How to correctly focus and recompose? (Canon 500D)

[pakyooh]

I'm still in the process of learning how to use my Canon 500D. I'm trying to get a better understanding of how to focus and recompose.

Given scenario would be a portrait shot. I focus between the eyes, the camera confirms its focused (beeps and the green light is lit in the view finder). Should the light stay light on when I recompose or would it disappear and it is safe to assume that it is still focused on the correct area?

Mods, sorry if I'm posting this in the wrong area.

[sfisher]

I'm going to assume you haven't done anything with custom functions and/or back-button focusing. I think the green light only comes on in One Shot AF mode, so I'll assume that what you're using.

When you half-press the shutter button the AF system starts and, when it's locked on, the camera will beep, flash the focus point red and turn on the green focus confirmation light in the viewfinder. The focus will stay locked as long as you hold your finger on the shutter button.

If you take your finger off the shutter button the green focus confirmation light will go off. The focus will stay the same while you recompose, but the next time you press the shutter button to take the shot, the AF system will start up again and refocus the lens.

So technically if the green light goes out the lens will still be focused on the same point you chose, but it will refocus before you take the shot.

The technique I would use is:
Compose the photo as you want it
Decide which focus point is closest to the point you wish to have in-focus.
Manually select that focus point.
Hover this focus point over the point you want to have in-focus and half-press the shutter button.
Without releasing the shutter button, recompose and fully press the shutter button to shoot.

Hope that helps!

[pakyooh]

Thanks for your response!

The focus confirmation actually does work even when I'm focusing manually.

I did forget to mention that I do hold down the shutter button half way, get a confirmation that its focused then recompose while still half-pressing. Sometimes the confirmation stays lit, sometimes it doesn't.

Sorry to ask but what custom functions were you mentioning and what is back-button focusing?

I'm learning everything online right now. I've recently joined workshops and meets so I'm trying to pick up as much as I can.

Thanks again!

Originally Posted by sfisher

I'm going to assume you haven't done anything with custom functions and/or back-button focusing. I think the green light only comes on in One Shot AF mode, so I'll assume that what you're using.

When you half-press the shutter button the AF system starts and, when it's locked on, the camera will beep, flash the focus point red and turn on the green focus confirmation light in the viewfinder. The focus will stay locked as long as you hold your finger on the shutter button.

If you take your finger off the shutter button the green focus confirmation light will go off. The focus will stay the same while you recompose, but the next time you press the shutter button to take the shot, the AF system will start up again and refocus the lens.

So technically if the green light goes out the lens will still be focused on the same point you chose, but it will refocus before you take the shot.

The technique I would use is:
Compose the photo as you want it
Decide which focus point is closest to the point you wish to have in-focus.
Manually select that focus point.
Hover this focus point over the point you want to have in-focus and half-press the shutter button.
Without releasing the shutter button, recompose and fully press the shutter button to shoot.

Hope that helps!

[Jim Bryant]

In your camera's menu you'll find custom functions. You change change the focus from the shutter button to one of the button on the back of the camera. Well, at least, that's what we do when using the pro series EOS1D's to 5DMK2's. I'm not sure about the Rebel series.
You got a manual didn't you? Look up custom functions or do a google seach for Canon 500D custom functions.

[Mr Guy]

Originally Posted by pakyooh

Thanks for your response!

The focus confirmation actually does work even when I'm focusing manually.

I did forget to mention that I do hold down the shutter button half way, get a confirmation that its focused then recompose while still half-pressing. Sometimes the confirmation stays lit, sometimes it doesn't.

Sorry to ask but what custom functions were you mentioning and what is back-button focusing?

I'm learning everything online right now. I've recently joined workshops and meets so I'm trying to pick up as much as I can.

Thanks again!

When you focus, you focus at a specific distance. That distance remains the same as long as the autofocus doesn't activate again. The confirmation light will illuminate when the shutter button is halfway depressed and the autofocus point is over something at the appropriate distance with a texture that the camera can focus on. If you focus and recompose, the confirmation light doesn't mean anything after you recompose -- it's just saying that when you re-aimed the lens, the autofocus point just happened to land on something else that happens to be in focus.

You can tell your camera through custom menu options not to focus when you press the shutter button and only focus when you press a different button on the back of the camera (Often labeled AF, but sometimes it's the OK button, depending on camera make and model). That lets you use the shutter button without having to refocus and keep whatever you intentionally focused on, but you do have to train yourself to use the focus button, and watch out for confused people who happen to borrow your camera!

[pakyooh]

Thanks, I did search that on google after posting. And found my way to that menu.

Originally Posted by Jim Bryant

In your camera's menu you'll find custom functions. You change change the focus from the shutter button to one of the button on the back of the camera. Well, at least, that's what we do when using the pro series EOS1D's to 5DMK2's. I'm not sure about the Rebel series.
You got a manual didn't you? Look up custom functions or do a google seach for Canon 500D custom functions.

[pakyooh]

Thank you, thank you, thank you!

That's exactly the explanation I was looking for.

Originally Posted by Mr Guy

If you focus and recompose, the confirmation light doesn't mean anything after you recompose -- it's just saying that when you re-aimed the lens, the autofocus point just happened to land on something else that happens to be in focus.

[Doug Pardee]

Originally Posted by pakyooh

I do hold down the shutter button half way, get a confirmation that its focused then recompose while still half-pressing. Sometimes the confirmation stays lit, sometimes it doesn't.

There are only two reasons that the confirmation light should go out once lit:
1) You are letting off of the shutter button, losing the lock.
2) You are using AI Focus AF and the camera thinks that the subject has started moving.

Okay, a third reason: you pushed the shutter button down and took a picture. But I think you'd know if that happened.

I recommend never using AI Focus AF. If you're using focus lock and recompose (which is what your question was about), select One-Shot AF.

[sfisher]

Originally Posted by pakyooh

Thanks for your response!

The focus confirmation actually does work even when I'm focusing manually.

I did forget to mention that I do hold down the shutter button half way, get a confirmation that its focused then recompose while still half-pressing. Sometimes the confirmation stays lit, sometimes it doesn't.

Oh, manual focus! That explains it. If you're in MF and the focus confirmation light is on, then your chosen AF point (or the one the camera chose if you're in auto AF point selection) will be in focus.

Sorry to ask but what custom functions were you mentioning and what is back-button focusing?

I think Jim answered that, but just to let you know, on my 400D I set Custom Function 4 to [3] AE/AF, no AE lock. In that mode, the '*' button on the rear of the camera activates the AF, metering and IS (when applicable). The half-press on the shutter button will still activate metering and IS, but not AF (nor focus confirmation if you're in MF).

I'm learning everything online right now. I've recently joined workshops and meets so I'm trying to pick up as much as I can.

Thanks again!

You're welcome! Enjoy the learning!

[FrankLamont]

The * button will lock it in (focus) if you set that in the Custom Functions.

It varies from Rebel to Rebel, but basically just have a look through there and find 'AF/AF lock, no AE lock'.

It just means you focus by halfway depressing the button and it will lock in when you press the * button.

Personally I don't like using the * button to focus, is all.