Hey guys, this is again Mehmood from Camlense and today I am going to answer the question, why is image stabilization measured in stops, and what is a stop when it comes to image stabilization.
When a camera manufacturer refers to how many stops of image stabilization a lens or a camera has, I always found that concept a little bit confusing like is it like the exposure stop where it’s a doubling or a halving of the amount of image stabilization or is it something else entirely.
It turns out that the stops of image stabilization refer specifically to still photography. There is a rule of thumb in stills photography that if you want to avoid motion blur and camera shake within your images, then you should shoot at a shutter speed that is equal or higher to your focal length.
For example, suppose you are shooting on a 200mm lens, then you should use a shutter speed of 1/200 or higher to avoid motion blur. Now turns out that image stabilization stops refer directly to this rule and more specifically to shutter speed stops.
Shutter Speed Stops
When you double half your shutter speed, you get double or half of the amount of light. For example, if you move from 1/50 per second to 1/100 per second, you decreased by 1-stop. Similarly, if you move from 1/50 to 1/100 of a second, you increased by 1-stop.
Relation of Shutter Speed Stops to Stabilization Stops
Shutter speed stops are directly related to image stabilization stops. Image stabilization allows you to take the same photograph so many stops slower in terms of shutter speed than you would have been able before.
If you are taking a photo at 1/25th of a second on a 25mm lens and your lens has 3 stops of image stabilization. Without the stabilization, we have to take the photo at 1/200th of a second to avoid motion blur but once we switch IS ON, we can now take the same photo at 1/ of a second, which means three shutter-speed stops slower.
An example of stabilization stops is shown in the picture above. You can see how stops work and how image stabilization is measured in stops.
Stabilization Stops in Videos
These stops are incredibly useful stuff in the photographic world, but it doesn’t really translate to video very well because we don’t typically adjust our shutter speed for exposure control in videos.
Well, it’s not that image stabilization doesn’t work on videos. I am just saying that measuring it in stops won’t be as good for videos as it is for photos.
I hope that soon these manufacturers will determine a new scale or a new set of technology that applies to the video world because arguably, we are the ones that are in the most need of solid reliable image stabilization. So, I hope that they come up with a conversion or a scale that applies to what we do.
I hope that you got your answer about the stops in image stabilization. So now you know that these stabilization stops are actually related to the shutter speed stops. That’t all for today.