In Focus: Maintain Stability (part 1)

Do you need a steadier hand?  Do you want to explore low light photography, slower shutter speeds or a sharpness-critical style like landscape photography?  What should you do?  Have a cup of coffee and a cigarette before shooting?  Perhaps so, but there are several other things you can do to help get sharper shots and that’s what we’ll look at over the next couple of weeks.

A shaky camera (or more to the point, a shaky hand) has been the bane of photographers since the beginning of the art.  To minimize camera shake, you need to be aware of both the shutter speed and the limitations of your ability to hold the camera steady.

A general rule of thumb is that you can safely hold a camera steady at a shutter speed equal to the focal length of the lens you are using.  So for example, if you are using a 50mm lens, you should (assuming you are trying to hold the camera as motionless as possible) be able to shoot comfortably at 1/50 sec without too much fear of introducing blur from camera shake.  Likewise with a longer 200mm lens, a faster 1/200 sec is a safe lower limit.  The situation here is somewhat analogous to holding a stick.  It’s easy to hold one end of a toothpick and keep the other end steady, but much more difficult to do the same with a broom handle.  With regards to a camera and lens, this isn’t so much due to the physical length of the lens, but the distance to the subject.  With a longer lens the subject is further away for a similar size in the viewfinder – a tiny movement of the camera here translates into a large movement at distance over there.  Keep in mind that this formula is only a rough guide for hand-held shooting and it will vary between individuals – some might need that cup of coffee or a little attention to results to see where your comfortable limit lies.

So what happens if the shutter speed goes lower?  What if we want to shoot our pals in the bar on Saturday night and the camera is telling us the shutter will be at a perilously slow 1/8 sec?  If you’re shooting film, you’re out of luck.  But if you’re taking advantage of digital’s convenience, just bump up the ISO.  The ISO value is the measure of the film or digital sensor’s sensitivity to light – the higher the number, the more sensitive to light so the camera needs a faster shutter speed for the same exposure.  Just dial it up until the shutter speed reaches a comfortable level.  Something to keep in mind when increasing ISO is that more ‘noise’ gets introduced into your image.   New DSLRs and high end point and shoot cameras have very good high ISO capabilities so it’s not a huge issue, but with older or cheaper digital cameras it is something to be wary of.

Another important thing to consider is that blurring from camera shake at shutter time is a function of probability.  That is, as you slow the shutter down, blur in the image is more likely to occur.  Using a 85mm lens at a shutter speed of 1/8000 sec, blur is vanishingly unlikely – you will get a sharp image 100% of the time.  With the same lens at say, 1/10 sec, the likelihood that you will introduce some blur is quite high.  You can however increase your chances of nailing a sharp image at slower speeds by shooting several frames, though no matter how many you shoot it is next to impossible to hold a camera steady for a 1 second exposure.

Next week we’ll look at some other ways to get a sharper image.

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