Technically, this is the very same D FA lens as before but with changed exterior styling and different aperture design.
It uses the same optics, it has the same quick-shift focus, it has the same focusing mechanism, and it performs like the previous versions. But it has added WR and new aperture design, oh and new material for the exterior.
It is not called DA Limited because it is too big for being a DA Limited.
It is not called D FA Limited because such a thing does not exist.
It is not called DA Star because it is weather resistant, not weather sealed (WR is a simpler form weather protection) and it doesn't have SDM!
It is not called DA because in essential it is the same lens as the previous D FA and consumers would only be confused by a new name for what is essentially the same lens!
And it is not called D FAJ, because 'J' in Pentax terms means 'junior' and is an entry level beginner lens. The 100 Macro is not entry level beginner. The FA J's had plastic lens mounts and was overall very, well, plastic. This D FA is metal!
I don't understand why a D FA must have an aperture ring...
Now, with the FA Star 200 f/2.8 becoming DA Star 200 f/2.8, there are many more changes, not only the lack of aperture ring.
DA Star has new focus mechanism, and double AF systems. Also new exterior. Added weather sealing (not weather resistant). Only the optical formula is the same as the previous FA Star, but with a newer version of the SMC coating. So, there are many more differencies between FA Star 200 and DA Star 200 than between new and old D FA 100.
About the design being inspired by the DA 35 Limited, well why not? It is logical to me that the Macros from Pentax shares some design elements to keep a consistent design. It may very well be so that all future primes from Pentax will have a similar look, and be WR.
The DA Star 55 and 300 were both especially developed for APS-C, according to Pentax. The DA Star 55 is the APS-C version of the FA Star 85. Both has new optical formulas, not a re-use of older formula. That is why they are called DA and not D FA. Also note that D FA lenses doesn't have double AF systems as the DA Stars have and the D FA WR isn't weather sealed as the DA Stars, just weather resistant.
Last edited by RMabo; 12-09-2009 at 11:48 AM.