06-25-2014, 07:31 AM
Quote:This applies more to young mirrorless players than DSLR users. Canon and Nikon have... decades of experience building AF and IS lenses and have tight tolerances - according to roger @ LR only 2-3% of lenses from each of them are sent back as duds.
As far as copy-to-copy variance when out of spec lenses are removed, canon varies ~7% and sigma varies over twice as much at ~13%. They absolutely are not beating canikon at tolerance levels, and Zeiss is even better than those two.
Maybe it applies more to mirrorless I cannot say, what I can say however it "definitely" applies to DSLR users with regard to Pentax, Sigma, Tamron and some others. From Canon and Nikon I cannot say. My personal experiences from Sigma, Pentax and Tamron are poor,these are in the Pentax mount.
Below par modern lenses purchased:
Sigma EX 10-20mm 4/5.6 decentered returned repaired, a decent copy.10 week wait.
Sigma 50-150mm EX II F2.8, badly decentered, shop exchanged for a good copy
Sigma 18-50mm EX F2.8 badly decentered sold on at a loss.general disgust.
Sigma 50-500mm EX F4/6.3 bought S/H decentered at 50mm , living with it as I use the longer end.
Tamron 17-50mm decentered returned repaired, a good copy. 11 week wait
Pentax, DA 21mm F3.2 Limited, decentered, returned was sent another good copy.
Pentax DA* 16-50mm decentered returned for a refund.
Good modern lenses purchased.
Pentax FA 50mm F1.4
Sigma 105mm EX F2.8 Macro
Samyang 8mm Fisheye F3.5
. I've never had a decentered all metal lens going back to the seventies, I still have a few all are perfect.
Statistics will never be complete and we will only know of a small percentage of lenses sold, that's the reality, in the end I'm only interested in "the lens I have in my hand" not the statistical ones! I now have all the lenses I need, and am taking a permanent sabbatical from lens buying.
Let's hope that Sigma's promise of tighter quality control is a reality, so far I've seen very little of decentering in recent reviews of the art and their other series.
BTW. I hold Roger Cigala of Lens Rentals in very high esteem, he's doing a great job!