So… How do photographers…?

Kerry asked me today: “how do photographers do that thing where they make a picture black and white except for one thing, like a rose or a red balloon?” To which I replied “magic.” Which is, of course, the official party line.

Then she said “Yeah. I know. Never reveal your tricks. But srsly, how do they do it?” I thought about it for a full eight seconds before I said “Photoshop. Or Lightroom. You could probably do it in Lightroom.” Then I showed her. For the curious, here’s how you do it. I started with this photo from Tucson.

I’m going to grey everything except for the butterfly. I’m going to do it twice: once in Lightroom 3 and once in Photoshop CS5. In both cases, I started with a CR2 that I had previously cropped and color corrected using Lighroom (which has all the same tools as the Adobe Raw Converter that comes with Photoshop).

In Lightroom, you use the adjustment brush. You set the “effect” to “color” and set the “saturation” to “-100.” Then you paint the whole photo except for the part you want to be in color. You’ll have to zoom in and do some fine tuning, but the adjustment brush has an “erase” mode that will put the color back in (took me a minute to figure out that bit). That’s about it. Like everything in Lightroom, pretty simple with pretty good results. Here’s what you end up with.

Pretty good, but we can do better. Let’s load up Photoshop.

Start by making a selection. It won’t be perfect, but doesn’t need to be at this point. I used the magnetic lasso, but you could just as easily use the regular lasso or the pen tool. Select the butterfly. Next, click the “edit in quick mask mode” button at the bottom of the toolbar. This works just like a layer mask, except that instead of hiding part of the layer, you’re selecting it. You use the brush tool in black and white to edit the mask. By default, the mask appears red. For this particular project, I turned mine blue by double-clicking on the quick mask mode button because red didn’t contrast well enough with the orange butterfly. So this is what a quick mask looks like:

That’s what mine looked like when I was about half-done with it. So, make sure everything you want to be greyscale is covered with blue (or whatever color your quickmask is) and whatever you want to be in color is not. Using the brush tool (b) with black selected paints the mask, and using it with white unpaints it (hit x to switch between black and white when you have one as the background as one as the foreground). I could have that backwards. I can never remember.

Once you have your mask just the way you want it, click the quick mask button again. That will take away your mask and replace it with a selection. This next step is vital. Go to the “select” menu and click the “inverse” option. This will select the part of the image that you had masked, as opposed to the part that was unmasked.

So now you’ve got a selection of all the stuff you want to have no color. Now, go to image>adjustments>black & white. This will bring up the “black & white” dialog. If you know what you’re doing, click “auto.” Then make adjustments until you’ve got what you want. If you don’t know what you’re doing, click “auto,” then play with the sliders until you figure out what’s going on. Make sure you’ve got the “preview” box checked or you won’t see what you’re doing. Make everything as light or dark as you want it. When you’re done, click “okay.” Done. You should have something like this:

I just took the auto black and white settings (not to be confused with the default settings, which are what show up in the dialog before you hit the “auto” button) and didn’t change anything. I think this turned out a lot better than the Lightroom method, and it was easier (if more tedious) to make a perfect selection.

So, that’s how photographers do that. But remember: if anybody asks, the answer is “magic.”