Originally posted by wlachan The last time I disassembled Sigma lenses were a decade ago, and back then their inner structures were poor against Pentax lenses, and that was the reason why so many Sigma lenses self-destructed.
I'm not arguing that but that was a decade ago. Sigma has changed a lot in recent years.
EDIT: I just came across another post of yours in which you write:
I have bought, owned or come across DA14 (x2), FA*24, FA31 (x2), FA43, FA77 (x3), FA100/2.8, FA135 (x2), FA*200/2.8 (x4), DA10-17, DA16-45, DA18-55. Among these, DA14 (x1), FA31 (x1), FA77 (x2), FA100, FA135 (x2), FA*200 (x3) were physically defective (not counting AF or optical defect). Hard to believe really.
And you believe Sigma lenses are even worse than that?
EDIT: I just remembered that Dpreview went through
three copies of the DA* 55/1.4 and couldn't get one that didn't have a tilt in the focus plane. Not exactly a role model performance regarding quality control.
I'd like to be a fan of the DA* 55/1.4 (it was designed by Jun Hirakawa, the designer of the FA 77/1.8) but I think its bokeh is too distracting most of the time.
Originally posted by wlachan The EX finish, rubber, ball bearing and contact pins all worn within a very short period of time.
Is that your personal experience? With which lens?
I have two Sigma EX lenses and haven't observed any of this. Admittedly, I treat them well and haven't owned them for decades yet.
Originally posted by wlachan Sigma lenses are being cheaper for good reasons because they cut corners in every little details.
I'm not sure they cut corners in every little detail. The aperture blades of my Sigma 28/1.8 close so much more nicely than those of my Pentax FA50/1.4. The latter show jaggies until about f/2.8. None of this with the Sigma and the symmetry is perfect. In another thread you don't deplore the (alleged) discontinuation of the FA50/1.4 because you've seen copies fall apart. I think that this is an exaggeration too but I agree with you that the built-quality of the FA50/1.4 is not superior to Sigma EX lenses, on the contrary.
Third-party lenses have to be cheaper (or significantly better) in order to be competitive against OEM equipment which is the first natural choice for everyone.
Originally posted by wlachan However, Sigma has never had trouble developing sharp optics, even though with poor flare control and colour rendition.
Colour balance might be different for some lenses but I never heard anyone call the colour rendition "poor". I'm sure I could pull out a lot of reviews testifying great flare control for Sigma lenses, however, this is not my fight.