autoexposure lock question..

[smittymike19]

ok this weekend i was at my nephews bowling bday party. I wanted to shoot mynieces who were standing in a poorly lit area, but were infront of the lanes (which were very bright). what i did was turn the exposure up 2 stops. would i have been better off walking up to them so their faces consumed the whole screen, pressed my ae lock button walked back to where i was shooting from, recomposed and shot? or since i was shooting in raw it didnt matter since i can adjust this all in ps? i am curious as i am just ge:confused: tting a handle on all of this.

[slin100]

If you have a EX flash, you could have bounced the light from it off of the ceiling, assuming the ceiling was not too high. I generally dial in an extra +2/3 to +1 stop of FEC to counteract the tendency of Canon's flash system to underexpose on their DSLRs.

If you don't have an EX flash, you should get one! :-) Otherwise, I probably would have used the built-in flash with +2/3 FEC and shot in M or P mode and ISO 400. The background lighting on the lanes is probably not worth capturing. It's usually a sickly green from the flourescent lights.

[smittymike19]

here is what happened....not horrible, but i would rather her be brighter than the lanes...I am on a NOFLASH kick lately. i guess ill ahve to figure out the fill in flash technique. does this mean ill ahve to hack my rebel? i cnat adjust teh flash output manually, can I?

[Jon]

Taking a close-up meter reading on them would have been safer, but you seem to have gauged the exposure difference between the lanes and where everyone was. I wouldn't rely on bailing yourself out via RAW if there's another way of getting proper exposure. It makes correcting for errors easier than with JPEG, but the results of a correctly-exposed shot will still be better. The sensor has a finite dynamic range and if you're trying to salvage an area that's too far to one end of that or the other, you're going to lose detail in the shadows/highlights because it just wasn't captured by the sensor. Once it's gone, it's gone.

Yes, in situations like this a fill-in flash is a good idea. The pop-up flash on the DR can't be manually adjusted though. With the wasia/undutchables hack you'll get FEC, allowing you a measure of flash control with that or the 420EX. With the 550EX or 580EX you'll get FEC as part of the flash. The latter two also support manual flash mode and variable power levels.

[PhotosGuy]

Why make this hard? Shoot on "M".

[Jon]

Why make this hard? Shoot on "M".

He still needs to know how to meter for it. That was the crux of his question. Meter the scene and use some Kentucky windage or take a close-in meter reading of the primary subject?

[PhotosGuy]

He still needs to know how to meter for it. I guess I over simplified. He said "but i would rather her be brighter than the lanes" which, to me, means you have to start out with a constant, the exposure for her face if he stays with, "a NOFLASH kick". Which would mean zooming in/walking closer to get the exposure. Using M would "hold" the exposure set.
If he decides to "figure out the fill in flash technique." then it's a whole new can of worms. In that case, I'd read the exposure for the background, set M a stop underexposed, & adjust the flash for her face. Since you can't set the exposure of the rebel flash in the cam, he'd have to use neutral density gells to get the fill where he wants it, or zoom in while backing away to effectivly reduce the flash output on the subject.
Whether it's to hold a constant exposure on the face, or the background, M is where I'd start.

[slin100]

Judging from the picture, I think you did alright by guestimating a +2 EC. You probably came close to what the camera would have metered had you took a close-up reading of her face.

As to M mode, it certainly does hold the exposure, although you have to set it. There's nothing wrong with doing this, but there are alternatives. Taking a close up reading and using AE lock, works, too.

Neutral density gels aren't going to do you any good in this situation, when using the built-in flash. Flash metering is TTL, so covering the flash will simply make the flash work harder to achieve the desired exposure, unless you're relying on the ND gel to overwhelm the pathetically weak built-in flash. That's not something I'd rely on. FEC is really the only effective form on control. Lacking FEC on a 300D is certainly a handicap. It's up to the owner to enable FEC with one of the various hacked firmware. Personally, if I think a 550/580EX would be a far wiser choice. A tiltable, shoe-mount flash is an awesome lighting tool.

[PhotosGuy]

Flash metering is TTL, so covering the flash will simply make the flash work harder to achieve the desired exposure, unless you're relying on the ND gel to overwhelm the pathetically weak built-in flash. That was the idea. Not perfect, but it would work.