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The craziness in the iPhone design isn't exactly the number of elements, but their weird aspherical shapes. The traditional approaches for designing optics are
by gmueckl 5y ago
The craziness in the iPhone design isn't exactly the number of elements, but their weird aspherical shapes. The traditional approaches for designing optics are have been developed for spherical lenses because they are much simpler to describe mathematically. Even then, optimizing them requires a lot of numerical computation. At first glance, optimizing these wavy, complex lens shapes seems to require much more involved methods.
- prvc 5y agoIf only the designers at Apple had access to devices that could perform numerical computations...
- gmueckl 5y agoYou first have to know what to compute before you can compute it. A computer won't tell you that.
- fsh 5y agoI don't think the computational complexity has been a significant problem for at least half a century. Aspheric lenses are described by simple polynomials and ray tracing is just elementary geometry. You only need to analyze a hand full of rays to get the relevant parameters of an imaging system. Probably a few thousand floating point operations in total. The problem is that it is extremely difficult to manufacture surfaces with optical quality that are not spherical. Even today, aspheres tend to be more expensive than spherical lenses and have significantly worse surface quality. This is the price you have to pay if the objective has to fit inside a phone.