Are there laws of physics governing how good a small lens on a phone can ever be?

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My DSLR has massive chunky lenses but takes amazing photos, but every year camera phones get better and better with tiny lenses. Will they ever get as good as the chunky lenses or are there laws of physics (such as the amount of light that can enter a small lens) that will limit how good a camera phone can ever get?

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4 Answers

Anonymous 0 Comments

There are laws of physics governing how good a small lens on a phone can ever be. Camera phones have gotten better and better over the years because of technological advancements that have allowed for smaller and smaller lenses. However, there are limitations to how good these lenses can be. The size of the lens affects the amount of light that can enter it, and therefore affects the quality of the photo. Lenses that are too small will not be able to gather enough light to produce a high-quality photo, so camera phones will never be able to achieve the same level of quality as DSLR cameras with chunky lenses.

Anonymous 0 Comments

theres laws that amount to bigger lenses always having better image quality than a same-tech small lens.

diffraction limit and light gathering area for example

theres also ever better methods to extract images from worse data or some nonclassical imaging techniques, like fourier cameras, that could end up shrinking cameras more with usable image quality though

Anonymous 0 Comments

Camera optics researcher here. Partially it depends what you mean by “good”.

/u/bwacos and /u/Cornflakes_91 have given good answers, but there’s a little more to it than that.

A smaller lens cannot gather as much light in a given exposure time as a bigger lens, so that’s a physical limiting factor. You can increase the exposure time, but that can cause problems with motion blur. You can increase the amplification of the light signal, but that adds noise to the image.

A smaller lens also cannot gather as much *information* as a larger lens – by which I mean fine image details, like sharp edges and fine texture. The image signal is corrupted by the finite size of the lens, and the smaller the lens, the worse the corruption. This is loss of data in the image – you can never recover it. There is image processing you can do to try to simulate the lost data and make the image look better, but there’s no guarantee that it matches reality.

Having said that, phones are doing some amazing stuff and producing photos that many people consider to be high quality. However, they mostly do this using digital processing tricks to produce image characteristics that specifically appeal to humans. If you take an *objective* image quality measurement, such as how closely they reproduce a known test image, they perform really badly. And yes, they can *never* achieve what a big SLR lens can do.

For the most part, though, people don’t care. A phone shot is perfectly fine for posting to Instagram or Facebook. It would look utter crap if blown up to poster size – but nobody ever does that (besides Apple, and they select their display photos *very* carefully). If you want a good looking poster sized print, you use an SLR or medium format camera with a big lens.

Anonymous 0 Comments

Yes, it will never get as good, but phones are becoming really good because they are using advanced algorithms to enhance the result.