Getting a decent trophy shot at night can be tricky, but where you are not allowed to retain fish or prefer not to do so it is a necessity. It is possible to vastly improve results whatever the camera that you use. Whatever you do don’t use ‘Night Mode’ if you have one on your camera. This will slow the shutter speed right down and mean that blurred pictures are very likely. Auto will usually work well after dark with flash enabled.
During the day, you want as much light as possible and so an open spot is usually best, but at night it is advantageous to find cover. This will help to bounce more of the flash and illuminate the scene better. Find a hedgerow or some sort of solid background, and get the mat as close to it as possible. Without a background, the shot will appear very dark and the fish will often be over exposed.
A separate flash unit really does make a big difference to night photography. Because most on-camera flashes are located directly above the lens of the camera and the wet flank of the fish reflects light, if you take a shot from side on, there will often be a large patch of light where detail is lost on the side of the fish. There are several ways to help reduce this. The easiest way is to simply angle the fish very slightly, rather than have it side on. This will bounce the flash off at an angle and reduce the problem. Alternatively, moving the camera further away from the fish and zooming in using the lens will reduce the intensity of the light hitting the fish. You can also ‘diffuse’ the flash by the old trick of sticking a cigarette paper over it. Again, this reduces the intensity of the light hitting the fish and will improve results.
The best results when taking trophy shots at night can be achieved by using multiple flashguns positioned around the scene. Not only can you avoid ‘bounced light’ but it is possible to make the scene look almost like daylight, and colours are much enhanced.