Focus on Clouds

By André Costantini

The thing about sunsets is that light changes quickly. Just moments apart can appear to be worlds of difference. What can be interesting about that time of day is what the light does and how it's severe angle can create dimension and depth to things like clouds, not to mention the intense colors.

I have always found it fascinating when your eyes try and watch clouds and you get lost in the softness of the texture, not quite being able to focus. And your camera's lens is not unlike your eyes.

Auto focus of your camera works by detecting contrast, if there is little or none, the auto focus may have trouble locking in on the subject. To avoid having to worry about focus and being able to concentrate on composition, all of these images were taken using manual focus.

Have you ever heard of the term infinity when it is referred to focusing? Every lens has an infinity focus point. This distance varies depending on the focal length of the lens you are using. This is the point where everything far away will be in focus. And clouds are generally far away. Far enough away that they are at infinity for our lens focusing purposes.

Because the focus point is tied to depth of field, if I focus my lens (in this case the Tamron 28-300) on infinity and my subject is entirely located at that distance, everything would always be in focus at any aperture. Then all I have to do is make sure my shutter speed is quick enough to get crisp images (somewhere between 250th and 500th of a second in this case.)

Once I have all of these technical things out of the way the "focus" can be on taking images, trying different compositions and catching the quickly ever-changing light. All of these images where taken over a span of only 10 minutes using various focal lengths with the Tamron 28-300mm.

300mm f6.3 1/500 ISO 400