The image pipeline in the iPhone gets more and more advanced with every IOS release. The state of the art for computational photography is pretty amazing.
(unless you shoot in raw, and I haven't read enough yet to know what processing, if any, Apple does to ProRes/RAW photos).
Call it "tricks" if you want. I call it using technology to give the non-professional camera user the best photo possible at the time. If that bothers you, pull out the DSLR, shoot in RAW, and spend time afterwards in Photoshop/Lightroom.
edit this is also why apps like Halide (or ProCamera or Filmic Pro) exist... if you want to control more of the options instead of letting Apple choose, the capability is out there. Most users probably don't care. They just want a good photo of their kids to post on Instagram.
By the same token, I wouldn't call Google docs as 'state of the art' since its duplicating existing desktop software, but in a browser (not to minimize their effort, I'm sure its hard).
Full frame sensors have thin depth of field. Small sensors like an iPhone don't have that, so they fake it with portrait mode.
But when you do macro photography, having thin DoF becomes a drawback, so with big DSLRs you have to do focus stacking (which is unnecessary on an iphone).
...when they have a large aperture. Stoping down the lens will widen the DoF on that full frame sensor
>so with big DSLRs you have to do focus stacking
you don't have to. only if that is the style you are wanting to achieve. you can also stop down the aperture. it's not as obvious as non-macro, but still something doable.
This is why focus stacking exists for macro on DSLRs, as when using a true macro 100mm lens you basically have only a thin sliver of usable DOF at reasonable apertures.
https://www.photopills.com/calculators/dof
(That site has different camera selections purely because the circle of confusion differs based upon the sensor size / resolution, so it's the relative values that you should pay attention to)
Take a gander at the DoF variations for a 4mm versus a 35mm FL system.
This is the reason why iPhones have to implement fake bokeh -- because the depth of field on tiny cameras is so much larger, even with a wide open aperture. But the inverse is that where you want a wide depth of field it is a feature of the size. It's also why people seem to be much more successful taking photos on smartphones, because the focus is much more forgiving.
A wide DoF is a function of those physics.
