In previous posts about ISO, Aperture, and Shutter Speed, I explained how these values are measured in what are called stops. I created this chart so you can easily see what one full stop to the next is in ISO, shutter speed, and aperture.
I created this because I do a lot of what’s called HDR bracketing. I’ll do a more in depth post on HDR at a later date. The basic idea is that camera sensors are very limited in the range of detail from the brightest highlight to the darkest shadow that they can capture. It’s typically no more than about 1 to 2 stops max. If you want to capture the full range possible in a scene (or even beyond), and your subject isn’t moving, then do a bracketed exposure. This is when you take multiple pictures at different exposure levels and combine them in the computer. So for example: let’s say you are photographing a landscape and the correct exposure is 1/125th of a second at f8.0, and 100 ISO. A 2 stop bracket would have you taking one picture at 2 stops underexposed (1/500th at f8.0 and 100 ISO), one at the correct exposure, and one 2 stops overexposed (1/30th at f8.0 and 100 ISO). Then you can combine the 3 images in Photoshop or some other HDR merging program, and have a final image with 5 stops of dynamic range instead of 2. I will often do images with 12 stops. I only change the shutter speed so my ISO and aperture remain the same. The problem is that my camera has limitations on how high the shutter speed will go. My fastest shutter speed is 1/8000th of a second. Most cameras are limited to 1/4000th. So if I want to do an exposure that is 6 stops under exposed then the fastest my starting out shutter speed could be is 1/125th of a second. So I would adjust my ISO and aperture until my starting shutter speed was 1/125th of a second and shoot my bracket. To do this right you will need a tripod and cable release as you will get into some seriously slow shutter speeds. This chart helps me quickly see what my shutter speed will be at the extreme ends of my bracket.
I added the values for ISO and aperture as well so you can see the order of whole stops. Note, if it’s in yellow then it’s outside the range of current camera technology. I just put them in for illustration.