Tuesday, July 23, 2019

The attraction of "portrait mode".

The advent of the iPhone 7 plus and its "portrait mode" in 2016 introduced the wider general public to a new word: bokeh.

Using distance info gleaned from the phone's dual cameras, and a bit of computational wizardry, the phone would blur the background of a portrait subject.

iPhone 7 plus generated "bokeh" of Huck. Notice that in simulating the bokeh, the phone camera vanished his whiskers entirely. Subsequent software and hardware updates have improved the appearance of "fauxkeh", but you still see occasional bloopers.
This gave the photo a "pro" look for reasons that most people couldn't put their finger on, but the cause is due to the way the in-focus areas (known as depth of field or "DoF" in photography jargon) of a picture are determined.

Basically, the smaller the sensor and the smaller the aperture relative to it, the less background blur (or bokeh) you're going to get at normal portrait distances. And cell phone cameras and point&shoots have tiny sensors and relatively small apertures. Generally, the only way you'd see significant background blur in a head-and-shoulders portrait would be with a DSLR-sized sensor, so those sorts of photos got subliminally tagged as "taken with an expensive-ish camera by someone who at least considers photography a bit of a hobby."

Huck shot with a Fujifilm X-E1, which has an APS-C sized sensor, like you'd find in a DSLR, using a Zeiss Touit 32mm f/1.8 lens shot wide open.
With the sensors found in P&S cameras and cell phones, background blur usually only shows up significantly in extreme closeups (or "macro mode", the little green flower button you want to push for taking pictures of bitty things up close.)

If you've seen older manual focus camera lenses, that is, by the way, what that hockey rink's worth of painted lines are for. On some lenses, Nikon even color-coded them to make reading them easier. If you look at the zoom lens below, you'll notice the aperture numbers are color-coded. If you set the aperture and then focus the lens on an object, the two colored lines will point to the nearest and farthest in-focus distances on the lens's distance scale.