Sure. But that's frankly overcomplicating things. The people considering the iPhone 7 [Plus] as their camera don't need a detailed discussion of the factors that affect depth of field. Hell, Apple was calling this Bokeh. What the typical consumer needs to understand is that a large aperture on their phone won't make it take pictures that look like a DSLR.
> It doesn't look like the iPhone 7+ will really do this either, but employ some software tricks and perhaps a rough depth map to do slightly better than a simple filter would. The examples seen so far were hardly compelling.
Yeah, I don't have high hopes for this either.
> Fwiw, depth of blur for portraiture and sports photography are usually achieved through different mechanisms anyway, on being focal plane location and the other (mostly) motion relative to that plane
I'm not sure what mean here. I'm not aware of anyone doing lots of portraiture that involves any motion at all. And sports photography is typically shot with a fast enough shutter to largely freeze any action. The obliterated backgrounds in portraiture and sports photography is mostly achieved by using long lenses wide open.
> The "portrait" look that most people actual want is achieved through foreshortening as well as blur, and you aren't going to achieve that with the (typically quite wide) optics on a smart phone. Even the 7+ "tele" is actually a normal, it seems.
I agree, though I think more people are conscious of the blur than the perspective difference.
Wrt sports photography, sure you shoot long and open like portraiture, but for sports you are trying to freeze motion. You usually do this by getting a fast enough exposure and also tracking the subject. As a result in many/most situations the background is moving faster relative to the subject than the subjects motions are (in this frame of reference). Hence blurring, even if the optics alone wouldn't give you much...
My point was that you can't really talk about bokeh without considering subject distance relative to effective length. That shouldn't be controversial. You're right that background blur and DOF but even that is an oversimplification (circle of confusion comes in here, "sensor size" is a proxy for this but flawed). This wasn't intended to be misleading, just pointing out that the conversation was too superficial.
It's true (and I didn't deny it) that a phone sensor won't do this for typical portraiture.
It doesn't look like the iPhone 7+ will really do this either, but employ some software tricks and perhaps a rough depth map to do slightly better than a simple filter would. The examples seen so far were hardly compelling.
Fwiw, depth of blur for portraiture and sports photography are usually achieved through different mechanisms anyway, on being focal plane location and the other (mostly) motion relative to that plane.
The "portrait" look that most people actual want is achieved through foreshortening as well as blur, and you aren't going to achieve that with the (typically quite wide) optics on a smart phone. Even the 7+ "tele" is actually a normal, it seems.