[JJ_SO]

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JoJu,

 

I never found a failure copy of the STM, which is a godsend since it is nonadjustable and lensrentals owns exactly 10 of them.  The otus I found one failure copy of, but it had rented something like 36 weeks which is a very high amount and had probably been dropped a bunch. 

 

LensRentals has 40-50 copies of the Otus between EF/F mount.  More expensive lenses are kept in higher stock than less expensive ones because they rent more.  There is a sweet spot around $2000 though.  There's something like 700 copies of the canon and nikon 24-70s and 70-200s combined.

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So, there are correlations between rental time (=risk of damage increasing by different customers and their kind of use), design of the lens and number of samples? Of course, it's close to impossible to do this kind of mass-testing before all lenses went out for rentals because customers are waiting and the longer lensrentals keeps them waiting the more possible they try to get it elsewhere.

 

I don't want to talk this results down. But rented lenses have a harder live than the bought ones and I'm not talking about scratches. I know that lensrentals is checking each copy coming back from a customer, I don't know how far this check goes. And to be honest, I couldn't estimate it since i didn't study optics.

 

The tests are very interesting, however, I suspect in real life (customer buys one copy) results would change a bit from country to country (number of ordered copies and relevance for the manufacturer) and from dealer to dealer (repair-carousel). So, your testing tells me a lot about lensrentals' situation but I'm insecure to put this results 1:1 into my buying behavior. But the good news is: Since we talk about those issues and the "mint-conditions" the lenses arrive in, at least some manufacturers will put more care into their production.

 

What I see: At least Sigma already did and is not at the bad end of the results, given the highly competitive prices and redesigned mounts. So, for primes we customers do have real choices. If we're willing to wait  <_<