Records can be made of evidence from visual examination in various ways. A written description is a quick method of recording key details. Written descriptions of evidence should be as short as possible to give an accurate and clear record.
Written descriptions have the advantage that they can concentrate on the most important visual information. They can also record details of movement and change over time, which is not possible in a sketch or still photo. Notes might include the flight pattern of a bird, or the changing colour of a test strip.
Drawings can be used to record visual information. The type of drawing can vary from a quick sketch used as a memory aid to a detailed, accurate, measured drawing as a permanent record. Both can be useful.
Photographs and videos
photography, whether still or video, can be a quick and accurate way to record. It can be used for all sorts of visual information, from close up or telephoto shots to remote 24-hour surveillance. The level of detail recorded varies with the quality of the camera. Image- enhancement techniques can sometimes be used to gather extra details from poor quality photos.
modern fingerprints analysis uses automatic recognition sofeware to compare prints with those on a database. A fingerprint expert then carefully compares the likely matches to make a final identification. In photographs of faces, key facial features can be measured to confirm a match.
Sometimes evidence of certain key features is all that is needed. For example an environmental officer needs to know whether a certain sort of mayfly nymph is present in a sample. The key feature to look for is the three hairy tails. There is no need to record details of every creature found.