In article , David Dyer-Bennet
wrote:

four lenses is nothing.

lensrentals has *hundreds* of sigma lenses. dozens *each* of nearly
every model sigma lens made.

well they used to, until they found out that sigma lenses had horrific
failure rates, as high as 90% (really). many of them failed out of the
box, before they were even rented to anyone. worse, sigma gave the a
runaround to get them fixed, blaming lensrentals for breaking them.
there was a lengthy blog on their website about it.

Yeah, but those claims of hugely high failure rates ring false -- and
four lenses is getting to the point where "90% failure" should probably
show up.

if you bought four of the same lens it probably will show up.

on the other hand, if you bought four different lenses with different
failure rates (only 1 had a 90% failure rate) then you might not.

more likely, people didn't test the lenses the bought since they don't
realize they need to or they just don't care, or the failure has not
yet occurred, such as a motor failure.

lensrentals *has* to test the lenses, because shipping defective lenses
to customers is not a good business model. they also want to know if a
renter damaged it.

I strongly suspect people who rent lenses are much harder on them than I
am on lenses I'm using.

maybe so (remember, damage isn't covered so most people will be
careful), but what is significant is that many of the problems were
with lenses that were new out of the box and never rented to anyone.
sigma blamed lensrentals for damaging them, more of the usual bull****.
opening a box is not 'user damage.'