Too slow Paul... On 11/21/06, Paul Stenquist <[EMAIL PROTECTED]> wrote: > Will it work with the A400/5.6, or is that lens too slow? > On Nov 21, 2006, at 5:23 PM, John Francis wrote: > > > > > On Tue, Nov 21, 2006 at 07:56:25AM -0700, Joseph Tainter wrote: > >> With >200mm lenses, however, the AF is not good for anything but > >> fine-tuning your manual focusing. > >> > >> ----- > >> > >> Thanks, Jostein. You may have just saved me some money. For bird > >> photography, my manual focusing just isn't fast enough. I need AF. > >> > >> Joe > > > > The problem with using the AF adapter with long lenses is that it > > only covers part of the range - you have to pre-focus to somewhere > > in the approximate distance of your subject. > > > > Most of the time I use it on the back of my 300mm, and have had > > no problems with the limited focussing range. In fact I see it > > as an advantage; if the camera guesses wrong on the focus, and > > winds all the way to the end stop before going back the right way, > > this is much quicker with a restricted focussing range (after all, > > the high-end lenses from other manufacturers have switches for this). > > > > But if you can rough-focus to where you expect to be using the > > lens the AF is fast - often faster, in fact, than a real AF lens. > > I've found it to be perfectly satisfactory. This (*ist-D) shot: > > > > http://panix.com/~johnf/temp/justin.jpg > > > > was taken with the AF adapter on my 300mm/f2.8 Note the lack of > > DOF (even at an effective shooting aperture of f10), but the auto- > > focus was quite capable of doing its job. > > > > A drawback, admittedly, is that you are restricted to only the > > central AF point. This may, or may not, be a problem for you. > > But if it would work for you I recommend getting one; it's the > > best bang-for-the-buck item in my camera bag. > > > > > > -- > > PDML Pentax-Discuss Mail List > > [email protected] > > http://pdml.net/mailman/listinfo/pdml_pdml.net > > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net >
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