focal length vs shutter speed

[Aunt Flo]

Hello everyone
just a quickie from me.

If I'm using a 18mm-200mm lens on my camera hand held, the shutter speed must be set at above 200 (err 250?) to avoid shake.

Even if I haven't zoomed in? ie 18mm

I guess this would be especially important is there was movement in the photo.

Thank you!

 

[Nod]

No, Flo.

It's the focal length you're using that determines the sutter speed at which you can handhold the camera, and the crop factor needs to be taken ito account as well (1.5x in the case of Nikon Dx bodies). So, at 18mm, the preferred shutter speed would be 1/18x1.5, so 1/27th - nearest speed on most dials would be 1/30th", at 70mm, 1/105th", 100mm, 1/150th" etc. The 1/focal length rule is a very loose rule of thumb - to be sure what you can hand hold, do some experiments. Rest for a couple of minutes to let your heart rate settle, then shoot at a few speeds around the speed the rule of thumb suggests and see what YOU can handhold with your kit. May be worth doing with all your lenses - any that have VR/OS/etc will allow a few extra stops and a lighter lens may be easier to hold steady than a heavy one.

If you're shooting a moving subject, you'll still need a speed fast enough to freeze subject movement, unless you're panning (which is a whole new ball game!). There are lists of what speed you'll probably need to freeze normal walking, jogging, sprinting, cycling etc but I don't have any links to them. Some kind soul may post one or two such lists later!

 

[hollis_f]

The 1/focal length rule is a very loose rule of thumb - to be sure what you can hand hold, do some experiments. Rest for a couple of minutes to let your heart rate settle, then shoot at a few speeds around the speed the rule of thumb suggests and see what YOU can handhold with your kit.

This is so much better than following a dumb rule that really doesn't work for most people. I can, most of the time, shoot at around 2/fl to 4/fl, whereas my friend needs to shoot at 1/4xfl to be sure of eliminating camera shake. That's around a 16-fold difference.

 

[Nod]

As I said in another thread, in my yoof, I could handhold a 50mm (on 35mm film) down to 1/30th", now I would be happier at 1/60th! I don't have a list of lenses and focal lengths with the handholdable speeds on it but these days, we (mostly) have the luxury of instant image review and can reshoot immediately if camera shake has crept into our shots.

When Dad was a young man, he could shoot even slower speeds but in later life developed a "benign essential tremor" (although, as he put it "what the f*** is so benign about a condition that makes you shake like this?") which made much under 1/250th on almost any length questionable.

 

[modchild]

There are a lot of variables that determine the shutter speed your able to shoot with. The weather will have an influance on the shot, if it's really windy it will introduce shake, as will low temperature. Movement in the subject is another factor, so as others have said, the best way is to practice and see what you are comfortable with.

I managed to get a shot of a waterfall earlier this year, shot with a 5D MkIII and a Sigma 150-500 OS, handheld in decent weather and I got the shutter speed down to 1/10sec. Conversely, at other times with the same set up I can't get a decent shot at 1/250sec, specially if it's windy.

 

[Summerstar]

Handholding at slow shutter speeds is all a matter of technique.

Using a full-frame camera, the rule of thumb used to be that the slowest shutter speed you should use is the reciprocal of the focal length you're shooting at, or higher if it's an intermediate. So, shooting with a 200mm lens, you would use a minimum shutter speed of 1/200th - in practice, 1/250th. If you're using a zoom, then the focal length is what you're actually shooting at, not the maximum focal length of the lens.

But that's exactly what it says - a rule of thumb. Good technique will let you get good results a couple of clicks below that. Get your stance right, with your feet about as wide apart as your shoulders and with one foot in front of the other. Tuck your elbows into the side of your body. Use one hand on the camera body and the other cradling the lens. Then, remember you're shooting, and the technique is the same as when shooting a rifle. Any former soldier can tell you how that's done - take three deep breaths, breathing in slowly and out in the same fashion. This oxygenates your blood and slows your heartrate and pulse momentarily. When you empty your lungs after the last breath there is a brief moment before your body starts agitating to breathe in again - a few seconds. For this brief period your body is as still and quiet as it can be without being dead - and it's when you gently press the shutter.

I've successfully shot with a 300mm lens at 1/60th like this; obviously it doesn't work every time, and as someone already said, wind and cold will work against you, but shooting from the shelter of a wall or such, and dressing warmly helps negate these. And taking several shots means that the chances of at least some being sharp are quite high.

A further thought; if you're using a cropped sensor camera then you have to take the crop factor into account; A Nikon DX camera has a crop factor of 1.5, so that 200mm lens is effectively a 300mm; I believe that Canons have a slightly different factor but the same principle applies.