Image Sharpness: Shutter Speed, Handholding and Stabilization

This is an informative read. The takeaway is that making sharp hand-held photos requires faster shutter speeds than you might expect. The author suggests halving the exposure that’s suggested by the old reciprocal-of-focal-length rule of thumb: for example, use 1/100th of a second rather than 1/50th with a 50mm lens. I think this is optimistic, or to frame it differently, you will get an increasing percentage of sharp hand-held images as you continue to decrease your shutter speed to well below 50% of the reciprocal of your focal length. With a 50mm lens, for example, 1/100th second is better than 1/50th, but you are even more likely to get a sharp image at 1/250th, 1/500th or even faster. YMMV as they say on the Internet, and there is no substitute for experimentation to find what works best for you. In my case I often don’t get images that are routinely sharp at 100% magnification unless I use shutter speeds approaching 1/1000th of a second or faster. This means that I tend to get better results in bright sunlight at ISO 400 than 100, a result that surprised me when I first noticed it.

Related points to keep in mind:

-In fading light, any camera/lens combination will have an exposure length beyond which you will start to get too many blurry photos. With a modern DSLR it’s usually best to err in favor of increasing ISO sooner than you need to.

-There is no substitute for a tripod.

-Turn off image stabilization when you use a tripod, unless you determine by testing that stabilization helps. (Here’s a helpful discussion of issues related to stabilization.)

-It doesn’t take much wind or vibration (e.g., if you are standing on a heavily trafficked bridge) to degrade the sharpness of photos made on a tripod, particularly if you are using a lens of longer than normal focal length. Such image degradation is most easily detected by comparing 100% views of sequential photos made as part of a series to be stitched together, as for a skyline panoramic. Even subtle blurriness stands out.

-Some tripods are better damped than others. Use your camera’s live view feature, set on maximum magnification with a longish lens, to get a feel for how quickly your tripod settles down after you touch it or change camera positions. You may find that a conventional 1- or 2-second mirror lockup delay is inadequate and that you get sharper results by using a remote shutter release or even the full-length delay of your camera’s self-timer. This is also a good way to determine if it’s too windy to make sharp images with any technique.

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