Using dedicated Flash

[Partsrept]

This question is not about flash...i think.

Do not know

With my flash installed on a camera Canon XSI if i use P mode it will choose good setting for me: Shutter and Exposure Compensation. Exposure Compensation is always at 0.

When i go to AV or Shutter mode Exposure Compensation is alway -2. Why ?

What mode do i use with flash ? Do not want to use P or Auto.

Please help

[autofocus]

Originally Posted by Partsrept

This question is not about flash...i think.

Do not know

With my flash installed on a camera Canon XSI if i use P mode it will choose good setting for me: Shutter and Exposure Compensation. Exposure Compensation is always at 0.

When i go to AV or Shutter mode Exposure Compensation is alway -2. Why ?

What mode do i use with flash ? Do not want to use P or Auto.

Please help

is it doing the same thing with the flash removed?

[inkista]

With Canon, the flash and camera work differently depending on what shooting mode you're in. My guess is that the EV -2 setting in Av or Tv is because you set it that way, or you're shooting in such low light that you've hit the limits on the max. aperture of your lens, or 30s in terms of the shutter speed.

In Av/Tv modes, the assumption is that you're using the flash for fill. Typically, the camera will choose exposure settings more or less for the ambient light. Your ambient/flash balance is going to be mostly for ambient.

If you're in P, the assumption is that you're using the flash more for illumination and that you're handholding. In that case, your ambient/flash balance is mostly for the flash, and your shutter speed will never go below 1/60s.

The only way to get complete control of how the ambient and flash are going to be balanced against each other is to shoot in full Manual mode.

I recommend reading the "EOS Flash Photography Confusion" section of the "EOS flash bible".

You can use a custom function to force 1/200s as a shutter speed in Av mode to shift the balance more for flash, but you still won't have full control over the ambient/flash balance, as you would if you were shooting in Manual.

[Partsrept]

I just checked it again: With Cam on in P mode i have shutter 60 and F1.4. Exposure Comp is 0.

AV mode i cannot use it because Shutter speed is alway SO slow
In Shutter mode camera cannot select right F stop.

In M mode i can select same P settings Shutter 60 and F1.4 and with this settings Exposure Comp is "-2". To bring it back to 0 i have to slow my shutter speed. With this i see no purpose of using flash

Built flash works svery good and this Targus flash TG-DP38Cis not really good.
Is there a difference in quality of pictures with cheap and expensive dedicated flashes ?

[Partsrept]

thank you - i will read it right now

[Partsrept]

i prefer M mode too. But in my case i have to slow shutter speed to get right Exp Comp. i have to go below 1sec

[autofocus]

try stopping your lens down ...see what 5.6 yields

[inkista]

Ok, here's where your thinking is a little off. You don't have to "bring it back to 0".

The camera can only meter the light it sees. It doesn't "add in" the flash--the flash burst hasn't happened yet.

Go ahead and shoot at -2EV in Manual mode. All that means is that you're underexposing the ambient by two stops--the flash will add more light to the scene, and your subject will be exposured ok. It's only if you want the ambient light to register more strongly in the photograph that you'll have to find a way to increase it more.

And have you forgotten that you have a third setting to control ambient exposure? You can increase the iso...

There is no single correct set of exposure settings with flash photography. This is where your experience with ambient-only is leading you wrong. It's all a matter of how you want to balance the flash against the ambient. How much of the background do you want to see? If you want the background black and only your subject to register, than go ahead and add flash to -5EV exposure. Do you just want the flash to lift the shadows? Then shoot closer to what the ambient would require without the flash.

[barabe]

Very interesting post, I am struggling with my off camera flash and i will try your suggestions. Thanks.