How is a bounce flashes required power measured?

[asim18]

If I get a proper iTTL flash (sb-600) for my D40x, how does the camera measure power required for bouncing?

I assume you have to manually compensate, for example as a lower ceiling will mean a more narrow and intense light than a high ceiling which would give a wider spread and less intensity.

Or is everything metered automatically, no matter where you point the flash head?



Thanks

 

[xolotl]

It's all metered automatically as it measures the amount of light coming through the lens after the pre flash to calculate the full flash power.

 

[asim18]

It's all metered automatically as it measures the amount of light coming through the lens after the pre flash to calculate the full flash power.

Wow, that is damn awesome.

I've currently got an old fully manual flash and it's bloody annoying having to guess the power needed for bouncing.

Cheers for the quick reply.

 

[robmiller]

It's quite easy to fool, though, most often if you have something shiny that throws up a huge specular highlight and confuses the camera into thinking you have a bright subject.

 

[D.P.]

It's quite easy to fool, though, most often if you have something shiny that throws up a huge specular highlight and confuses the camera into thinking you have a bright subject.

true, but I was stunned at the plug and play ability of the SB-600.

 

[robmiller]

Yeah, don't get me wrong---it's a thousand times better than trying to do things manually (unless you have time and a good flash meter, I suppose). Just so long as people realise it's just as fallible as any other reflective metering