Night Photography - High-ISO test shots

[Joe Copalman]

One of the best tips I've read on night shooting was a suggestion that a shooter check his or her framing with a high-ISO test shot before committing to a long exposure.  While you may have everything lined up the way you want in your viewfinder (or even better, on your live-view screen), it's easy at night to become fixated on your subject and miss distracting elements in the background or foreground that are hidden in the shadows, but that will become quite visible after a long exposure.  

Setting your ISO to the highest possible setting on your camera, opening your aperture as wide as it will go, and - if other shooters in the immediate area are not currently shooting - using on-board flash, do a quick shot of your subject to check for any trouble spots that might make recomposing a good idea.  You can also use this test shot to check your framing, your focus, your horizon - basically to ensure that you've got the shot you want ready to go before you invest several minutes in a single exposure.  Personally, I shoot manual when I shoot at night, so for my test shots I will switch to AV, where the only adjustment I have to make is to the ISO.  Once I've gotten everything dialed in on the test exposure, I'll switch back to manual, set my ISO to 100 again, and take the shot for keeps.  

Below is a sample of a test shot and a for-keeps shot.  Both are straight out of the camera and have only been resized.  The image on the left was shot on AV mode at ISO 12,800 and f/3.5 with a burst of on-camera flash with the resulting exposure being 1/6 of a second.  The image on the right was shot on Manual mode at ISO 100, f/10, and a 115-second exposure, with a raw speedlight at full-power being popped four times from the front, and six pops of a red-gelled speedlight on the viewer's right and six pops of a blue-gelled speedlight on the left.