Having looked at the photos of Koi taken by proud owners, I've noticed some common mistakes:

• fish that are too small in the picture.
• blurred images.
• muddled scenes.
• distorted images (due to fish being too deep in the water).
• fish blending in with the background.
• distracting reflections and dark shadows.
• inaccurate colours.<.li>

These mistakes can all be easily avoided with a little thought and attention to detail.

This photo of Koi (Sanke, Tancho Sanke, Doitsu Kujaku, Kujaku and Kohaku) is muddled, over exposed and the leaf reflections and shadows are distracting.

Some problems relate to composition, others to camera settings. Some are difficult to resolve, such as photographing dark fish against a dark liner. The only answer here is to bowl up the fish.

If you're at the planning stage of your pond, you could keep photography in mind and consider using a blue or pale liner instead of black. However, you'll probably still have to scrub the surface before a photo session to make sure that your Koi show up well.

Apart from the problem of isolating a particular Koi in the scene, which only plenty of time can achieve, the main technical aspects are achieving the correct exposure and removing reflections on the water surface to obtain a good image with the correct colours.

Dark coloured Koi are very difficult to photograph against a dark liner. In this photograph the fish is too deep in the water and too small in the picture. At least this Shiro Utsuri has plenty of white to show it up, but this photo doesn't do justice to this prize-winning female.

The dark slate background has fooled the automatic exposure meter. The overexposed result is that the orange of this male Asagi is bleached out, and the background is smoky. With digital, or with transparency film this is the photographer's fault. Also part of the Koi's body is in shadow.