Fashion trends affect every sphere of our lives and our work is certainly no exception. There's a look in product photography that I'm seeing everywhere these days: hard light against white backgrounds. This particular treatment makes for very crisp, sunny "middle of the afternoon" images with a lot of pop.
But usually while the shadows and edges are very defined, the products retain a softness and roundness in terms of texture that's associated with softer lighting. So how does this work? Well, we can go crazy with light positioning, trying to get that perfect ratio...or we can start thinking in layers. The trick is stacking.
Basically, we use two lights: one for softness and one for shadows. But we don't use them together. Instead we shoot two images—one for each light—that we'll then combine in Photoshop or any other image editor that supports layers and masks. The advantage of this method is the amount of control we gain over which area gets a hard or soft treatment. It's then completely up to us to decide what works best. Let's do a quick case study—faults and all.
For image #1 I've positioned a Deep Octa directly overhead, fairly close to the objects (about two feet). The results are what you'd expect: soft; flat even. If I'm going for this kind of final look, I'll usually just play with the edges of the softbox by simply rotating it forwards or backwards, giving more light to either the front or back of the subject; this is a quick and easy way to create dimension. In this case however, because I'm shooting for stacking, I'm leaving it as even as possible. This is my base image.
For image #2 I'm using a 30º grid on an Elinchrom BXRi strobe, slightly behind and above the subject, camera right. The grid is focusing the beam and I've aimed the strobe directly towards the products. This is the afternoon sun, the "shadow and depth" image.
Both versions are processed for basic exposure, contrast etc in Lightroom. Once that's done I select them, right-click and choose Edit as Layers in Adobe Photoshop CC. This will open Photoshop and create a single PSD or TIFF file containing both images already stacked as layers.
From here it's all rather straightforward: I make sure the"base" image is on top and add a layer mask (Layers>Layer Mask>Reveal All). I select this new mask layer, choose a black paintbrush and start painting in the areas where I want the "shadow" image to appear. There's no recipe for this—it all depends on the image itself and the effect we're looking for. But I usually turn the base layer on and off throughout the process, to visualize what I've added or removed. With a mask we can simply switch to a white paintbrush to go over potential mistakes—it's all non-destructive. Once we're done, all we need to do is hit Save: this new image is added next to the originals in Lightroom where we can add further adjustments if we need to. Eventually, this is what you get:
A few more examples using the exact same technique (final image first; click for stacked versions)::
These are all quick and dirty examples just to give a rough idea.
If at all possible I always prefer getting everything done in one take; but sometimes the laws of physics get in the way. Stacking is a method that can prove useful for all kinds of settings: focus, exposure—anything reality can't manage in a single take. Just like bracketing. I personally never use this outside of commercial work but it's a useful concept to grasp.
Now, if I could just find that Remove All Dust, Fingerprints, Smudges And Scratches button....