If all manufacturers used the same mounts for their cameras then they could share lenses and focus more on improving optics, sensor technology and accessories instead of having completely separate lines of lenses.

So, why are lens mounts different among different manifacturers, especially the smaller ones?

  • \$\begingroup\$ Recall, that even one camera maker does use the same lens mount. These things evolve and each manufacturer adds things as needed to gain an advantage. \$\endgroup\$
    – Itai
    Aug 28, 2012 at 14:16
  • \$\begingroup\$ @Itai I think that you missed a "not" in your comment: not even a camera maker..., otherwise it is a bit cryptic, or am I missing something? \$\endgroup\$
    – Francesco
    Aug 28, 2012 at 15:17
  • \$\begingroup\$ Yes, indeed. one camera maker does NOT use the same lens mount. \$\endgroup\$
    – Itai
    Aug 28, 2012 at 15:48

3 Answers 3


First of all, the idea that manufacturers have the incentive to facilitate the sharing of lenses is not exactly economically sound from the manufacturer point-of-view: they would rather hope that one is locked in a given system (obviously customers hope for the opposite).

Second, different mounts arise from history: there are various tradeoff to be made, different technical choices and the need to remain more or less backward compatible with one own lineup (so that you can mount any EF lens on an EOS camera, even if it was designed 30 years ago: at the same time note that, e.g., older Canon lenses do not work on EOS cameras because in 1987 a new, backward incompatible lens mount, was designed). I mention Canon because it's the one that I know better, but take thas as an example only.

As a final note, some manifacturer actually share lens mounts (witness M42 for example) or is it possible to use adapter rings to achieve compatibility to some degree (to mount a M42 lens on a Canon camera, for instance, maybe losing the autofocus capability).

PS: for an interesting take on the M42 mount, read this answer.

  • \$\begingroup\$ Also Olympus and Panasonic share the same mount(s). FourThirds and MicroFourThirds. \$\endgroup\$
    – rygel
    Aug 27, 2012 at 12:09
  • \$\begingroup\$ @rygel yes, I was mentioning M42 as an example but the list could be longer and would be surely apt to change in the future. \$\endgroup\$
    – Francesco
    Aug 27, 2012 at 13:43
  • 1
    \$\begingroup\$ The Four Thirds systems are maintained by a consortium of seven manufacturers of which Olympus and Panasonic are two. Other than Sigma, manufacturers that currently have proprietary lens mounts are notably absent from the consortium's roster. \$\endgroup\$
    – Blrfl
    Aug 27, 2012 at 13:58
  • \$\begingroup\$ @Blrfl interesting note, but it is also to be remembered that some of those manufacturers make up for an absolutely dominant share of the market (and of the lenses). \$\endgroup\$
    – Francesco
    Aug 27, 2012 at 14:02
  • 1
    \$\begingroup\$ @t3, sorry, but while the Nikon F mount is the same, many pre-AI lenses will not even mount on modern consumer and enthusiast DSLR bodies. I have about ten of these lenses. If you are talking about lenses under about 20 years old, sure, the Nikon mount is consistent. \$\endgroup\$ Aug 29, 2012 at 2:13

Why do camera manufacturers use different lens mounts?

If all manufacturers used the same mounts for their cameras then they could share lenses and focus more on improving optics, sensor technology and accessories instead of having completely separate lines of lenses.

(1) Because - if all manufacturers used the same mounts for their cameras then they could share lenses and focus more on improving optics, sensor technology and accessories instead of having completely separate lines of lenses :-)

That's a pretty convincing reason to differentiate from a commercial perspective :-).

(2) Also, users who decided that the new Nikon/Sony/Canon/xxx was better could but a new body of choice and take all their lenses etc with them. As body cost is small relative to lens collection cost the current loyalty factor would not apply.

(3) A camera of any brand could be used as a backup camera and share the same lenses. Again, doesn't help promote brand loyalty.

  • \$\begingroup\$ I guess manufacturers also like having full technical control over their mounts. Canon jumped from FD- to EF-mount, while Nikon and Pentax extended theirs to accommodate technological innovations. \$\endgroup\$
    – Berzemus
    Aug 27, 2012 at 13:38
  • \$\begingroup\$ @Mattdm - just delete it if it ruins the perfection of your system. I dom't know how it gets there occasionally. Brain and fingers talk to each other and are used to the real world where people actually identify themselves within the body of their work. The strain of trashing a perfectly good system apparently sometimes triggers spontaneous outbursts of signaturitis. \$\endgroup\$ Aug 27, 2012 at 13:52
  • \$\begingroup\$ @Russel: Manners. And please, do check the FAQ, the system automatically signs all your posts for you, and it handily links to your profile. Adding one of your own is redundant. \$\endgroup\$
    – jrista
    Aug 29, 2012 at 7:04
  • \$\begingroup\$ @Jrista. Yes please, that would be welcome :-). Yes, I know. As noted above. Interpreting my above comment as apparently not clear: After many decades of adding a signature in about every other forum, one occasionally slips out of hand-brain system unnoted. \$\endgroup\$ Aug 29, 2012 at 10:36

Lens/body lock-in is largely secondary, I believe. Different companies value different technologies or methods and to achieve their goals they've designed different mounts, different controls, etc.

Would you want to be saddled with the downsides of someone else's design? Companies are looking to push the design forward (in whichever way they feel is important at the time), and using another design limits what you can do.

Imagine if Ford, BMW, Honda all had to use the same transmission design - obviously it might work for Honda, but then BMW might not be able to make engines with lots of torque because the transmission is the weak link. Or maybe the length of the transmission makes it impossible for Honda to make a compact car, etc.

  • \$\begingroup\$ Actually not a great analogy, lots of Ford and BMW cars use the same transmissions. Most old photographers (shooting a long time, not old in age) have more money in lenses than in bodies. The lock-in is important, and probably of equal importance to the brand. \$\endgroup\$ Aug 29, 2012 at 2:15
  • \$\begingroup\$ If every automobile (car, truck, suv, etc) used the exact same transmission was my point - it wasn't supposed to be a perfect analogy, there is a lot of component sharing across automotive manufacturers. My point was, each company has it's own values on what makes a great camera and will have different methods of achieving this. No manufacturer wants another's values imposed on them, thus limiting what they can do - if they can help it. \$\endgroup\$
    – camflan
    Aug 29, 2012 at 2:42

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