Thanks — glad it helped. For variable zoom lenses, I just usually estimate how far I’ve zoomed in or I glance at the lens barrel to see where it is. So if you were using the 1-by-the-focal-length rule, if you were zoomed all the way out on a 70-300mm, you could use 1/70th as a safe speed, and if you’re zoomed all the way in, then use 1/300. The reason I mention doubling the focal length (meaning use 1/140th for a 70mm lens) is because on most digital camera (all except full-frame cameras), the focal length of the lens is multiplied by a certain amount. On Canon cameras, a lens that says it is 100mm, is “effectively” a 160mm lens, so 1/200th is a better “safe speed” than 1/100. The old rule was created for film cameras that do not multiply the lens’ focal length…

Thanks again,
Paul

Great article. I was making a few frustrating mistakes when it came to shutter speed and this is going to help me a lot. I like the rule of thumb of 1 by the focal length but when it comes to that my question for you is – what is the optimum shutter speed to select when using a variable zoom lens like a 70-300mm for instance.

Thanks
Shaunak

Best,
Paul