bouncing flash and reduction in stops

[reactan]

HI,

everytime i read about bouncing your flash, be it off the ceiling, with a bounce card or with the omnibounce, theres always "loss in stops".

Does this mean that everytime i bounce a flash, i have to adjust the increase the exposure (over that metered by the camera) to get a correctly exposed picture?

Thanks,
Al

 

[Ian]

You'll only have to worry about it if you are using a flash in manual control mode. In any of the TTL or automatic modes the flash or camera will take control and ensure correct lighting power is supplied.

One thing to note however, you can loose 2-3 stops when bouncing of ceilings and this greatly reduces the effective range of your flash. Also the bounced light takes on the colour of the material it's bounced off.

Ian

 

[reactan]

You'll only have to worry about it if you are using a flash in manual control mode. In any of the TTL or automatic modes the flash or camera will take control and ensure correct lighting power is supplied.

One thing to note however, you can loose 2-3 stops when bouncing of ceilings and this greatly reduces the effective range of your flash. Also the bounced light takes on the colour of the material it's bounced off.

Ian

great ! thanks...but i'm curious, how on earth is the camera going to know if i'm bouncing the flash, and what angle, distance to bouncing surface etc....all these variables add to the loss in flash "power" right?

 

[ydanz]

great ! thanks...but i'm curious, how on earth is the camera going to know if i'm bouncing the flash, and what angle, distance to bouncing surface etc....all these variables add to the loss in flash "power" right?

My best guess is the flash detects you are bouncing when it is being positioned at an angle other than 90 degress .... correct or not?

 

[reactan]

My best guess is the flash detects you are bouncing when it is being positioned at an angle other than 90 degress .... correct or not?

yes, i've thought abt that, but there's still the factor of the distance to the bounce surface.

 

[mpenza]

great ! thanks...but i'm curious, how on earth is the camera going to know if i'm bouncing the flash, and what angle, distance to bouncing surface etc....all these variables add to the loss in flash "power" right?

There's no need to know for the camera to know.

TTL mode:
the camera "sees" the reflected flashlight through the lens and determines when the flash exposure is enough and cut off the output.

Auto mode on the flash:
the sensor on the flash "sees" the reflected flashlight and determines when the flash exposure is enough and cut off the output.

 

[reactan]

There's no need to know for the camera to know.

TTL mode:
the camera "sees" the reflected flashlight through the lens and determines when the flash exposure is enough and cut off the output.

Auto mode on the flash:
the sensor on the flash "sees" the reflected flashlight and determines when the flash exposure is enough and cut off the output.

ic ic...thanks a lot to all who replied! :thumbsup:

 

[clive]

great ! thanks...but i'm curious, how on earth is the camera going to know if i'm bouncing the flash, and what angle, distance to bouncing surface etc....all these variables add to the loss in flash "power" right?

the answer is here:

You'll only have to worry about it if you are using a flash in manual control mode. In any of the TTL or automatic modes the flash or camera will take control and ensure correct lighting power is supplied.