How do you take advantage of Lens stabilisation ?

Michel Gomez wrote:

Hi DP fellows, here is a question for lens experts...
I eventually found out that I can take advantage of lens stabilisation with my EF 16-35 F/4 IS USM. I can easily increase exposure time to 1/10s and still avoid movement blur. Benefit is obviously a much lower ISO.

My question is: how do I know (with this lens or any other stabilised lens) the maximum exposure time I can reach by using stabilisation ? Of course, I will eventuellu find out by trial and error, but is there a rational number-based method to use this great feature ?

Thank you very much in advance for any advice.--
Michel
https://www.flickr.com/photos/gomezmi2013/

In general I use the stated "specs" as a guide. Start with the old i/FL rule of thumb, and starting counting stops.

For example, if your lens is "rated" for 4 stops of IS, and you are shooting at 30mm (on a FF), your rule of thumb would be 1/30th. At 1/30th you should get a very high % of keepers (maybe 98%). Drop 1 stop to 1/15th (relying on IS), and you should get a reasonably high % of keepers (maybe 80-85%), drop another 1 stop to 1/8th, and your % of keepers drops as well (maybe 70%), and so on.

I find that if I am pushing things a bit, I often shoot a high speed burst of 4-6 shots, and then pick the best of those. This does two things, gets you past a potential loss of stability with the initial shutter press, and increases your chances of getting 1 shot out of several that is sharp (working on the % keeper numbers).

I have found that it is easier to push the "rated" number of stops more on a longer lens (like 100-400L ii) than an wide angle where the 1/FL starts with a slow speed anyway.

I would say that 3 stops on a 100-400L ii is relatively easy with the rated 4 stops being achievable a lot of the time. But on a 16mm, 4 stops would take you down to 1 second shutter speed, which is a lot more optimistic.

Colin