That's exactly right, in the case of the Tamron the "normal" (non Macro) focus range is from just under 1.5m to infinity, which is roughly a 1/4 turn, about the same as say FA 35/2. I've never been fortunate enough to try the FA 100 Macro, but would imagine it is similar. If it's anything like the FA 135/2.8 it would be very fast.
John ________________________________________ From: pdml-boun...@pdml.net [pdml-boun...@pdml.net] On Behalf Of John Sessoms [jsessoms...@nc.rr.com] Sent: 02 May 2010 00:29 To: pdml@pdml.net Subject: RE: limiter thingee.. [Scanned][Spam score:8%] From: "Tanya Love" > I just saw all of the techo talk on the other thread about a recommended > portrait lens and references to the FA 100m/2.8 macros, which I have, thanks > to Steve, just been enabled with. > > Can someone put all of this stuff into fairygirl speak for me? Just what > does that limiter thingee do anyways? What I understood is: For a LONG THROW Macro lens like the FA100/2.8, *IF* the auto-focus has to hunt & goes all the way to infinity and back to closest focus and then to whatever the subject distance is, it takes a LOOOOOOOOOOONG time getting there. A Focus limiter limits the range over which the lens can hunt - instead of going from closest focus to infinity and beyond, you can "limit" the range over which it is allowed to hunt for focus - say between 1.5 meters and infinity or such. It can hunt through this limited range much more quickly than it can through the entire focus range. Apparently most of the long throw is in the last bit going down to closest focus. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
