airplanenut
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What Method For Focusing Do You Use?

Fri Oct 06, 2006 11:37 am

I've seen arguments for both continuous focus and single focus.

For continuous, apparently you can be just a tad out of focus and not have it fixed, and thus get a blurry shot.

With single focus, though, you can't shoot unless you're in focus, and I've had my camera reset when it was just slightly out of focus (go all the way out, then back into focus) causing me to lose shots. Additionally, you have to refocus if the plane moves.

What do you use, and why? I'm using a D70.

Jeremy
Why yes, in fact, I am a rocket scientist...
 
Fly747
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RE: What Method For Focusing Do You Use?

Fri Oct 06, 2006 12:04 pm

For planes I always use continuos focus. Single focus, like you said, you have to refocus everytime. In this mode however your focus can lock but by the time you take the actual photo the plane moves fast and you are left with an unfocused image. Thus I always use Servo AF.

Ivan
 
DC3
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RE: What Method For Focusing Do You Use?

Fri Oct 06, 2006 3:31 pm

AI focus (predictive auto-focus) on Canon. Because this can handle fast-moving subjects. I leave the camera set up like this more-or-less permanentsly and for stationary subjects I use the autofocus to get roughly in the right spot then fine-tune manually if necessary.

Other people get equally good results using other methods, so it's down to how you prefer to work.

Chris
 
viv
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RE: What Method For Focusing Do You Use?

Fri Oct 06, 2006 11:39 pm

Predictive autofocus works best with moving subjects.
Nikon D700, Nikkor 80-400, Fuji X Pro 1, Fujinon 35 f/1.4, Fujinon 18 f/2
 
Psych
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RE: What Method For Focusing Do You Use?

Sat Oct 07, 2006 12:11 am

Jeremy.

With my old 300D I got used to constantly pressing and re-pressing the shutter half way with my aviation photography, as it did not have AI Servo (continuous focusing) in Av mode.

But now that I have the 20D I use this all the time for moving aircraft, with the centre focusing point selected. I have found it completely reliable, which is a real relief. For anything stationary, I would tend to go back to 'One Shot'.

All the best.

Paul
 
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JeffM
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RE: What Method For Focusing Do You Use?

Sat Oct 07, 2006 12:12 am

Often I'll just use the old fashion 'zone focusing' method.
 
linco22
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RE: What Method For Focusing Do You Use?

Sat Oct 07, 2006 12:28 am

Quoting JeffM (Reply 5):
Often I'll just use the old fashion 'zone focusing' method

Jeff man i'll assume thats a manual method? I find with aircraft auto is ok. But I find I manual focus for alot of my stationary stuff. Its total control. Except when my eyes are getting worse  Wink

Regards
Colin  Smile
 
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JeffM
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RE: What Method For Focusing Do You Use?

Sat Oct 07, 2006 1:14 am

Quoting Linco22 (Reply 6):
Jeff man i'll assume thats a manual method?

Yup. Good old fashion manual focus. Simply put, you pre focus your lens on an object where you want to snap your moving object. When it passes that object..... "Click". You've got it. With the switch on most lenses it's easy enough to let auto focus make the initial 'lock', then just flip the switch to manual for the shot.

Not really needed with a slow moving, lumbering airliner, but with small targets such as militay jets, or close in objects like a race car, it can be very handy if you have the DOF to work with.
 
aviopic
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RE: What Method For Focusing Do You Use?

Sat Oct 07, 2006 3:19 am

Quoting JeffM (Reply 7):
Yup. Good old fashion manual focus. Simply put, you pre focus your lens on an object where you want to snap your moving object. When it passes that object..... "Click". You've got it. With the switch on most lenses it's easy enough to let auto focus make the initial 'lock', then just flip the switch to manual for the shot.

No need for that with a bit of modern equipment Jeff.
Simply override the auto focus which can be done on a number of lenses these days even when you are actually using the auto focus having the shutter button pressed it is possible to alter the focus manually.
The truth lives in one’s mind, it doesn’t really exist
 
linco22
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RE: What Method For Focusing Do You Use?

Sat Oct 07, 2006 3:45 am

I agree with Jeff here. I spent a day recently shooting a few sporting events and I wish i'd tried manual more. I got alot of back focusing. Not the lens, my fault. The camera is trying to differentiate between one object and another, but sadly the cam doesn't read your mind. I spent alot of time filling the frame so I was set at 200mm and didnt need to worry about zooming, just focusing.

But don't get me wrong i'm not that quick, so if I need to zoom in/out alot i'll go AF.

Regards
Colin  Smile
 
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JeffM
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RE: What Method For Focusing Do You Use?

Sat Oct 07, 2006 3:54 am

Quoting Aviopic (Reply 8):
No need for that with a bit of modern equipment Jeff.

True, good point, I just don't use that method enough.
 
aviopic
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RE: What Method For Focusing Do You Use?

Sat Oct 07, 2006 6:21 am

Quoting Linco22 (Reply 9):
The camera is trying to differentiate between one object and another, but sadly the cam doesn't read your mind.

It seems to me that this can only happen when you use automatic selection of your focus point Colin.
If so just select the focus point of your liking manual.

Quoting JeffM (Reply 10):
I just don't use that method enough.

That's the fun of photography, we are all doing things different and in our own way but with the same goal.
Which is the best we can and we are never done.
The truth lives in one’s mind, it doesn’t really exist
 
DC3
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RE: What Method For Focusing Do You Use?

Sat Oct 07, 2006 4:58 pm

There's a simpler way to turn autofocus on or off (on Canon equipment, anyway).

Programme the camera to focus when the star button is pressed, NOT when the shutter button is pressed (the shutter button becomes the exposure lock so, effectively, you are switching the functions of the two buttons). On all of my cameras (EOS10D, 30D and 5D) you do this via Custom Function 4 and the setting you need is option "1". Other models may be different so you need to check.

Now, when you press the star button the lens focuses and when you take your thumb off, it stops and you can re-compose if you need to. It's like having a focus lock in reverse.

You keep the lens switched to autofocus all the time but, if you want to focus manually, simply keep your thumb off the star button.

It takes some getting used to - practice first.

Chris
 
linco22
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RE: What Method For Focusing Do You Use?

Sat Oct 07, 2006 7:49 pm

Quoting Aviopic (Reply 11):
It seems to me that this can only happen when you use automatic selection of your focus point Colin.
If so just select the focus point of your liking manual

Hi Aviopic, centre point was set. So either down to me, which I think it is, of the lens/cam, which I doubt.

And thanks for that tip Chris, i'll check that out

Regards
Colin  Smile

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