Andrew Benham Photography | The Long Shot

The Long Shot

March 09, 2015  •  Leave a Comment

Loyd Purvis, The Arc of Attrition35mm @ f8 for 1.8 seconds, ISO320, flash remotely triggered at full power

A few people were asking me how I got some of these type of images during the Arc of Attrition, so I thought I'd write a post about it. Its really quite a simple effect and one that I've used with good results on a couple of occasions. There are a few bits of kit that are essential and a few more that make it easier and/or better.

The basic idea is to catch a long exposure to get light trails and use the flash to illuminate the subject and freeze them in place.


You will need:

  • A DSLR - or at the least a camera capable of taking an external flash, with a rear-sync setting flash setting and bulb shutter setting
  • A flash unit 
  • A tripod

Ideally you will also have:

  • A cable release or remote
  • Remote flash triggers
  • A lightstand, monopod or second tripod

Rear sync

The way a camera works when using flash is that the shutter opens and the flash fires straight away then the shutter closes after it's allotted time. However, most high end cameras that accept an external flash have a setting called rear curtain sync (sometimes referred to as slow sync). This setting fires the flash at the end of the exposure rather than the beginning. This is essential when catching light trails, such as head torches or car lights, because we want the light trails to be laid down and the subject to be highlighted by the flash at the last minute. With standard flash the subject would be lit - and so frozen in place - with the lights continuing forward through the frame, making it look like lasers were coming out of the front of their heads!

Bulb setting

The need for a tripod is a no-brainer as this is a long exposure so we need the camera to be stable. You will need to set your camera to manual mode. Setting the camera to its bulb setting means the shutter willl stay open as long as the button is pressed. Ideally to eliminate vibrations this should be controlled by a cable or remote release. This also means you can be a few steps away from the camera which helps in both remaining relaxed and comfortable and also in directing the flash if it is not mounted on the camera - more on this in a bit.

Pre focus

In order to correctly focus the shot its essential to pre focus the camera. I do this by placing a torch in the scene where I want to focus and then focusing on the torch or it's pool of light. Once set I switch the camera to manual focus. Its best also to go for an aperture that allows a decent depth of field, somewhere around F8 is good, though you can get away with a wider aperture especially if you focus at the hyperfocal distance rather than the exact position of the subject. I won't go into too much detail about hyperfocal distance as there are plenty of good articles about it online. Basically it is the distance that guarantees the widest depth of field to infinity for a given camera, focal length and aperture.

For instance on my camera with a focal length of 17mm and an aperture of F11 the hyperfocal distance is approx 4.5 feet. If I focus at this point everything in the frame, from 2.25 feet to infinity will be sharp. So this makes it nice and easy to set up focs and gives a large room for variations in exactly where the subject will be at the point the flash fires.

I use an app on my phone to get the correct distances when focusing like this.

Get the flash off camera

If possible it makes for a better lit shot to get the flash off camera. In the above example I had the flash on a light stand which I held in position above and right of the subject. I use a remote flash trigger to fire the flash. I take a few test shots to get an idea about how powerful the flash needs to be - this should also be set to manual and will be somewhere between 1/8 and full power depending on how close you are to the subject. You might need to push the ISO up a little to ensure a decent result, if you have the chance you could get someone to pose for you and check you have the correct exposure.


So all that remains is to take the shot. Press and hold the shutter as the subject enters the frame and release it - which fires the flash just before the shutter closes - once the subject is where you want them. Et Voila!

One thing to bear in mind though is that the longer the shutter is open the more the runners will illuminate the background with their head torches, which can lead to some parts of the runners' bodies appearing transparent. So less is more when exposing the shots - aim for just enough to get a pleasing light trail but not too much that the background is over bright. Its also good if you can be off to one side as the runners will be less likely to look directly at the camera, plus the background is then also off to one side rather than in their field of view. I hope this encourages a few of you to have a go, good luck and let me know how you get on!







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