So, it’s the end of winter here in the US, and the start or Fall in southern Africa. For many of us, this is not an exciting time for photography. Flowers aren’t blooming yet, it’s a little too early in the season to go on safari, so how do we pass our photo time and also work on skills that will help on safari?
For me, it’s time to look up. Yep, look up. The weather is now warm enough to be out late at night and the cool air makes for some clear skies. I’ve been taking this time to work on my skills relative to shooting the heavens. In a previous post, we’ve written about the fabulous star filled skies of Africa … and they are amazing.
Recently, one of our favorite blogs, Plan Your Safari, ran an article on the African night sky. That article and the current weather, ‘inspired me’. I have taken a few nights to work the local skies. I have been shooting both star trails as well as shorter exposure star scapes. It’s fun, and it’s actually one of the photo techniques most of us don’t often practice … and without practice you will struggle when it’s time to execute on this type shot. I know I messed up a number of times in my recent shoot.
In that prior article, I spoke of a few of the basics including manual focus on infinity, setting up your composition before the sun goes down, etc., but here is a photo tip we didn’t discuss – the impact of F-stop on the number of star trails you will capture. Here’s an example of what I am saying. Consider a star trail at f/5.6 and ISO 200. Now also consider a similar duration exposure at f/4 and ISO 800. That simple change will triple the amount of light the sensor will see. Yep, a lot more light. From f/4 to f/6 is one full stop and from ISO 200 to ISO 800 is two full stops. That means that the first exposure will capture lots of stars and trails, but the second setting will potentially be overwhelmingly busy with lots of little, faint stars leaving trails … and the African sky is full of highly visible stars. I hadn’t even thought about the impact of the really starry skies and the camera settings. So … I’ve started practicing sky shots with different ISO, apertures and different shutter speeds so I will have a good handle on these factors when summer comes and I am under the African sky.
By the way, while I would not recommend shooting animal shots at 1600 ISO (much less 3200 ISO) unless you have a REALLY good camera, skyscapes shoot pretty nicely with these settings as noise reduction software generally handles the sky detail quite well. I have printed some of my images shot on this shoot at 1600 ISO at 11″ x 17″ and they look outstanding.