It limits the focus range. My DFA 100 macro doesn't have one so I can't be too precise but if IIRC, if you are in the close-in focus range and engage the limiter, it keeps the AF search for focus within that close-in range. If you are in a far-off range, the limiter keeps the AF from trying to focus down to close in. All of which reduces the search time. As others have alluded, one feature of macros is that the helix gearing in the focusing mechanism is designed so that you get very slight focus changes with a movement of the focal ring - it is much less sensitive than normal lenses and this makes it easier to do fine focus. The downside is that it takes more turning to move from minimum distance to infinity, and the limiter is a way to compensate.
stan On Apr 30, 2010, at 9:26 PM, Tanya Love wrote: > 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? > > Tan.:) > > > -- > 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.
