Early 35mm film cameras, esp. movie ones, used lens turrets, ie. a ring with 3 or more pre-mounted lenses that you would rotate to switch between lenses. I'm talking about this:

lens turret

I do wonder - why not use the same mechanism for 3-4 lenses on a smartphone, with the existing phone lens size, of course? This way you lower the cost of having 3 or 4 sensors, instead of installing only one, and you're always using the best (largest) sensor - unlike now, when usually the wide (ca. 26mm FF equiv. ) sensor is the biggest (close to 1" these days for flagship phones).

Reliability can't be an issue, since the manufacturers were bold enough to try pop-up mechanized cameras, so surely they COULD try this, at least one of them.

Complexity can't be that much of an obstacle either, since hinge mechanisms with foldable have been introduced and refined at great expense on R&D. And they made it work. Surely they can figure out the turret rotation.

Yet none did so far. And the advantages and cost reduction will only increase as we move to greater sensor- and lens sizes, so can anyone with the technical or industry knowledge let me know if it's somewhat likely down the line (like a decade from now)?


3 Answers 3


A few points why not:

  • having such device involve sealing rotating part of phone which is not very easy and manufacturers try to minimize such details
  • to make smooth rotation manufacturers need to add bearings (very small one) and this is another challenge because they need to be lubricated occasionally. And even be small they use some space in the phone.
  • for such rotating device you need to make stable construction (to keep lens always to be parallel to the sensor). And such stabilization can "eat" a lot of space which is short in the phones.
  • in phones AFAIK telephoto lens are created as periscope so to put such lens in such device make it bigger and more complex.
  • and last but not least - psychology. End users do not know how to deal with such device and want only to click on the screen and do not rotate phone and turn some rings. At the end cameras as above are managed by professionals who know how to deal with such devices.
  • \$\begingroup\$ you make good points, but for the final point I have a very simple solution... motor. Of course, this does add to the space constraint, so it has its pros and cons \$\endgroup\$
    – Topcode
    Commented Oct 30, 2023 at 2:51
  • \$\begingroup\$ @Topcode, every moving part in phone will decrease reliability of the device. Think about the fact how many motorized parts you have in contemporary phone. Plus space.... \$\endgroup\$ Commented Oct 30, 2023 at 6:01

To add to the excellent reasons already stated: modern phone cameras are a very long way from your simple "open shutter, read one frame from sensor, write data from that one frame to a JPEG file" that you may think of from simpler systems. As soon as you open the camera app, modern phones are simultaneously and continuously processing data from all the lenses in order to do the clever computational photography tricks that they do - scene identification, object identification, depth mapping, etc. Your proposed scheme would remove a lot of that power as it would be possible to obtain information from only one lens at a time.


Users don't want this. Users want simplicity.

Manufacturers don't want this. Manufacturers don't want complex mechanisms, they want electronic/software solutions where possible.

You are thinking like an engineer rather than a business analyst or end-user.

  • 4
    \$\begingroup\$ more specifically, steampunk-era engineer! ;-) \$\endgroup\$
    – szulat
    Commented Oct 29, 2023 at 1:44

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