Today’s Question: In a recent presentation you referred to having your camera automatically capture a bracketed sequence of exposures multiple times in an interval basis. How do you set that up to happen automatically?
Tim’s Quick Answer: This technique requires configuring your camera for automatic exposure bracketing and then using either an intervalometer or a built-in feature to capture multiple bracketed exposures over a period of time.
More Detail: A bracketed set of exposures enables you to later merge those exposures into a high dynamic range (HDR) image. If you also enable interval capture, you can create multiple sets of bracketed exposures over a period of time. This could be used to create an HDR time-lapse video, for example. Or it can be used to automate the process of capturing variations on a bracketed capture, such as when sky conditions are changing.
In my case I was using this approach to automate capturing photos while I was helping other photographers setup their shots, which is what led to my very lucky capture of lightning at sunset over New York City, which you can see on my Instagram feed here (don’t forget to follow me!):
The first step is to configure exposure bracketing on your camera. Note that in many cases you may need to use a timer mode to have the camera automatically capture all exposures in the bracketed sequence rather than requiring you to press the shutter release multiple times.
The second step is to configure interval capture. I happen to use a camera that has a built-in interval capture feature, and that also allows me to use bracketed exposures in conjunction with interval capture. If your camera is not so equipped, you can use a cable release with an interval capture feature to make this possible.
For example, photographers using a Nikon camera with a DC2 connection could use this cable release for interval captures:
Photographers using a Canon camera with a 3-pin connector could use this version of the same cable release model:
So, for example, you could configure your camera to capture bracketed exposures suitable for assembling into an HDR image in post-processing. You could then make use of an interval feature to perhaps capture a bracketed exposure sequence every minute, or however often makes sense based on the rate at which conditions are changing. And if the conditions include a bit of luck, you might also end up with a photo that includes lightning, as I did with the image linked above.