Macro and Depth-of-Field

Before I started shooting macro, I was generally on a quest for shallower depth-of-field. Deep depth-of-field was easy because of my APS-C cameras naturally produced it. It was more challenging to get super-creamy bokeh, especially with zoom lenses. But the Sigma 18-35mm solved that problem, and then the 50-100mm extended it into portrait and short-telephoto range.

 

Shooting macro, I now have the opposite problem. I can't get enough depth-of-field. You stick a lens right up in the grill of something, and your depth-of-field is reduced to a couple of millimeters, tops. Handholding your camera, your heartbeat is literally enough to move the focus off where you want it. And so you have to change your shooting technique.

 

For regular photography, your typical order of operations is: 1) Compose the shot; 2) Hold as still as possible; 3) Focus the camera; and 4) Release the shutter. The issue with this process for macro is that you can't hold the camera still enough to get the shot. Every tiny little involuntary movement your body is doing moves the camera, taking your tiny sliver of focus off your target.

 

With handheld macro, you have to accept that situation and try to create and capture the moment when the focus is on-target. That process looks more like this: 1) Compose the shot; 2) Focus the camera; 3) Rock back and forth ever so slightly to move the focus point along your subject; 4) Time your shutter release to the moment when the focus is where you want it. It's like sports or wildlife photography in that you're waiting for the perfect moment, but the moment is defined by where the focus is located. Your success rate on this is a lot lower than what you might be used to with regular photography, but that's the only way to do it without breaking out the tripod.

An important thing I learned from macro photographer Mike Moat's site: Don't be afraid of aggressively stopping down your lens! For most of my photography life, I've diligently avoided going smaller than f/16 because my early experiments made very wary of diffraction. But I learned from Moats that macro lenses are generally more capable of maintaining sharpness at small apertures, and modern sharpening tools will take care of the rest. For example, the photo below was shot handheld at f/32. It's not what I'd call "tack-sharp" because I shot it handheld, but it does have reasonable depth-of-field for the subject. If I'd shot it using a tripod, it would be very sharp indeed, but I kind of like a little bit of softness for flowers.

The next step for me will be focus stacking. I haven't been in a hurry because I like to get a decent handle on something before incrementally adding more complications. So I've been trying to sort out my macro camera technique and how to get the most out of my gear before I start messing with post-processing techniques. But I'm starting to feel the need to explore it, so focus stacking is coming to my workflow sooner rather than later.