06-10-2010, 11:33 PM
[quote name='Pinhole' date='09 June 2010 - 01:49 AM' timestamp='1276040965' post='355']
I second that! A very informative post - thanks, Wim!
I don't want to hijack the thread either, but ... I have only ever used the centre focus point and recomposed on (analogue + digital) SLRs. It's probably due to me starting off with rangefinders that I never got into all that - and I've gradually switched to an almost totally manual-focus lens range on my DSLR.
Is there any real advantage to using the multiple focus points except the convenience of not having to re-frame the shot? Would it be beneficial to 'learn' to use this feature?
[/quote]
Thank you for your kind words!
Officially, focusing and recomposing is not a good idea, certainly not from a theoretical POV. With dslrs the effect is worse too, because effectively dslrs have less DoF than analog cameras have (0-sensor thickness vs 0.2 mm film thickness).
However, I must admit I do this all the time, although I often either use MF after AF, or use a point that is as far from the camera as my subject. And if you actually use small apertures, it generally doesn't matter all that much anyway. Don't forget that AF with fast lenses is only specced to be within 1/3 of DoF, and slower lenses only within DoF. I used to do centre MF with MF analog cameras, because it was more convenient to use the centre wedge for focusing than anything else, except fro macro of course: it would eb too dark. For macro I used a very finely ground matte focusing screen, for accurate MF. In a way you can compare that to the -S type of focusing screens (EE-S, Ef-S, Eg-S) for Canon bodies.
It certainly is useful to learn other ways of using AF IMO, for the simple reason that one should know its tools well, to use them optimally. I often find that when I learn something new about a subject, and practice with it, it means I can use it, and it extends my arsenal of tricks.
HTH, kind regards, Wim
I second that! A very informative post - thanks, Wim!
I don't want to hijack the thread either, but ... I have only ever used the centre focus point and recomposed on (analogue + digital) SLRs. It's probably due to me starting off with rangefinders that I never got into all that - and I've gradually switched to an almost totally manual-focus lens range on my DSLR.
Is there any real advantage to using the multiple focus points except the convenience of not having to re-frame the shot? Would it be beneficial to 'learn' to use this feature?
[/quote]
Thank you for your kind words!
Officially, focusing and recomposing is not a good idea, certainly not from a theoretical POV. With dslrs the effect is worse too, because effectively dslrs have less DoF than analog cameras have (0-sensor thickness vs 0.2 mm film thickness).
However, I must admit I do this all the time, although I often either use MF after AF, or use a point that is as far from the camera as my subject. And if you actually use small apertures, it generally doesn't matter all that much anyway. Don't forget that AF with fast lenses is only specced to be within 1/3 of DoF, and slower lenses only within DoF. I used to do centre MF with MF analog cameras, because it was more convenient to use the centre wedge for focusing than anything else, except fro macro of course: it would eb too dark. For macro I used a very finely ground matte focusing screen, for accurate MF. In a way you can compare that to the -S type of focusing screens (EE-S, Ef-S, Eg-S) for Canon bodies.
It certainly is useful to learn other ways of using AF IMO, for the simple reason that one should know its tools well, to use them optimally. I often find that when I learn something new about a subject, and practice with it, it means I can use it, and it extends my arsenal of tricks.
HTH, kind regards, Wim
Gear: Canon EOS R with 3 primes and 2 zooms, 4 EF-R adapters, Canon EOS 5 (analog), 9 Canon EF primes, a lone Canon EF zoom, 2 extenders, 2 converters, tubes; Olympus OM-D 1 Mk II & Pen F with 12 primes, 6 zooms, and 3 Metabones EF-MFT adapters ....
