Canon 350D/Flash/Light Meter Readings

kenmc

Hi all, was out in a jungle recently trying to capture nightime pictures of sleeping birds etc, and basically I couldn't trust a single thing the light meter was saying to me - was telling me I needed to have around 25/30 seconds of exposure, with the (built in) flash, to get a shot! WTF? I was getting fine shots after trial and error at 1/200 upwards, but it really pissed me off that I couldn't trust the light meter - meant a lot more trial and error than normal.

Does the camera have any idea how to account for the flash in the dark? Is there anyway to make it less of a trial and error process? Any tips and tricks you can provide?

Cheers
K

Fajitas!

Were you using the onboard flash?

kuroino

kenmc, if you only need your main object to be well lit, use M (manual exposure), set shutter speed to high enough value and apperture to the value corresponding to the depth of field you need.

otherwise (if you only use an internal flash of the camera) you must keep the shutter open for longer to grasp some background lit by some other (natural?) light sources. That what the camera does in the A (apperture priority) mode for example. Because in your case you had very little natural light available, the camera kept the shutter open for very long.

I hope you know that in both cases the flash light works for much shorter time than the shutter is kept open, yes?

kenmc

Thanks for the replies, but I don't think my question was well phrased given the answers I've received.

What I really wanted an answer to was why was the light meter telling me that at eg f/5.6, and 1/100, I'd be way underexposed, even though I had the flash up, it had done a flash burst for the auto-focus anyway, and the picture came out totally fine, despite the light meter's protestations? Does it not know that the flash is up, and take that into account? I could of course understand if the flash was down that it would look for 30+seconds of exposure in pitch darkness to get a shot in, but I would have expected it to know it was using the flash (similar to how it knows it needs the flash in Macro, [], etc modes, pops it up and still takes the pictures ok)

kuroino, what you described is exactly as I did, except that the "high enough" shutter speed took a bit of time to find at times - not so nice when you're flashing your light at a sleeping bird until the levels are right.

Cheers
Ken

kuroino

> What I really wanted an answer to was why was the light meter telling me
> that at eg f/5.6, and 1/100, I'd be way underexposed, even though I had the
> flash up, it had done a flash burst for the auto-focus anyway, and the picture
> came out totally fine, despite the light meter's protestations?

The flash during autofocus is not for the exposure estimation purposes, but for the purpose of highlighting the object, as autofocus does not work well in badly lit scene.

> kuroino, what you described is exactly as I did, except that the "high
> enough" shutter speed took a bit of time to find at times

So you did it right. Nothing to worry about. The thing is that during the normal flash fotography your exposure is measured by the pair "flash intensity"/"apperture", instead of "shutter speed"/"apperture". So the shutter speed is irrelevant to the extent.

As for "high enough" shutter speed it is easy (in basic situation at least) - just set it as high as it is possible. And using flash on your camera it must be something like 1/250.

What I am trying to say is that it is nothing wrong with the cammera's lightmeter showing "underexposure". The actual metering of light required for flash fotography is carried out during the shot by E-TTL and does not affect the shutter speed, but the intensity of flash light as I said above.

At least that is my understanding on how it works on Canon EOS.