[Mankaninen]

While f/64 sounds like a small aperture, it can be worth remembering that it was on large format cameras. A small sensor like on iPhone 6 is wide open corresponding to depth matching f/113! (iPhone6 is f/2.2, crop is 7.21, 8"x10" camera is crop 0.14. 7.21/0.14*2.2 = f/113)

[klodolph]

Worth noting that angular resolution and DOF/defocus is related to absolute aperture size, not f-number, so you can also just plug in the values for "f" to compare.

The iPhone 6 has f=4.15mm, a lens with similar FOV on an 8x10 has f=200mm.

200mm / 64 = 3.1mm -> the size of an f/64 aperture on a 200mm lens.

4.15mm / 2.2 = 1.9mm -> the size of on f/2.2 aperture on the iPhone 6.

Although the 8x10 will often have less defocus due to movements (photographer control of focal plane).

[m463]

It still give me the mental image of a good lens with a meticulously crafted iris that can close way way down.