Difference between ISO and shutter speeds

[beesparkle]

COULD ANYONE EXPLAIN TO ME PLEASE THE DIFFERENCES WITH ISO AND SHUTTER SPEED. I AM NOT ALTOGETHER WHAT THEY ARE AND WHAT THE DIFFERENCE IS BETWEEN THEM. R THEY JUST DOING THE SAME THING?
I AM GETTING QUITE CONFUSED OVER WHAT I CHOOSE TO LET THE LIGHT IN!
AND ENLIGHTEN ME LOL
:rolleyes: MANY THANKS

[paulcheah]

shutter speed is the amount of time a shutter remains open thus regulating the amount of light allowed to fall on the film/sensor


iso is the sensitivity of the film/sensor towards light.
higher iso = higher sensitivity to light

[RossW]

Beesparkle,

paulcheah's reply is correct, but let me amplify it a bit. ISO does indeed refer to the sensitivity of the image sensor (or film in the pre-digital days) to light. Real old-timers in the U.S. like me might even refer to is as the even older term "ASA speed." That terminology gave rise to referring to a film as being "fast" or "slow" when speaking of it's sensitivity to light. A "fast" film might have an ISO rating of 400, 800, 1600, etc. It doesn't require as much light to record an image, and therefore the shutter speed of the camera can be faster (open for a shorter time) and/or the lens opening can be smaller. Likewise, "slow" ISO speeds (25, 50, 100) indicate less sensitivity to light, requiring slower shutter speed (longer exposures) and/or larger lens openings.

The downside of higher (faster) ISO ratings in both film and digital imaging is increased graininess (film) or noise (digital) in the image.

[beesparkle]

Thanks for the advice RossW its slowly starting to come together but veerrrrrryyyyy slllloooowwwwlyyyyy with me lol.... thanks again :lol: