flash exp. compensation

[ni-conartist]

while using the f100 and the sb80. ive noticed when using the camera

in slow sync mode to ensure proper background exposure...when i set

exposure compensation on the body it changes both on the body and the

flash. ive noted this by watching the distance scale change on the

flash while adjusting exposure compensation on the body. you can

adjust flash exposure compensation without affecting background

exposure(in slow sync mode), so why doesnt it work the other

wayaround. ?? i want to be able to overexpose my background(in slow

sync mode) while not over exposing my flash-lit subject. only way to

defeat this is to subtract the amount of compensation ive made on the

body from the flash. example: in slow sync i set plus one stop on the

body for the background, it also adds one stop to the flash exposure,

to combat this, i set -1 stop on the flash units own exposure

compensation setting.

 

any other easy way around this besides just throwing the camera in

manual and adjusting settings so the background exposure is one stop

over? why cant u set ambient exposure compensation without affecting

the flash output. very annoying.

 

never trust a Niconartist

[david_h._hartman]

There comes a point where second guessing and over riding automation is more trouble than it�s worth. It�s probably going to be easier switch to manual to control the background exposure. You will probably find your results are more predictable using manual flash power also. You can focus, set the power level 1/1~1/16 so the LCD matches the focus distance noted or use a flash meter (assuming an SB-24~28 or 80). It sounds like you�ve got your options figured out pretty well. I�m not aware of any custom settings on either the F100 or F5 that will do what you want directly.

 

The majority of users would likely find exposure compensation for ambient light that does not effecting the flash more than annoying. This would require setting the camera and the flash separately to the same value in many situations. A lot of mistakes would be made.

 

Check your manuals. If you don�t have manuals you can order then from Nikon for about $10.00 ea. plus shipping. You might also like the Magic Lantern Guides for you camera and flash.

[scott_blair1]

Exposure compensation does not magically select the background and ignore the subject. It adjusts the exposure, period. It's as if you switched to slower or (in your example) faster film. How could it NOT affect flash exposure?

[ni-conartist]

because the exposure for the background and subject can be controlled independantly, thats how. thats the whole purpose of slow sync and "balanced fill flash". thats what the balanced part means. balancing the background exposure with the flash-lit sibject. for instance, when i shoot cityscapes at night i get the best results opening up 2 stops over the metered exposure. say i now want to ad a person in the forground to my cityscape shot. i want to over expose the background 2 stops. but i dont want the flash to over expose my subject 2 stops. see my dilema? the f100/sb80 combo will over expose both by setting the exposure compensation on the body, not only will it increase ambient exposure two stops but will also increase the flash output 2 stops as well. leaving a blown out subject. to overcome this i have to either select -1 stop on the flash's exposure compensation scale, or put the camera in manual and adjust my settings till i get a two stop overexposed reading. both of which will leave the flash to expose the subject in the proper 18% gray normal/average exposure.

[angel_o.]

Desmond,<br><br>

for overexposing the background 2 stops just add +2 stops exposure-compensation on the camera and -2 stops flash-compensation for not overexposing the foreground.<br><br>

Exposure compensation on the camera controls the total amount of light exposing the film, flash comp. controls only the flash-output. Therefore, if you want to overexpose the background in dim light-conditions and don't want to overexpose the foreground with the flash-light, you have to increase the exposure and reduce the flash-output. <br><br>

Have fun shooting!

[ni-conartist]

yup, figured that..just wondered if i was missing something. thanks

[ed_alban]

<i>...so why doesnt it work the other wayaround. ?? i want to be able to overexpose my background(in slow sync mode) while not over exposing my flash-lit subject... </i>

<p>That's because the flash output depends on the meter inside the camera body (located at the bottom of the mirror box). If you fiddle with the meter, you affect both ambient and flash readings. If you fiddle with just the flash, you're just telling it to put out less (or more) than what the camera meter will tell it to.

<p>Another way around your "problem" (it's not really) is to use manual metered mode on your camera and lower your shutter speed from the recommended reading however many stops you want the background exposed. The beauty of this lies in the fact that the shutter speed does not affect flash exposure, only aperture does (remember the GN formula?).

[ni-conartist]

yes thanks, the latter method is fine for posed shots when i have the time. so i guess its just easier to subtract the amount from the flash that i added to the ambient exposure. thanks