to produce is to convert a color photograph into black & white, while also retaining certain portions of the picture in color. Any tips or pointers in the right direction l would be great.

[McQ]

All methods I am aware of require creating two layers in photoshop: one as the desired black and white image (on top) and the other as the original colour photo.

The tricky part is that you then need to create a layer mask between the two so that you can have parts of the color image selectively pass through the mask and become visible. Creating the mask can vary from straightforward to very time consuming, depending on subject matter and separation (a person against an even blue sky would be easier than someone in a green shirt against a field of grass, for example). The magic wand or magnetic lasso tools can get you started with this, but ultimately there is always some degree of more manual work required to create the best mask. For more info look into how to create masks...which will probably also lead you to several 3rd party mask-creating programs such as extensis mask pro and others. These are not necessary and can be costly, but may be of great help if you plan to do this a lot.

I order to achieve a film-like look, take a look at this site's article on converting color photos into black and white. It has techniques on how to mimic the use of contrast-enhancing color filters.

[jlsphotography]

Hi!
This is the procedure that works well for me, there are others as well, but I've found this to be quick & easy.
1) open photo in Photoshop
2) go to "layers" - click "duplicate layer" - click OK
3) go to "image" - "adjustments" - click "desaturate"
4) choose eraser tool (with opacity & flow at 100%, hard - edged brush) and simply erase through the top layer to reveal the color beneath.
5) save the file in your favorite format.

[wings4me]

Excellent tip thank you, I wonder if this will work in Gimp just as well. I will give it a try!

[The Blue Boy]

All the above is good. There is one way to use one layer however. Convert image to B&W (Using whatever method you prefer) then use the History brush over the select areas you wish to retain colour.

[Davey]

There is always the desaturate brush too but never tried this. The way I do that kind of thing to completely remvoe colour is the layer mask on b&w over original colour as mcq suggested already. I like that because it's easy to get hard/soft edges by changing brush and easy to undo since you can change between white and black and is adjustable even after a save (if in psd, or psb too I presume etc) and your edits are not dependent on history cache, plus you don't need to undo worked on bits of the image you like if you decide to go back a fair few steps to unchange an earlier adjustment. Layer masks can seem daunting but you'll get the hang of them very quickly (I did so everyone can ).

The other thing that might be worth while experimenting with which is related to this is using the colour channels tools to tweak stuff. I have done quick edits on a few this way when I wanted to selectively desaturate certain colours. eg. to leave just the reds and purples in an image you just turn the saturation sliders down in the other colours making it b&w except for the red / purple or whatever combo you want.

[dendrophile]

Guys,

I'm afraid that I am not patient enough to use the painting tools in photoshop. Anytime I get to use these tools it makes me feel like a clumsy oaf. I have tried tablets (the mouse replacement type, not chemicals!) and they certainly help. What I typically do when I want to make these "pop art" type photos is to use the colour selection tool (Select->Color Range), sometimes using just one channel as Davey describes. This way, if I have a red flower against a predominantly green foliage background, I can select the flower by just asking Photoshop to select the reddest pixels. I assume that the Color Range tool feathers the selection based on how red (or how close to the chosen color) the pixels are. Anyway, once I have a selection, I duplicate it to a new layer, and then desaturate or use channel mixer on the bottom layer to convert to grey.

Oh, I guess I should add that I often need to use the rectangle selection tool to remove obviously "wrong" parts from the selection.

Here is one example.

Hope that helps,
Graham

[Hansm]

I use the same method as jlsphotography does.
If you really want to get very nice BW conversion I can recommend Nik Silvereffex.
Very good plugin but a little pricy.
It also makes an extra mask and again you can paint or erase whatever you want.

[Fergi72]

...
If you really want to get very nice BW conversion I can recommend Nik Silvereffex.
Very good plugin but a little pricy. ...

And I can recommend SilverFast.
It's also a great scanning software (if anonymous wants to digitize his analog pictures).

The clear differentiation between colors of the original color image can get lost in an automatic conversion process, because the resultant grey shades may be adjacent. In magazines and newspapers this often results in grey images, which do not have very detailed shades. SilverFast's SC2G, Selective Color to Grey, can maintain the grey shade differentiation by controlling the conversion process. For all six colors: Red, Green, Blue, Cyan, Magenta, Yellow, the user can control into what shade of grey the color will be converted.

[Davey]

I looked up silverfast, the price Is there much you can do with it that ps wont do? I'm a fan of ps and although it's expensive (although they have great charity and edu discounts) it's very powerful and does a very very broad range of things well.

I'm not saying I doubt silverfast is powerful as I'm sure it is but it doesn't seem to have a wide range of applications and looking at its features ps can do most of those things too. Granted it isn't the best for HDR out the box but if you invested in plugins for ps you could do much more, such as proEXR which enables layers for HDR images (and other things openEXR doesn't), I reckon you could do a lot more for a lot less cost doing it that way. I'm not saying I'm right on this, more questioning is silverfast really worth it because I might be missing something but it seems a little overpriced for such a limited application (although not the worst, I think maya has got to be one of the biggest ripoffs (granted most people I know who use it have free edu license versions from college/uni if they need it)).

[Daniel Salazar]

Hi, or you could use Color Efex Pro 3.0, a plug-in developed by Nik software. You just have to select the B&W conversion and then with the selecting point choose the area you would like to keep in colour.