Thanks to everybody who responded. I have some further comments and questions.
> Joseph Tainter > The poor autofocus performance in low light is not because of the lens. > It is because of the poor autofocus performance of Pentax DSLRs > (those produced so far) in low light. I am comparing its AF performance with other lenses attached to the same DS body. What I find about this D-FA is that almost always it makes at least 4 iterations of the motor (i.e. forward-backward-forward-backward) before it locks the focus. Even my Tamron 70-300 4-5.6 set at the focal length of 100mm does not do this in the same light condition. And that is far inferior lens. (Tokina ATX PRO 28-70/2.6-2.8 is even faster, but the focal range is different, so it is not a fair comparison). Herb, since you have this lens, - I was wondering if your D-FA lens: 1) is also assembled in Vietnam (it is written at the bottom of the barrel) 2) the hood is also loose on the lense 3) does 4 runs when AFocusing in a relatively low light (say, 1/10-1/60 at 2.8 at ISO 100) even on subject with a good contrast? Thank you, Igor > Date: Wed, 23 Nov 2005 19:40:01 -0500 > From: "Herb Chong" <[EMAIL PROTECTED]> > To: <pentax-discuss@pdml.net> > Subject: Re: brief impressions of Pentax D FA Macro 100 F/2.8 > > i have both the D-FA and FA 100/2.8 macros. for the work that i like to do, > the main factor in choosing the D-FA over the FA is whether i am going out > in the field and have to walk far or not. the FA is so much heavier that i > usually don't go outside with it. also, the manual focus override while in > AF mode makes for much more convenience in the field. i also like the lens > hood. so far, i haven't noticed any difference between them. if there was > more of a difference, i would choose the sharper one to carry, even if it > weighed more. > > Herb....
