Getting frustrated with AF...I know it's me doing something wrong, but what is it?

[markubig]

Hi all -

I am using a 300D and have it set to automatically choose from the 7 AF points. That being said, when I take a picture (mostly of people) I move the closet AF point to my subject(s) eyes/collar/hairline (whever there is some form of contrast) and hold the shutter halfway to let the AF kick in. A lot of times, the other AF points will blink and focus on something behind or on the side of my subjects . . .

Am I doing something wrong? Is there a more efficient way to focus on a subject?

Do any of you manually choose a focus point? I was even thinking of manually choosing the center focus point.

I'm just getting frustrated because it sometimes causes me to miss a priceless pose or expression.

Thanks for your help!

[Persian-Rice]

Stop using the auto AF point? I dont think I have ever used that. 90% of my shots are shot with the center position, the rest are custom.........

[cactusclay]

Yea, I just use the center one as well, focus on an eye, keep the shutter button half way depreesed, re compose the shot and shoot it.

[griff2]

Use a single focus point only. It can be the centre one, or if you want to focus off-centre, any of the others.

[Persian-Rice]

Not sure if the rebel has this, but seperate the AF and exposure buttons. Not sure if the rebel can do this, check you Custom Functions. That way you can lock exposure and refocus as much as you want.

[Littlenose]

I too choose the centre focus point, and occasionally move it around manually when it makes it easier [meaning i don't have to recompose]

I was wondering however how you all manage to take pictures of things by remote control when you want something in the corner of the frame to be the focussed object and the rest to be out of focus? This i struggle with and would appreciate some help.

[cactusclay]

Manual pre focus.

[markubig]

Thanks all. I guess I'll switch to the center AF point and see how that works . . . so is there ever a time when you all feel the need to use the Auto AF?

[cactusclay]

NO, not me, but mabey for shotting sports.

[cactusclay]

where's that dang spell check?

[Littlenose]

Manual pre focus.

heh heh, guess i was being for too lazy.... thanks for that kick up the butt.

[Paul_B]

I've had the same trouble, and didn't know/understand why it did that. Using AF, with my 2 kids 5 feet from me, it would sometimes focus the back of the room an add'l 5 feet away. I didn't get to see this until I d'l onto pc.
Two kids out of focus, back of the room behind them in perfect focus.

Gonna do the way you all suggest from now on. A question tho.

If you want your subject off center, say to right side of a the frame. Would it be best to use manual center focus, press half way, recompose and shoot.
Or just manually choose the right focus point.
Maybe they both attain the same thing, but if there is a "right" way of doing it for best results, I'd like to know.

[scottbergerphoto]

Not sure if the rebel has this, but seperate the AF and exposure buttons. Not sure if the rebel can do this, check you Custom Functions. That way you can lock exposure and refocus as much as you want.
The un hacked Rebel lacks Custom Functions.
Scott

[HJMinard]

If you want your subject off center, say to right side of a the frame. Would it be best to use manual center focus, press half way, recompose and shoot.
Or just manually choose the right focus point. Maybe they both attain the same thing, but if there is a "right" way of doing it for best results, I'd like to know.

It somewhat depends on the contrast of the scene and which metering mode you're utilizing ... because when you lock focus (and metering) and then recompose you're changing the scene from what the meter "saw". Sometimes that's what you want ... sometimes not. If your camera has the custom function allowing the metering and focusing locks to be routed to separate buttons ... problem solved. The DRebel does not have that capability.

There really is no negative to switching your focus point away from center ... whatever you're comfortable with ... just keep in mind where the camera is locking exposure.

[scottbergerphoto]

Canon reccommends not using Focus and Recompose, but rather using the AF point closest to your subject. The reason being that as you recompose your subjects distance from the camera changes and you lose the sharpest focus.
Here is a good explanation:
Why Focus-Recompose Sucks (http://visual-vacations.com/Photography/focus-recompose_sucks.htm)
Scott

[markubig]

Canon reccommends not using Focus and Recompose, but rather using the AF point closest to your subject. The reason being that as you recompose your subjects distance from the camera changes and you lose the sharpest focus.
Here is a good explanation:
Why Focus-Recompose Sucks (http://visual-vacations.com/Photography/focus-recompose_sucks.htm)
Scott

so i guess i should get used to adding AF point adjustment into my pre-shot routine?

[Titus213]

I am also new to the digital arena, the DRebel being my first digital. Question about focus point - using flash would it make more sense to shift the focus point used rather than use center focus and recompose? Will the flash follow the focus point used?

[CyberDyneSystems]

Thanks all. I guess I'll switch to the center AF point and see how that works . . . so is there ever a time when you all feel the need to use the Auto AF?

The only time it makes sense is when you are trying to use all the AF points for fcus tracking of a moving subject...

However,. the 300D and 10D with only 7 focus points spread out too far on the screen were never very good at this sort of thing.

Thus a single focus point is pretty much allways better.

[Steve Parr]

I've been shooting local bands lately, and one of my biggest problems is that the microphone stand will be in perfect focus. The singer? Not so much. I've been doing a lot of manual focus, and that seems to get the job done, but I'm going to figure out this whole auto-focus thing if it kills me...

Steve

[René Damkot]

I've been shooting local bands lately, and one of my biggest problems is that the microphone stand will be in perfect focus. The singer? Not so much. I've been doing a lot of manual focus, and that seems to get the job done, but I'm going to figure out this whole auto-focus thing if it kills me...
First, take a look here (http://www.pbase.com/image/18920257)
After that, make sure your cameras AF is correctly calibrated. If the camera is okay, practice! ;)

[Steve Parr]

First, take a look here (http://www.pbase.com/image/18920257)
After that, make sure your cameras AF is correctly calibrated. If the camera is okay, practice! ;)

Maybe it's just that it's 4:30am...

How do I go about deciphering that?

Thanks!

Steve

[Mark_48]

Does the use of a single AF point speed up the focus process since there are less points to evaluate or is the difference if any negligable?

Mark..........

[scottbergerphoto]

Does the use of a single AF point speed up the focus process since there are less points to evaluate or is the difference if any negligable?

Mark..........
It reduces the tendency of the camera to hunt in low contrast situations and yes the difference is noticeable in low light.
Scott