Taking good photos for your TreeAlert reports
Pictures of an affected tree can be more useful than a lengthy written description of the symptoms which it displays but only if the photos are taken well and they illustrate the correct range of features.
How to take your photos:
- Make sure that the pictures are large enough to illustrate the point that you intend to show (anything less than 800 x 600 pixels will usually be too small) but are not so large that it is difficult to handle and store them (a photo of 2400 x 1800 pixels, equating to a good quality JPEG image of around 1mb in size, is a reasonable upper limit). If your camera or phone has a sensor of more than 5 megapixels and is set to capture images at maximum resolution and quality then your photos are likely to be larger than necessary. There are many software packages (some of which may already be installed on your computer) as well as free-use websites which will allow you to resize pictures easily before you upload them.
- Take your pictures in the best possible natural light, but use flash if needed, to avoid both "camera shake" (blurry pictures) and photos which are too dark to illustrate the features that you want to show.
What to photograph:
- Although it's tempting to concentrate on taking detailed images of the symptom(s) which the tree displays, its just as important to show the entire tree and its surroundings (the tree in context) and to how the symptoms are distributed on the affected parts of the tree (the symptom in context) as it is to illustrate the symptom up close (the detailed symptom). We recommend that you take several images of each type and upload only the best one in each category (a total of 3 images). Here are images of two different trees suffering from different problems which illustrate the type of image that we're looking for in each category (each photo is accompanied by a description of what can be seen by careful examination of the picture):
Tree in context
Should show the entire tree and its immediate surroundings. This provides information on the nature of the site, the conditions in which the tree is growing, whether any other plants in the vicinity are showing signs of disease or damage, and a range of other factors which may have had an impact on the health of the tree. It may also provide an overall indication of how symptoms are distributed on the crown, stem or stem base.
Symptom in context
Should illustrate how the symptom is distributed locally on the affected part(s) of the tree. This type of image helps to indicate the severity of the symptom(s) and which part(s) of the tree may be affected by a problem (e.g. browning of leaves may be the result of damage to the shoot or branch which holds them rather than direct damage to the leaves themselves by a foliar pest or pathogen). It may also help to identify the species of tree concerned if there is any uncertainty about this.
Should show the fine details of the symptom as clearly as possible. This type of image helps to indicate the small-scale distribution of dead and live tissue and any associated discolouration on the affected part of the tree or may illustrate the pest or pathogen itself. Where the symptom is variable, it can be useful to include several affected parts (such as leaves or needles) in a single picture. Placing an object in the frame to indicate the scale at which the image was taken can sometimes be useful.