One of the best rules I ever learnt was the Sunny 16 rule and I thought I would share. I was out shooting with a friend in Long Island City, New York and I forgot to bring my light meter. I was shooting on a Norita 6×6 without an inbuilt light meter on slide film, so no need to tell you how important the exposure accuracy was. My friend Dan just said use the Sunny 16 rule, you’ll be right. Yes, you would be correct to assume he is another Australian working in New York.
What is this magic rule that magically gives me correct exposure by eye? Well it turns out that if you look at the sky and can see if it is overcast or sunny you can figure out which exposure to use fairly accurately.
This is how it works:
Look at your film stock, this is also your shutter speed.
Bright and hazy with visible shadows you set your aperture to F11
Overcast with slight shadows you set your aperture to F8
Completely overcast with no shadows, you set your aperture to F5.6
Got it? Sounds confusing? Well here is an example:
It’s sunny and my film stock is 100 then according to this chart I need to shoot at 1/100th of a sec at f16. Of course you can change things as long as you stick to the basics. Because I am going to shoot some friends playing footy I am going to make my shutter speed 1/200th instead of 1/100thto freeze the action a bit more. This means that I am going to lose 1 stop of light so I need to change my f stop from F16 to F11 to compensate for that. Anyway I made a little chart to help explain it further.
I also got these nice weather jpegs from MelsBrushes at http://www.melsbrushes.co.uk/shop to help illustrate my chart.
Thanks Dan for saving my Bacon that day. You can see my very talented friend’s work here: http://www.danrootphoto.com/
If you still want to be totally accurate, then check out this link and get yourself a light meter: http://www.hypop.com.au/accessories/light-meters.html These guys seem to have really good prices on the Sekonic range which are the ones I highly recommend.
I hope this was helpful.