Limit to how many shots from a lense?

[Wobble]

Im new to SLR so bear with me if this is a stupid question..

ive been looking at the classifieds here a bit at lenses.. and I notice how many ads feature the number of actuations or shots that it has "been through"

from what I get from this is that.. a lense.. can only take so many pics before it.. sort of "wears out"...

is that true?

[imanooblar]

i believe the number of actuations (shots taken) is referring to the actually slr camera body itself, specifically the shutter. you should be able to take as many picture off a certain lens as you want, but the camera shutter is limited to a certain number, ie. the Canon Xti is rated at 35,000 actuations. I don't know if that number is correct, but that is what i just found in google. hope that helps.

David

[Wobble]

and what happens when that number is reached? or.. whatever number that gets it to where its worn out? do you send it off to get rebuilt? have to buy a new body?

ive had my rebel XT for a week and ive already taken 1091 pics..

[Master Mason]

The rated number is MTF Mean time to Failure.

Which means the tests some number of cameras, and averaged out where the shutters failed. In the 1 series, they are rated in the 100K range, I acutally don't think that canon posts figures for the rebel series.

You could go many more than the rating, or less.

[Tee Why]

The shutter/mirror might break, requiring a replacement shutter blades or a mirror.
I think XT/XTi's are geared to survive 50,000 actuations.

[Wobble]

well crap.. no more blasting away I guess..

[dgcorner]

The shutter is like life -- you don't know when you are going to croak :-) So enjoy your camera for tomorrow may never come.

[ramblingman]

I've read that my D20 is around 100k.

[WMS]

Actually there might be something to the question as it related to lenses. Every time the shutter is clicked it is reasonable to believe that the lens stops down, unless all photos are taken wide open, then there is the zoom actions as well as the focusing actions. All of this mechanical movement in a semi sealed system with minimal lubrication would theoretically cause some wear.

Of course most of the mechanical components of a lens are relatively slow moving, compared to the shutter and mirror in a SLR.

WMS

[ed rader]

Im new to SLR so bear with me if this is a stupid question..

ive been looking at the classifieds here a bit at lenses.. and I notice how many ads feature the number of actuations or shots that it has "been through"

from what I get from this is that.. a lense.. can only take so many pics before it.. sort of "wears out"...

is that true?

i got about 50 shots from my first L lens (70-200L f4) before the AF croaked.

ed rader

[SaSi]

It is obvious that the lenses wear out because of use. Normal use of a lens doesn't really stretch it out very much mechanically. It's more like using a lens for 10 years will inevitably expose it to accidents, incidental abuse and other mishaps that will cause dents inside and outside. These will eventually cause the lens to fail.

It's also possible for a lens to fail without any external abuse. Mount a lens on a camera and put the combo on a table and start shooting tethered from the PC at 1 shot every 3 sec for a few months. Without toutching the lens and the camera, inevitably the whole thing will fail eventually. Most likely the camera will fail first and it might take several body replacements before the lens fails - if it fails.

But even the camera body will likely start showing symptoms of ageing before it fails. The shutter might start squeaking first (signaling lack of lubrication) that can be temporarily fixed with a refit. But the blades of the shutter get subjected to a lot of friction between them as well as rapid movement. The shutter actuator level also gets subjected to rapid movement and friction. Something in this whole system will eventually fail, no matter how frequently or carefully everything is serviced.

As you see, I need to focus on issues with the camera body, because this is where the failure is most likely to happen first.

The lens apperture blades also get punished everytime a shot is made. Stopped down shooting with an 8-10 fps camera in burst mode is also more demanding on the lenses, so a lens used by a sports photographer is more likely to have more punishment internaly.

But somehow, I imagine that the apperture blades are not the first thing to go in a lens. I think that the focus mechanism is punished more. Framing and attempting shots happens more frequently than actually shooting and the AF motors must get punished much more.

The zoom mechanism is pretty simple - just a set of geared rings that have permanent lubrication on them. Unless the lens gets exposed to extended and extreme sunlight - heat, the lubrication typically ensures trouble free operation.

Honestly, I find it much more likely for a lens to be dropped and broken than fail due to overuse or old age. The camera body will eventually break, but so far, I have read and heard of several different failures in camera bodies but no failed shutter yet.

[Jon, The Elder]

Odds are higher that you will die before the lens does.

[PetKal]

There are several issues with lens life expectancy.
EMD can obviously go at any time....that's equivalent to the number of camera actuations.

A more insidiuous failure mode is related to the AF drive.
Servo AF mode is probably the most onerous way to use a lens.
As an example, I'd never buy a 200 f/1.8 which has been used extensively by a court sports photographer. Also, a used 400 f/5.6 from a BIF shooter.;)

[Miyagi-san]

If you are anything like me, you will sell your gear here on POTN well before it dies of old age. I really need to break that habit!