Saturday, November 22, 2008

Snowfall

We had our first significant snowfall on Thursday, all day.
I started to recall exposing for snow scenes since I spent a significant amount of time reading on the topic last winter. In brief, cameras are calibrated to expose for photos assuming every object in the world reflects 18% of the light they receive regardless of TONE. While snow is white - a very, very, very, very light tone - it also reflects 36% of the light hitting it. This plays a trick on the camera: it detects twice the amount of light intensity and changes its exposure to obey the 18% rule; but what you end up with is a -1.0 stop (a halving of light) underexposure and 'grey' appearing snow. To fix this, in any snow covered scene: change your metering to Spot, point the camera at a patch of snow and either increase your EV (exposure compensation) by +1.0 stop or in Manual mode change your shutter speed so that the light meter indicator is about 3 steps towards highlights from the centre. If you don't have Spot metering, still point your camera at the snow and change your exposure as above. All the other tones in the scene will fall into place and snow will appear a nice BRIGHT crisp white!

Here's some first attempts for the season:

 

3 comments:

Espère Reed said...

You are so technical. :P I read and just nod along... Hahaha...
Great pics (along with the other ones from your previous posts)! (Y)

Jarrett E Hather said...

Annie :D

Haha yes, admittedly I am a bit of a perfectionist. It makes me want to better myself all the time and 'find out' things :)

Jarrett E Hather said...

Ok reworded now, haha I try :P