What is Sunny 16 rule?

Damn!! I forgot that light meter..does that sound familiar.
A beautiful landscape is waiting in front of you to be clicked and you are left with your imagination on how to expose that frame.
Well..sunny 16 rule comes handy.

What is Sunny 16 Rule?

On a brightest sunny day the exposure is roughly equal to the reciprocal of your film speed or ISO setting (in case of digital slr) at f/16.

i.e. your shutter speed = (approx) film speed

so if you are loaded with a 100 ISO film then set your shutter speed to 125
and if you are loaded with a 200 ISO then your shutter speed would be 250 basically anything close to the ISO numbers.

Well, now what if it is not exactly that sunny.
Hmm..not to worry we can tweak this rule a bit to work for us.

If it’s slightly overcast then we need more light to expose so we open it up one stop (I mean the aperture) keeping the shutter speeds same as above.
so for 100 ISO film it would be shutter speed = 125 and aperture f/11.

If it’s slightly more than overcast then we shall open it up a little more..2 stops.
so we get for 100 ISO film, shutter speed = 125 and aperture f/8.0

and for the rest of the ISO’s you do the math.

Happy Clickin.