user Qs

So its been a while since ive taken photos.

I have 2 questions.

Since I use the AF ON button to focus.

Do I have to keep holding it down (after it focuses) and then press the shutter?


On the same topic, I am using a flash (270ex & 580ex).

How do I take pictures with a flash?

When I press the flash button (for the flash to measure the neccessary output)..

Do I press the flash test button, then focus then shutter?

Or do I focus, then flash button then focus then shutter?

What I do is monotonous and tiring. I focus then press the flash button then focus again then shutter.

CorruptedPhotographer wrote in post #10447369
So its been a while since ive taken photos.

I have 2 questions.

Since I use the AF ON button to focus.

Do I have to keep holding it down (after it focuses) and then press the shutter?

How you use the focus button can vary with the AF mode you are using. If you are in One Shot AF then pressing the button locks the AF -- you hear the beep and see one or more focus points light up. You can then let up with your thumb or just take the shot -- either way your AF will stay locked unless you re-press the button. So, you can press the button and recompose if you want and then press the shutter button to get the shot.

AI Servo AF is a mode in which the camera will continue to refocus while the button is pressed, which is for use while the subject is moving. If you let up on the button the camera stops focusing. So you can still use it to focus and recompose if you just let up on the button after you see it achieve focus (there is not focus lock, no beep, no lit focus points).

I'd avoid AI Focus AF -- it's supposed to "intelligently" switch between AI Servo and One Shot if it detects subject motion, but has a bad rep in doing this properly.

Your EX flashes should work automatically -- you don't have to press any other buttons than just your regular focus and shutter release buttons. The Test button on the flash is simply a test button. There is a "modeling light" function with flashes but in general just focus and shoot. If the camera has a hard time focusing the flash will emit a focus assist beam if you are shooting in One Shot AF so you can get the focus and then you can shoot.

Yes, I am using the setup where one button on the back is the middle focus point and the other is variable (where I choose it to be using the multil point controller).

Yes, familiar with AI Focus and AI Servo. Thanks for explaining it.


I dont mean the test button on the flash, I mean the one on the camera body.
Man its been a while since I've taken pictures.

Ive tested with my 270EX. If I simply focus then take the picture, the exposure will not be as good had I pressed the flash test button then taken the picture.

CorruptedPhotographer wrote in post #10447793
Yes, I am using the setup where one button on the back is the middle focus point and the other is variable (where I choose it to be using the multil point controller).

Yes, familiar with AI Focus and AI Servo. Thanks for explaining it.

I dont mean the test button on the flash, I mean the one on the camera body.

What camera body are you using? I'm not aware of a "flash test" button on a camera -- on cameras with a built-in flash there is just a "flash on" button, at least the ones I'm aware of. Now, the 7D has some new stuff and maybe other newer cameras.

Well, I'm not familiar with the 270EX. What does the manual say in regards to shooting with the flash in Auto/ETTL mode?

The two flashes I have are the 430EX and the 580EX. They emit a focus assist beam, and they have a "preflash" that lights/meters the scene for the flash use. It is normally not noticed, though, unless you are in Second Curtain and have a slow shutter speed.

Also, what shooting mode are you in? There are differences between M, Tv and Av in how the flash is used in ETTL mode. Auto and P mode let the flash light up the scene, but you may need to fine tune things in the other modes.

im using the 5d mkii.

Its the flash exposure button. When you hit it, it flashes and measures the necessary output.

CorruptedPhotographer wrote in post #10447888
im using the 5d mkii.

Its the flash exposure button. When you hit it, it flashes and measures the necessary output.

OK, I'm stumped. I see on the 5D2 a Flash Exposure Compensation function and a Flash Exposure Lock function, but as far as I know neither of these work as you describe.

What does your camera manual say about the function of this button?

hi Tony.

Its on the back, called

FE Lock

Pressing it fires the flash, then focus, then take the picture.

Ah, I see what you mean -- I never use the FEL button! Its actual function is to lock the flash exposure on the subject so that you can, say, set the flash then recompose. But it does emit a flash to actually get the proper exposure. It's not needed if you keep the subject in the same orientation, but if you are getting better results when you use it, it's up to you -- either use it or try using Flash Exposure Compensation.