Stopping Motion

The biggest problem with train photography is that trains move, and often quite fast. It's quite disappointing to take a trip, whether near or far, go to some spot, set up and plan a nice composition, wait for the train, and then, back home, find that you have a nicely-composed and well-exposed blur. As is the case with any other moving object, if you want a sharp photo, you need to "freeze" the action. This requires a shutter speed that is short enough that it seems to stop the motion of the train.

It takes a higher shutter speed to freeze motion that is sideways than head-on. Also, the farther you are from a subject, the less its apparent motion, and the lower the shutter speed that will freeze it. Notice in the photo at the top of the page that the front of the train is blurred, but the back is sharp. For some examples, from the Kodak Professional Photoguide, a vehicle moving at 50mph requires a shutter speed of 1/2000 at 25 feet, viewed at a right angle. If it's head-on, you only need 1/500. At 50 feet, the right angle decreases to 1/500 and head-on to 1/125. There is a formula which you can use to calculate the necessary speed (it can be found in the Professional Photoguide). The formula is accurate, if you have all the right information, and the time (along with math ability or a calculator) to figure it out. It's more practical to keep the shutter speed high and, as always, to learn from your results.

People interested in train (or similar moving object) photography should consider this when purchasing equipment. A camera that includes shutter priority automation or full, metered manual exposure among the exposure options makes it much easier to keep track of this crucial factor. Cameras with aperture priority automation can do a good job if you know the shutter speed--most such cameras give you a readout of the shutter speed, but not all--but you will find yourself setting the aperture wider than you might want, just to make sure. Program automation without a shutter speed readout is asking for disaster. Some cameras provide a table showing the program's shutter-vs-aperture slope, which may give you some idea where you are, and a few offer a "high" or "action" program mode that goes for higher shutter speeds.

The practical problem with fast shutter speeds is that they require a lot of light. If you're shooting at ISO 100, your aperture at 1/1000 will be around 4.5 on a sunny day. On a lot of new cameras with zoom lenses, that's the widest available. So it's often helpful to allow your sensor to auto-adjust the speed or use ISO 400 film. Also keep in mind that in order to get the best results from slide film and digital sensors, you need a precisely on-the-spot exposure. To get the best results from print film, overexpose it a stop. All films and sensors suffer more from underexposure, but at 400 they are are particularly sensitive — they will take on strange colors and get grainy (or noisy). One could carry this idea forward and use 800 or 1600 film, as many writers advocate. If you have a zoom point-and-shoot camera, that may be true, but I find that print quality deteriorates rapidly above 400, whether film or digital. It may not always be that way — 400 used to be pretty bad, too. The same considerations apply to a digital camera, except that you can change the ISO response from frame to frame. This is pretty neat, but keep in mind that just as with film, you lose some of the sharpness to noise, the digital equivalent of grain.

It is perfectly legitimate to take a blurred photo if you want. Such photos often convey a sense of action. However, they require careful planning. One of the most popular techniques in this area is "panning." This takes a lot of practice, so don't count on doing it the first time out. The idea is to use a slower shutter speed and follow the motion of the train (usually from a moving vehicle or with the camera on a tripod). The train itself will be reasonably sharp (depending on your skill) but the background will be blurred. It conveys that feeling of motion, and is not as jarring as a sharp background with a blurred train, which rarely seems to look very good.

revised: 29 March 2010; original 23 January 2003