Can a lens get worn out?

gjl711 wrote in post #16629220
Is it really profit? I think that it's more mass affordability with a little profit tossed in. The less expensive you can make a lens, the more people can afford to get it. But less expensive also means poorer workmanship. It's hard to do both high quality workmanship and low cost at the same time.

I would have to disagree. Manufacturing these days is far more precise than it was even 10 years back and the new lenses coming out proves it. You can have cheaper and better, especially if a process becomes more automated and faster/cheaper to produce.

As for profit, take a look at sigma. they have been able to produce at least one lens of late that easily rivals, if not beats the Canon version that costs 50% more. (with more on the way that hopefully also equal the great results)

mikeinctown wrote in post #16630595
I would have to disagree. Manufacturing these days is far more precise than it was even 10 years back and the new lenses coming out proves it. You can have cheaper and better, especially if a process becomes more automated and faster/cheaper to produce.

As for profit, take a look at sigma. they have been able to produce at least one lens of late that easily rivals, if not beats the Canon version that costs 50% more. (with more on the way that hopefully also equal the great results)

While this may be true, "more precise" does not necessarily equal good build, or good raw materials. A lens can be engineered to great, tight tolerances and have shoddy parts to build it, like plastic gears etc.

KirkS518 wrote in post #16629500
True for both.

But what is a lens? A bunch of glass, plastic, a circuit board, and some wires held together with screws and precision fitment.

The glass won't wear out with normal care.
The plastic won't just crumble (at least not in our lifetime)
A circuit board usually lasts decades+, as well as the capacitors and other components
The wires may wear by developing weak points with heavy usage (compressing, twisting, etc. when focusing/zooming, etc.)
Screws may come loose, but that's what locktite is for
Fitment is fitment

I think the biggest weak points in today's modern lenses are things like the Teflon (?) rollers, guides, etc., and those incredibly delicate ribbon cables.

I am afraid I have to differ...

The glass won't wear probably but coatings will and change properties through time.
Plastic can get brittle over time - even the best - especially when regularly exposed to UV in strong sunlight.
Circuit boards may last a lifetime but the components don't. Capacitors have a limited life span, especially when at strongly varying temperatures. Tolerances/values change with aging, affecting the accuracy of measurements.
Yes - the flat cable controlling the aperture mechanism on my 24-105L wore out after 3 years daily use. Insulation of cables becomes brittle through time.
Lens fittings may wear when you change your lens on the body regularly.

Depends on how often and under what conditions you use a lens, but IMHO modern lenses (even L type Canon) will wear out after 5 to 10 years.
I had to replace a 24-105L after 4 years (aperture ribbon cable worn out) and have problems with the tightening ring on the 100-400L after 3 years.

So you guys are saying that photographic lenses are no longer considered durable goods, and should now be thought of as disposable, with a life span of up to 10 years for the top end lenses (L's)??

It just so happens I have a proper disposal site for all your 5-10 year old lenses. Send them all to me, and I'll be sure they are disposed of properly!

Thanks for the replies everyone. Very interesting debate on the durability of commercially available lenses. John_T ... I think Jacobs has closed down? Which is a shame as I live close enough to there to be able to take the lens in for a once over.

I think my main point has been answered ... This bit of kit is getting past it's best. May look at calibration, but, to be honest, this looks to me like a shopping opportunity ... And time for a fresh start. Thanks again all.

Hmm, I don't know about Jacobs, but they are still listed by Canon. You could check other options here: http://www.canon.co.uk …rvices_locator/​index.aspx

...but as you say, it may be a sign from the Gods of Imaging that it's time for a new window into the Universe. Check out the EF 24-105L, a worthy replacement.