Soft focus

donkeymusic said:
what backs button focussing?
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I don't know what your camera is but, there may be a custom function to assign focussing to a button you can operate with your thumb. That separates the focus from the shutter release and makes it easier to control when your camera focusses, therefore what it's focussing on.
 
Phil V said:
I don't know what your camera is but, there may be a custom function to assign focussing to a button you can operate with your thumb. That separates the focus from the shutter release and makes it easier to control when your camera focusses, therefore what it's focussing on.
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Ah, i dont think mine will have that function, will have a look but doubt it
 
HoppyUK said:
Doing as you've described is a sure way to miss-focus. Which is exactly what your OP pic looks like - it's just that it seemed very unlikely given the f/number.
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yeah, think i have got in a bad habit, need to re-assess the way i shoot and to also set up up the focus points
 
donkeymusic said:
yeah, think i have got in a bad habit, need to re-assess the way i shoot and to also set up up the focus points
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Quick google says your Sony a550 can do back-button AF, here http://forums.dpreview.com/forums/post/34282416

Suggest use centre AF point, and focus-recompose technique. Checking and rechecking focus is very important as there's often less depth of field than you might think, especially with head and shoulders when subjects are moving a bit, like leaning backwards and forwards etc, unless you're at a high f/number.

You need to know that focus-recompose can lead to inherant errors in some situations, but only when a) you're very close, b) the subject is positioned a long way off-centre, and c) you're using a very low f/number. It's an unusual combination of factors and unlikely to be a problem but just be aware.
 
HoppyUK said:
Quick google says your Sony a550 can do back-button AF, here http://forums.dpreview.com/forums/post/34282416

Suggest use centre AF point, and focus-recompose technique. Checking and rechecking focus is very important as there's often less depth of field than you might think, especially with head and shoulders when subjects are moving a bit, like leaning backwards and forwards etc, unless you're at a high f/number.

You need to know that focus-recompose can lead to inherant errors in some situations, but only when a) you're very close, b) the subject is positioned a long way off-centre, and c) you're using a very low f/number. It's an unusual combination of factors and unlikely to be a problem but just be aware.
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Ah, brill something else for me to test, not quite sure i get my head around what it does but will read the manual.

I have been using centre AF point but i think i was focusing then recomposing and forgetting about the focus thinking it was locked in.
 
donkeymusic said:
Ah, brill something else for me to test, not quite sure i get my head around what it does but will read the manual.

I have been using centre AF point but i think i was focusing then recomposing and forgetting about the focus thinking it was locked in.
Click to expand...

Default setting is the camera focuses every time you half-press the shutter release. Which is fine, but means it will refocus everytime you take your finger off/on again. This can make things hard/irritating, so switching AF to the back-button means the camera will only re-focus when you press that with your thumb. If you use focus-recompose technique, as most people do, it's much easier.

Check your depth of field here, so you know what you've got to work with http://www.dofmaster.com/dofjs.html
 
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