Pentax smc DA* 50-135mm SDM Issue

DAVID MANZE wrote:

KentG wrote:

Its things like this that made me glad I bought a Sigma 50-150/2.8 instead.

Kent Gittings

I must say I don;t understand your almost gloating admission you are deliberately rejecting some of Pentax's optically best glass based on 3rd hand reports.?

I have used multiple SDM lens constantly since 2008 , My failure rate is in line with what I'd expect form any similar technology lens from any other manufacturer (1 failure)

which gives a MTBF of 20 Years .

Yes USM/SDM/HSM/SWM will fail more often than screw drive but the silent drive, higher torque more than make up for the shorter life cycle.

Pentax's biggest issue with SDM was managing peoples expectations rather than any inherent failure in design, anecdotal evidence points to about a 4-8% higher failure rate fro the 16-50/50-135 in their early releases again pretty much in line with new technology releases.

Failure rates now seem to be in line with every other OEM .

Other forum member have had significantly worse experience than me and some significantly better, That is life , I wouldn't base my purchasing decisions based on either rather as I did research the technology and understand the real risks.

You get the same reports from dissatisfied users for any brand you just need to look

Her you go for Sigma

"I had a Sigma EX 70-200 f2.8 hsm II that had the AF motor repaired 3 times so I sold it before it was out of warranty and bought a Tamron instead."

(Google Sigma fail  this one is over at the other forum)

If you took heed of all of them you'd never buy a lens again

Lens Rentals is one of the best places to assess real reliability of lens (notice I said lens not brands)

Dave's clichés