Author Topic: Limiting auto focus hunting  (Read 4240 times)

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Offline ronny

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Limiting auto focus hunting
« on: April 25, 2011, 03:48:27 PM »
Here is the issue,
Focus on moving, jumping, flight prone subjects examples birds insects etc.
They move to a non photo settings, behind leaves, branches etc.
Release shutter button, Ah! missed shot.
Re focus and lens racks all the way out and in or does not focus on subject, subject gone!
Happens even if you prefocus location.

Here is what I found to help fix this problem......


If your camera does not have focus lock (a100) but has DOF button.

After following subject press hold the DOF button and shutter locks along with lens focus settings.

Follow subject to new location and release DOF button after pressing shutter button down half way.
( this works even if you set camera down for hours).

Pick camera up and point to subject, press DOF button and then shutter half way.

The focus and setting pick up right where you left off.

Have not read about this technique any where. I did find it by accident.

This of course in lew of AF/MF button and you do not want to manual focus.

Any comments are always welcome.

ronny (Ron)








Sonya700, A100, Sony CZ 16-80 3.5, 50mm 1.7, 24mm 2.8, 60mm Macro 2.8  100-200mm Af, 70-210mm beercan, 75-300mm Af, 500mm F8, Tamron SP300f-XI 2x, Tamron 200-400 LD if, several Minolta flashs

Offline Clive

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Re: Limiting auto focus hunting
« Reply #1 on: April 29, 2011, 03:41:31 AM »
Thanks ronny. I think I followed that...sort of...or not. ;)

And this works for the models with no FL then? But I am having trouble understanding this part, "The focus and setting pick up right where you left off." Not sure I follow that...since there is a new subject at a different focus point. Can you help me with this?

Thanks. 

Clive
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Offline ronny

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Re: Limiting auto focus hunting
« Reply #2 on: April 29, 2011, 07:41:28 AM »
Sorry for the confusion, my post was kinda long winded.
I have tried this on a700, I think any Sony camera that has a DOF button should work.

Lets say the last focus point was met.

1.  I press the shutter button half way and DOF button. Camera locks focus and apature.
2.  Take photo.
3.  Release shutter an then DOF button,
4.  Point in new location, press DOF button first, then shutter half way down.
The focus seems more often to just pick up the auto focus from there and not rack out and back hunting. Of course it has to have something close by to focus on.  This has worked on subjects that are say 6" to 8" difference. 

I can't wait to try this with birds in flight.  If its even possable.

Hope that helps clear up the confusion.

added.. It seems that this will work on cameras that have DOF button only.  5D,7D a100, a700

ronny

« Last Edit: May 04, 2011, 05:42:35 PM by ronny »
Sonya700, A100, Sony CZ 16-80 3.5, 50mm 1.7, 24mm 2.8, 60mm Macro 2.8  100-200mm Af, 70-210mm beercan, 75-300mm Af, 500mm F8, Tamron SP300f-XI 2x, Tamron 200-400 LD if, several Minolta flashs