Project: The time of day.
Exercise: Cloudy weather and rain.
For this exercise, I photographed the same scenes in sunlight and under cloud. The white balance was set to sunlight/daylight. The subjects chosen were a building, a person, and a street scene. These pairs of images were put together and the number of f-stops' difference between the sunny and cloudy versions was noted. Also I looked to see whether there was a colour difference.
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5636.jpg; F13; 1/250s; Sunny |
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5660.jpg; F9.5; 1/60s; Dull |
For each reduction in aperture, the amount of illumination entering the camera halves. This is because the area of the circular opening is halved. Also the same effect is achieved through each change in shutter speed. In practice, one stop down to a slower speed accompanied by one stop down to a smaller aperture makes no change to the exposure.
In this pair of images there is a difference of 4 stops due to shutter speed and 2 stops due to aperture. This gives a total difference of 6 f-stops.
The image in dull light is slightly bluer than the image in the sunshine. I prefer the image taken in the bright light because the form of the objects in the scene are better defined.
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5628.jpg; F8; 1/180s; Sunny |
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5608.jpg; F8; 1/20s; Dull |
The exposure difference between the two images is 6 f-stops. I prefer the image created in the dull light as the model's features are softer and there are no severe shadows.
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5636.jpg; F13; 1/250s; Sunny |
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5660.jpg; F9.5; 1/60s; Dull |
The exposure difference between the two images is 6 f-stops. I prefer the image created under the bright light because the form of the building is better defined.
When clouds cover the sun, the shadows are softer and the shadow edges less distinct. The subject is more evenly lit but not so definitely "modelled" - it looks flatter, with a less obvious form.
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White Tree Flowers |
This image was created under dull light. The subtle colours and textures are clearer under subdued light than they would be under bright light.
Next I took 3 photographs outdoors, on an overcast day, that make good use of the enveloping, shadowless light.
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5621.jpg; F8; 1/125s; Cloudy Conditions. |
The shadowless light in this image has allowed the fine relief on the thorn branch to be seen clearly.
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5618.jpg; F8; 1/90s; Cloudy Conditions. |
Here the different textures can be clearly seen under the subdued light.
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5612.jpg; F8; 1/60s; Cloudy Conditions. |
The strong colour of this flower is seen to good effect in the shadowless light.
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5639.jpg; F9.5; 1/60s. |
Rain drops on a black car bonnet.
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5651.jpg; F8; 1/60s. |
Rain drops caught in a spider's web.
What have I learned from this exercise?
The exposure difference between a photograph taken in bright sunlight and under cloud is approximately 6 f-stops. Images created under cloud are very slightly bluer.
Photographs of people and brightly coloured objects are often better when created under overcast or cloudy conditions.
Rain can produce interesting visual effects, so poor weather does not forbid the taking of good images.
For each reduction in aperture, the amount of illumination entering the camera halves. This is because the area of the circular opening is halved. Also the same effect is achieved through each change in shutter speed. In practice, one stop down to a slower speed accompanied by one stop down to a smaller aperture makes no change to the exposure.