Alley in Pisa, Italy

by Lars Kotthoff

submit your photo


Hall of Fame
View past winners from this year

Please participate in Meta
and help us grow.

Take the 2-minute tour ×
Photography Stack Exchange is a question and answer site for professional, enthusiast and amateur photographers. It's 100% free, no registration required.

I have come across many reviews of lenses, in which reviewer will stress on the point that this lens has a metal mount. I am yet to buy a lens with metal mount, but what are the advantages of having a metal mount over plastic mount? Is it more durable? If so, how?

share|improve this question
    
A metal mounts advantages are any area where the following are no advantages :-) - Plastic mounts are almost invariably provided because they are low cost compared to metal ones. They allow a lower cost lens to have a far smaller percentage of the cost attributable to the mount. They are almost always less long lasting and more likely to break if dropped or knocked or just treated roughly. They tend to be lighter to much lighter. –  Russell McMahon Dec 31 '12 at 11:12
    
Plastic mounts are only used on kit/budget lenses to keep the cost right down. Metal is the norm for lens mounts, so it's not a choice that is likely to come up often! –  Matt Grum Dec 31 '12 at 11:32
    
Pentax does offer some lenses with plastic mount in kits, but metal mount when bought separately. So among second-hand offers, you might actually have a choice. –  Imre Dec 31 '12 at 15:02
add comment

1 Answer 1

up vote 17 down vote accepted

Metal mounts are generally able to withstand wear and tear better than their plastic counterpart could. This is especially so for higher end lens that are heavier because of increased amount of glass elements and/or heavier, sturdier components that are used in the construction of the lens.

For example, a Nikkor 70-200mm f/2.8 weighs around 1.4kg. If someone were to hold the camera by the body alone without any support on the lens, this could lead to potential damage in the mount area. Both the DSLR body and its lens could reach up to a substantial weight and the only part that is holding it together is the lens and camera mount. The camera mount is usually made of metal, while lens mounts are either made of metal or plastic. As the proverb goes, a chain is only as strong as its weakest link and the link in DSLR is the mount.

This is just an extreme case example. In most cases I believe (I have not yet stress tested any metal or plastic mounts), the camera maker/lens maker would have made the lens mount with sufficient strength for daily use. Reviewers mention the metal mount so that users can have peace of mind when:

  1. Heavy lenses are coupled with a metal mount instead of a plastic mount (for durability purpose).
  2. Lens that comes with metal mount (gets your money's worth).

That said, it doesn't mean plastic mounts aren't worth anything. It helps to reduce the weight of the lens to reduce the stress on the user during extended use (covering an event or during travel). It could also possibly mean reducing the cost so that prosumers can get their hand on decent lens without selling off an arm or leg without compromising too much on the quality of the glass.

Alas, this is the end of my opinion. Do correct me if I had said anything wrong. Just a hobbyist's opinion on this matter.

share|improve this answer
2  
Good answer; but the weight of the camera is really irrelevant in your example. When you are only holding the camera body, the weight of that body has no bearing on the force applied by the weight of the lens. Now, if you're holding just the lens, then the weight of the camera body would be relevant... but you shouldn't ever have a reason to do that :) –  Flimzy Jan 1 '13 at 10:43
1  
One more positive of a plastic mount over metal is that it won't rust or corrode after 20-30 years. Of course, the mount will probably have broken by then, so maybe it's not a big advantage :-) –  geerlingguy Jan 1 '13 at 15:34
    
@Flimzy Haha, but I've seen people that hold and hand over the camera by holding just the lens (with one hand). Thought it'd be good to mention. :) Thanks for clarifying my answer :) –  tctham Jan 2 '13 at 1:23
    
Clarifying edit to remove weight of the camera. –  Reid Jan 7 '13 at 16:11
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.