Exposure Compensation ?

[jlpk007]

what does it mean when people said set it to "1 stop" or is it "FUll stop" ...??

i usually set my exposure compensation to +2 in night shoots.../indoor(poor lighting)...to get a slower shutter speed....is it the right way??

ps:my cam has no manual control

 

[Snowcrash]

The easiest way of thinking.

The camera had a bulit-in metering mode to judge the correct exposure. Sometime it can be fooled by Black or White Objects occupying a big part of the picture. (Black Cat or Snow etc)

So you compensate to get what you want. For Black Cat to look 'Black', -1 stop etc.

For snow, +1 stop etc.

 

[clive]

i usually set my exposure compensation to +2 in night shoots.../indoor(poor lighting)...to get a slower shutter speed....is it the right way??

the metered exposure value (the suggested combination of aperture &shutter speed, that is) is usually ok to get a decent(read: not too over exposed nor too underexposed) picture. by always setting +2 stops for night shots, i believe your night shots r overexposed. that is, assuming that it is not those "tricky" situations like what snowcrash mentioned.

of coz, u can always bracketing the exposure, then pick the shot with the degree of brightness/darkness that suits your style.

eg. metered value is f5.6, 1/30s. suppose u fix the aperture 2b used, then choosing 1/15s will compensate +one stop. likewise choosing 1/8s will compensate +2 stops

 

[farbird]

what about using something called gray card to lock the exposure settings first?

the metered exposure value (the suggested combination of aperture &shutter speed, that is) is usually ok to get a decent(read: not too over exposed nor too underexposed) picture. by always setting +2 stops for night shots, i believe your night shots r overexposed. that is, assuming that it is not those "tricky" situations like what snowcrash mentioned.

of coz, u can always bracketing the exposure, then pick the shot with the degree of brightness/darkness that suits your style.

eg. metered value is f5.6, 1/30s. suppose u fix the aperture 2b used, then choosing 1/15s will compensate +one stop. likewise choosing 1/8s will compensate +2 stops

 

[hammer_400]

dunno bout wat grey card....
but exposure compensation can be used for other stuff.....
like a few weeks ago, took some photos in bright sunlight
with my relatives...
if juz shoot, there would be lotsa shadows on thier faces, so i got them to move into da shade...
den i adjust exposure compensation -1.3 ev, so the background would'nt be overexposed, set the flash compensation + 1 ev, and shoot....
came out nicely exposed....

 

[johnyu]

what about using something called gray card to lock the exposure settings first?

Meters which are built-in in the cameras are called reflected light meters. They measure light reflected from the subjects. (For comparison: a type of handheld meters is incident light meter which has a white dome and measures light hitting the dome coming directly from the light sources.)

All reflected meters assume the average brightness of the overall scene is same as the brightness of a midtone grey card placed in the same light setting. (Technically, a midtone grey card is called 18% grey. The "18%" is in logarithm scale.)

So, if you have a tricky scene which consists of, say, mainly white subjects, the meter will be "fooled". One option to get correct exposure is to dial in compensation, to tell the meter how many stops the subject is off from midtone grey. Another option is to place a grey card in front of the camera to do the metering, set the aperture/shutter according, then take the photo.

[p.s. Ok, there're actually some more complications when you take into account the latitude of the medium (e.g. film or CCD) and zone system -- mapping the actual grey scale in the scene into the desired grey scale in the final image. But that's beyond the basic...]

 

[johnyu]

what does it mean when people said set it to "1 stop" or is it "FUll stop" ...??

i usually set my exposure compensation to +2 in night shoots.../indoor(poor lighting)...to get a slower shutter speed....is it the right way??

ps:my cam has no manual control

The concept of "stops" has nothing to do with exposure compensation. (On the other hand, compensations are specified in unit of stops.)

A stop is a unit of measurement of relative brightness. Similarly, you can adjust your aperture or shutter speed up/down by how many number of stops to cater for scenes with different brightness.

Finally, in general, you don't need to dial in a +2 compensation to take night shots.