focus

I recently rented a Nikon 105mm VR Macro lens for a weekend, and wanted to experiment with different types of macro photography.

One of the things I was most interested in was focus stacking. See, there's a problem with macro photography in that you're dealing with a depth of field measured in millimeters when reproducing images at a 1:1 ratio, even stopped down to f/8 or f/11. And, wanting to avoid diffraction at higher apertures, there's no way to take a straight-out-of-camera picture of a 3D object that's sharp from front to back.

(There's also a video version of this post, embedded below)

The original Raspberry Pi Camera model v1.3 came from the factory set to ∞ (infinity) focus, so when you used it out of the box for something like a landscape timelapse rig, or for security or monitoring purposes (where the Pi is at least 5 meters away from the subjects it's recording), everything would look crisp and sharp.

For many fixed-focus cameras and lower-end camera sensors, it makes sense to set them to infinity focus; closer objects are still recognizable, but slightly blurry. Most of these cameras don't need to focus on a person a meter away for a portrait, and they're also rarely used for FaceTime-like video chat.