Sunday, June 15, 2014

Exposure w/o Metering - Part 6

Today was a mixed bag of light, i.e. very clear and also cloudy skies, in sometimes rapid succession.
Hence, I went out to photograph the shadows. I was talking about in the last post. What the day did not provide me with, at least not during the time I was hunting shadows, was a full (bright) overcast. Of the 3 promised conditions, we are therefore missing one.

Down to business. You will see that my subject will not deserve a place in a gallery, however, I believe several effects of bright sunlight versus light overcast can be easily demonstrated.

The first image refers to shadows cast by unobstructed sunlight. When this short of shadows can be seen, the sunny 16 rule applies, i.e. stop down to f/16, shutter speed = s/ISO.
hard light (direct sun) casting sharp shadows and a high contrast image

The second image show sunlight shining through a thin layer of clouds. This is the condition when you want to open up the aperture to f/11.
soft light (light clouds) washing out the shadows
You might notice that the upper image has a much warmer overall tone. This is actually created by the dominance of the direct sunlight over the blue-sky ambient light. In the second image, the ambient light starts to take over filling the scene with blue light, hence the colder color tone.

Another thing to learn here. the total amount of light present in the shadows (in theory) is identical and caused only by the ambient light, i.e. the blue sky. Why did a write in theory? Very simple, in real life reflections, e.g. from buildings, cars, etc., can occur. It is fair to say, I believe, that in the above images, real life meets the theory pretty well.

For techies under my readers, the following remark. Both shots are taken with the X100S in aperture priority, so that the images are technically correctly exposed. Also, I used RAW files, thereby preventing color temperature correction influencing the outcome.

Finally, for the f/8 condition, just imagine that there is no shadow cast at all, and all you see is pavement and dirt, even more blue-ish.

Concluding, to understand the illumination, watch the shadows!

No comments:

Post a Comment