Ken,
As always I appreciate your glimpses over the "inside". What I find most interesting now is the hint to the build costs (point 2). I suspect a major contribution to the cost was due to having to maintain very low tolerances and this perhaps is associated with manual assembly in the now closed Japan factory(?). Anyway, a friend recently disassembled several FA consumer zooms and was horrified to find out large tolerances by design, alignment through shimming as a rule, high wear plastic guiding rails - all of these easily leading to misalignments of moving optical groups, both relative to the optical axis and the image plane. Optics that are rather good delivered sub-average or inconsistent results mainly due to poor mechanical design and manufacture. It's hard to believe that Pentax might apply the same cost reduction to the DFA macros - traditionally some of their best lenses - but I cannot help wondering if common and molded parts policy sufficed to lower the production costs enough to make the goods profitable.
Servus, Alin
I'm not quite sure what you are meaning by "alignment" but shimming is an absolutely standard way of assembling anything to tight tolerances. It would be impossible, within the confines of retail budgets, to build something in any quantity to the tolerances required of a lens without some method of providing adjustment during assembly. Given the other assembly points you mention, I wonder why they bother shimming during assembly, though.....
KT> BTW, I read an interesting statement by a Pentax lens designer on new DA KT> macros. I list only on DA 100mm macro.
KT> 1. It is a brand new design (as opposed to 50mm version which basically KT> purged flare spots (kind of ghost) caused by CCD. Otherwise no changes for KT> 50mm), taking into consideration the future reduction of the barrel size. KT> FREE design contributed to the significant reduction of the size.
KT> 2. FA100/50 macros have been one of the most well selling lines of Pentax KT> lens lineup, but they were also money losers (cost was higher than the KT> price). The more they sold, the more did they suffer from red :-).
KT> 3. Therefore, they now use many common parts and injection molded parts, KT> whereby they should make money while maintaining the price points.
KT> 4. They swear that the performance was not compromised.
KT> Re above item 1 (future reduction of barrel size), I noted that the filter KT> size of this lens is 49mm vs. current 58mm. Return to more like M series KT> lenses?
KT> Re above 4, this was uttered in rather an informal occasion and I have every KT> reason to believe that this was true (not a propaganda).
KT> But to me, the size of the new DA macros is as important as their optical KT> performance.
KT> Cheers,
KT> Ken
