I do a lot of professional portraits for, well, professionals. Attorneys, financial advisors, authors and many others need well done photos of themselves to better market their services. My standard rig for this kind of assignment involves a fair bit of equipment – a muslin backdrop with stands, a couple of Alien Bee monolights with stands, umbrellas, and softboxes, plus cameras, lenses, and my trusty MacBook Pro which I use so the subject can immediately proof the images as we shoot. Sometimes I get lucky and can set up in an empty office or conference room, but more often than not, I have to squeeze into a very tight space.
Such was the case the other day when I shot portraits for a local family law attorney. The biggest problem with tight quarters is that it changes my preferred geometry of shooting. Whenever possible, I like to put a certain amount of distance between the subject and the backdrop. This accomplishes a couple of things: it lets the backdrop go mostly out of focus so it is less distracting, and it also lets the backdrop go darker, which is (usually) the desired effect. But in a tight space, the subject is only a few feet in front of the backdrop so that even at a wide aperture, the backdrop will be too much in focus. And setting the lights to give good illumination for the subject means too much illumination for the backdrop.
So what to do? How about increasing the distance between subject and backdrop after the fact? It sounds too good to be true, but this is essentially what I do when I digitally post-process portraits shot in tight spaces. The “before” and “after” attorney portraits above are a good example. The image on the left is the original photo with no adjustments or retouching. The image on the right is the retouched version. How did I get from one to the other?
The key to this kind of retouching is to get a good mask/selection of the subject. Once I have that, I can selectively darken and blur the backdrop, giving the illusion of depth. To mask out the subject, I usually start with the Magnetic Lasso tool in Photoshop. This can be a frustrating tool to use, especially when there is little contrast between subject and backdrop. One trick is to temporarily ramp up the overall image contrast to absurd levels with an adjustment layer just so the Magnetic Lasso tool works better. Once you have the selection, you can delete the adjustment layer. Another approach is to start with a fairly gross level selection, then refine the selection using finer and finer settings for the Magnetic Lasso tool.
Once you have the selection, you need to make some adjustments to it so the blurring and darkening we’ll apply look natural. This essentially involves expanding the selection so its boundaries are just outside the edges of the subject, then applying a large feather to the selection. Once this is done, a Curves adjustment layer, and a quick Gaussian Blur will yield the desired results. Often, this technique works so well that the end result looks almost three dimensional.