Shooting Sunstars

Shooting sunstars (sunbursts) is a natural in the southwest with its clear skies and fantastic rock formations. A sunstar can bring drama to an otherwise dull sky on a clear day. Consider shooting a sunstar when the sun is at the horizon, at the edge or inside of an arch, at the edge of a hoodoo, or partially blocked by a tree or cactus.

Here are some tips on shooting sunstars:

Sunstars work best when the sun is partially obstructed by a tree, rock, the horizon, ... They also work best when the sky is clear and free of high clouds or haze.
Sunstars are usually shot at f/16 or f/22 since the smaller the aperture (higher the f/stop) the larger the sunstar. Small apertures have several disadvantages however. First, lens flare is significantly higher when using a small aperture than a large one. For an example see the lenstip review of the Nikon 28mm f/1.8 here and compare the last image shot at f/16 and the image shot at f/1.8 two images above it. Second, due to diffraction images are significantly less sharp when shot at f/16 or f/22 than at lower f stops. At f/16 center resolution of most lenses is 25-30% less than resolution at the lenses best f/stop. At f/22 center resolution drops by 40-45 % from its best.
Consider shooting sunstars handheld. The sun moves fairly rapidly and must be precisely aligned in the frame when shooting a sunstar. This makes tripod positioning difficult. I usually shoot sunstars handheld when the tripod is hard to set up (e.g. a ground level shot). I shoot several images varying the position of the sun in the frame very slightly and select the image with the best sunstar and least flare in post.
Some lenses produce better sunstars than others. Primes normally work better than zooms since they have fewer glass elements. I find the prime Nikon 20mm f/1.8 lens produces much less flare than the Nikon 14-24 zoom lens with its large front element.
The number of points in the sunstar depends on the number of diaphragm blades. The number of points in the star is twice the number of blades for lenses with an odd number of blades, and equal to the number of blades for lenses with an even number of blades. For example the image above was made using a Nikon 20mm f/1.8 lens. This lens has seven blades and produces a 14 point star as can be seen above. Sunstars with a small number of points generally look artificial so lenses with an even number of blades should be avoided. Most Canon lenses have an odd number of blades, with the notable exception of the often used Canon 24-105 f/4 L which has eight blades. Nikon lenses almost always have seven or nine blades. All the lenses in the Sigma Art series have nine blades.
Live View can be useful, especially on Canon cameras. Pressing the DOF preview button in live view will stop down the lens so you can see the size of the sunstar on most Canon cameras and more recent Nikon cameras. You can also review the histogram in live view prior to shooting. For cameras without live view or where live preview is always created with the lens wide open I suggest you review the image after shooting. Review it for the size of the sunstar, flare and ghosting, and exposure.
Remove any filters. If you have a polarizer, UV, or protective filter on your lens you should remove it before shooting. This will help reduce ghosting / flare.
Use multiple exposures and blend them together to reduce flare. After shooting a sunstar move the camera very slightly to get the sun out of the frame. Shoot again. The new image should have much less flare. Combine the two images in Photoshop using Edit Auto-Align Layers and then mask in the sunstar. An image with less flare can also be made by shooting a second image with your thumb in front of the sun and masking the star from the first image in. A third alternative is to shoot an identical image to the first using a lower f/stop and then mask the sunstar from the first image in.
Use Topaz Star Effects if all else fails! Topaz Star Effects can be used to add a star to an image without one, or to replace a small star with a bigger star.

This page was last updated 11/28/2015