[EMAIL PROTECTED] wrote:
>Good AF is much faster than manual focusing. Hence with moving subjects I
>get much more sharp pictures than with manual focusing (unfortunately my
>medium format set is manual focusing while my Nikon gear is AF).
I don't doubt it is much faster, but how accurate is it? I am sure it is
generally more accurate for action but some people nearly always use AF.
>Additionaly, I found AF to be more reliable in low light situations than
>MF.
I haven't found this to be the case for me, but if it works better for you
then use it.
>Maybe I get wrong impression cause I'm comparing AF on 35mm equipment
>and MF on medium format equipment (viewfinder in medium format is always
>dimmer because there are just a few medium format lenses with 35mm lens
>speed, i.e. f/1.8. In medium format you are happy if you can get 2.8 lens
>speed, especially with telephoto lenses).
>Anyway, if you know how to use auto-focusing (there are some tricks,
>especialy in portrait photography) AF is faster and more convenient than
>manual focusing.
What tricks are those? How can you really get the camera to pick a relatively
small spot (one much smaller than the AF area) on a three dimensional subject
that isn't particularly contrasty or not the closest point on the subject to
the camera? That is generally the situation that I encounter in my photography.
I have used spot AF on my N90s in an attempt to get it to focus
on what I REALLY want to focus on and I have better success with manual focus for
non action. For action, AF is certainly superior. I have shot action with
manual focus but I will get a much better hit rate with AF. I remember one
time photographing some birds in flight using my N90s's focusing tracking for
the first time. I really didn't have faith it would work but it did. Of course
I didn't always get optimal focus (i.e. on the bird's eyes) but I don't expect
to under the circumstances. I certainly would not get optimal focus for a
bird in flight with manual focus unless I was really lucky. But for static
subjects, I have found AF to be inferior to manual focus.
>And last but not least. Nobody can notice difference in auto or manual
>focusing in photo by photo comparation.
If I look at a given photo and _critical_ focus is missed, of course I can't say
whether AF was used, the photographer was sloppy, or the subject moved a bit.
However, I definitely get a higher percentage of critically focused photos
with manual focus than with AF for static subjects.
I have noticed the difference and that is why I generally shoot in manual focus.
When I first got my N90s, I usually shot AF. I noticed that too often it
missed critical focus on eyes (using spot AF, AF lock, recompose and shoot).
If this was due to field curvature of my lenses (all Nikkors including some
with good reputations like the 80-200/2.8 AFD new, 20/2.8 AFD, 85/1.8 AFD,
35/2.0 AFD) then AF is still less effective than AF for static subjects since
I have an N90s and not a multi AF point camera like the F5 or F100.
I really can see the difference between a roll shoot with AF and a roll shot
with MF. Last Christmas, I got lazy and shot it all AF. That roll is noticeably
less sharp in general than when I manually focus. It isn't way off. Non picky
people or people not familar with what my lenses can do would be satisfied.
But I know what my lenses can do and I know they can do better than what I
generally get when I use AF with static subjects.
AF certainly has it uses and is clearly superior to manually focus in some
situations, but I don't believe that it comes anywhere close
to replacing manual focus, at least not if one of your goals is that your photos
be the sharpest they can be and not just "good enough".
BTW, whenever I hear the phrase "good enough" in the context of photography,
it is usually not "good enough" to me. My mother thinks her $50 Vivitar
point and shoot takes photos whose sharpness is "good enough". Believe me,
that particular camera is even bad for a p&s IMO.
David Johnson
