Re: DOF Debate

[P3D Dr. George A. Themelis <fj834@xxxxxxxxxxxxxxxxxxxxx>]

Reply to message from gjw@xxxxxxxxxx of Wed, 21 May

>Debate then ensued about whether the hyperfocal
>tables on various cameras provide sufficient sharpness (i.e. a
>sufficiently small "circle of confusion").
>
>This is one of the things we're discussing: when can this rule be
>successfully violated?  

There is another debate in my mind:  The hyperfocal focusing practice
ensures "sufficient sharpness" within its limits, without taking into
account the subject.  It has been argued that usually infinity objects (in
landscape photography) have smaller details than close-by objects and
require higher resolution.  Hence the advice to focus past the hyperfocal
distance (closer to infinity).

BTW, the author of this book (forgot his name already and was not aware
that he has a web site... I happened to get his book without knowing
anything about it) has something to say about the 1/3, 2/3 rule of thumb (I
believe he says that the 1/2 - 1/2 rule works better for object-oriented
focusing, but I might be wrong) and also for the DOF preview funtion of
modern SLR cameras (he says that it does not work - when you stop the
camera down you really do not see how sharp the objects will be recorded
in the film because of the way the screens works, but I'll have to check
the book again for specific details)

Now, regarding the question of how can the requirement for sharpness all
over the place be succesfully violated, I think a lot depends on
personal preferences too.  I have seen pictures where the out of focus
background was bothering me (just like Greg described, because I could see
details and kept distracting me) while other people commented (in SSA
folios) that they had no problem with the background and enjoyed the
picture.

-- George Themelis


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