Dragging the Shutter / Rear Sync Flash techniques?

[Illah]

I shoot a lot of low light and have recently started learning these techniques. Does anyone know of any general tutorials on this, or just have any general advice?

One thing that I come up against a lot is if I drop the flash down 1 1/2 to 3 stops under I get a much more balanced image, which is great for general ambiance. When I then take a picture of a person, the subject looks somewhat dark although well balanced against the background. If I bring the flash up to 0, or only 1/3 or 2/3 stop under, the subject pops out but the background is then really dark by comparison. Any ideas on how to balance it more while maintaining a poppy, well lit subject?

So far I've managed to get good pics by bumping up the overall exposure in post via RAW processing but this introduces noise.

--Illah

 

[Big Mike]

Every photo shot with flash is basically two exposures. One is exposed by ambient light and one is exposed by the flash...together they make up your image.

If the background has very little light reflecting off of it...it will take a lot of exposure...that will probably mean a fairly long shutter speed. The flash can quickly illuminate a close subject...but the light falls off very quickly.

Lets say you set your exposure for the background...and the shutter speed is very long....and you also fire the flash to illuminate your subject. This will work...but the problem is that you will also get an exposure of your subject from the ambient light...and because of the long shutter speed...any movement by the subject will cause blurring. The result will be that you have have a ghostly blur of your subject along with the sharp subject exposed by the flash.

 

[cumi]

A good example:

http://www.planetneil.com/faq/dragging-the-shutter.html

 

[Iron Flatline]

Thanks Cumi, that's a pretty helpful site.

 

[Dylan]

I agree. That guy obviously knows his stuff. it would be nice to aprentice with someone like that.

 

[Illah]

I actually already came across that site - it's very good for more than just these techniques! I've been toying with what I learned there as well as other things, but I'm still not getting what I want... I think I need a faster lens to really capture the background without a super-long exposure.

--Illah