Zoom factor / camera lens choice widget

[nekohayo]

This is something I've been hesitating to ask as a feature suggestion, but I think it may have a real impact on image quality, so here's the suggestion: could the app have a zoom lens switch control widget (a bit like the flashlight toggle button) to pick which camera lens to use?

Many (most? all?) smartphones in recent years have multiple lenses, at least one for wide-angle shots and one for portrait/telephoto shots. Unlike digital zoom, this yields non-crappy magnification results.

The idea here is that when possible (ex: when scanning small receipts, in bright natural light, from a certain distance), I think the user would get better quality results from using the telephoto lens (ex: 2.00x zoom on my smartphone) because you would get no lens distorsion, so the software would not have to warp things around so much, which I would presume would yield better (and sharper) quality results.

No continuous zoom slider (as it would give you a middle-ground made of digital zoom, which would be crappy), and of course if the device only has one camera lens then hide the control widget entirely.

[pynicolas]

Thanks for sharing this idea!

Using a telephoto lens could indeed lead to different results:

• distortion: certainly. Theoretically, distortion could be compensated by the app, but that would need work and is not trivial.
• sharpness: that's a complex topic. When scanning a document, we typically want all parts of the document to be sharp. Depth of field depends on many parameters. A telephoto lens has a longer focal length than a wide angle one, so that would lead to a shallower depth of field. However, distance to subject would be higher, so that would lead to the opposite effect. Other parameters also have an impact (aperture, sensor size) and they depend on hardware.