BetterPhoto Q&A
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Blue Sky

Thanks, Julie

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September 29, 2000

1. If you are using a Skylight filter, remove it. It will make the sky paler as it filters out some of its blue. If you are using a UV filter you might try removing it. The effect of a UV isn't as much as a Skylight, but since film responds to "low" UV just above the visible spectrum, it will remove a slight amount of blue also. I use a UV a lot outdoors, and its affect on clear blue sky is slight.

2. Next time you're out on a clear day, look at the sky carefully for where it contains the most and least blue. You will notice that the sky is paler nearer the horizon, washed out more in the direction of the sun. It is also darker higher in the sky, especially opposite of where the sun is. This means in the morning, the western sky will have more blue, and in the afternoon the eastern sky will have more blue. Try shooting earlier or later in the day away from the sun (with the sun at least somewhat behind you) if you're shooting more toward mid-day. Smog and haze will also make a sky paler.

3. Exposure can also affect how blue the sky is. If you are shooting a very bright scene, a bright blue sky will end up darker (more blue) than a dimly lit scene requiring greater exposure. This is a tough to fix because you want a good exposure of your subject material which usually is not just the sky. See the next item for a possible fix.

4. If you are using an SLR, you can try a polarizer which will darken sky, but not in all directions. It has its greatest effect when looking at about 90 degrees (a right angle) to the sun, meaning the northern or southern sky in the morning or afternoon. At mid-day it doesn't have as much effect. Rotate the polarizer until it darkens the sky some. If your camera rotates the filter ring when focusing, or if it's a zoom and does the same thing when zooming, you will need to adjust it after focusing or zooming. If your camera has AF or is a recent model with TTL metering I recommend using a circular polarizer, not a linear one, which can throw AF off and newer metering sensor systems which are behind the mirror. Be careful when using a polarizer to darken a sky with a wide-angle lens. Since a polarizer only affects part of the sky it is very easy to end up with part of the sky darkened and the part of it unaffected because the angle of view is much wider. Evaluate the scene carefully when adjusting the polarizer for this possible problem. The shorter the focal length of the wide-angle the greater the risk of this (wider the angle of view).

I haven't mentioned film in any of the above. Different films have different saturation levels for blue sky and this can affect it too, but I'm presuming you want to stay with what you are currently using. Yes, you can use very high saturation negative film like Agfa Ultra 50, or slide films like Fuji's Velvia and Kodak's Elitechrome 100 Extra Color (professional version is E100VS). If there is any hint of blue, it will definitely show up on these films. However, these films also super saturate all colors, not just the sky. If you are doing portraits or people are very close in the foreground these films can produce unpleasant skin tones. The high saturation level also has the least accurate color rendition. Colors will be much brighter than they are in real life.

Hope this helps you out.

-- John

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September 30, 2000