every camera user community I've been exposed to... seems convinced that their lenses are at least as good if not better than the other brands.
I noticed it also. It goes farther. On one Minolta group, for example, I noticed that people took for granted that multi-coating was invented by Minolta and used since remote times on their lenses. I think they extrapolated from the fact that Minolta began to use a two-layer process (two coats of the same material applied with different thickness) in 1958.
(...) There seem to be several possible explainations for this.
2) ...there is very little difference in quality between comparable lenses from all the manufacturers.
I think it's true that differences are small. And that manufacturers had a large part of their line comparable with others'. For example, I though until last week that Pentax famous low distorsion (0.5%) 28/3.5 lens was unique in that respect but discovered that the MC-Rokkor-X 28/3.5 had the same low distorsion figure.
Increasingly, manufacturers are tailoring optical quality more precisely to price class as they learn not only to engineer quality in but also to engineer it out.
Still, sometimes you feel a manufacturer has put a bit more for the price, hoping to sell volumes of that item. This could be true of the Olympus Stylus with the great 35/2.8.
Andre
