Weekly poll: which is the best focal length for telephoto cameras?

We never thought we’d see it on a phone that doesn’t have camera bolted to it (a la Galaxy Camera). And there’s a good reason - 5x optical zoom on a phone took impressive feats of engineering – to underline how difficult it was, we’d like to point out that no company has done it twice.

Huawei got there first with the P30 Pro, which was released in March. Then Oppo joined with the Reno 10x zoom in June. And that’s it. No other smartphone maker has a phone 5x optical zoom.

However, neither Huawei nor Oppo followed up with new models. The Mate 30 Pro dropped back to 3x. The several Renos we’ve had since June also reverted to the standard telephoto lens – the kind that uses regular optics instead of a periscope contraption with a 90° bend.

Difficulty is only part of the equation – the other part is practicality. 5x zoom is too much for some, they find that 2x or 3x is the sweet spot. Thanks to “hybrid zoom”, you can make a 2x camera go to 5x. But there’s no way to make a 5x camera go to 2x.

We should note that “hybrid zoom” features are based on super resolution algorithms that perform better than classic digital image upscaling. Obviously, the results aren’t as good as purely optical zoom, but in practice many find them good enough.

Anyway, it’s important to remember that unlike the Galaxy Camera mentioned above, the current zoom cameras used fixed optics – they can’t smoothly zoom from 1x to 5x. That means you’re stuck at their designed focal length and everything else uses some form of digital zoom.

That’s why 5x telephoto cameras are not always practical – in many scenes it proves to be too much magnification and then you’re left with hybrid zoom.

Given the current trend, we don’t doubt that we’ll see phones with two tele cameras. Maybe in 2020, maybe in 2021, but someone will make a phone with a 2x tele and 5x periscope camera.

Until then, which focal length do you find more versatile? Which zoom ratio do you use more often?

Note that a simple “2x” is vague, but smartphone cameras use roughly the same focal lengths so a 2x cam from one maker is pretty comparable to a 2x cam from another maker - normally about 52mm focal length.