Outdoor Photography. Chiz Dakin

the image – and memory cards are cheap these days. If there’s even a slim chance of wanting to make a large print or publish the image then use Fine, or whatever your camera maker calls the best setting. At the other settings some data is thrown away and there’s no way to get it back, whereas a Fine image can always be compressed later if you want to email it to someone.

      Hampsfell, Cumbria, looking towards the Coniston Fells (Jon) When you’re shooting in the red light of sunset you may not want the camera to ‘correct’ the white balance

      Campfire in Wadi Rum, Jordan (Jon) Noise is random variation in brightness and colour

      There may also be a choice of size settings. Large means the maximum image size possible from that sensor – 12 megapixels or whatever it is. Smaller sizes shrink the whole image to the equivalent of, say, six or three megapixels (this is not the same as trimming or cropping it). Again this is an advantage for email and web use but is essentially irreversible. You can’t resize a three-megapixel image back up to 12mp if you decide you do want to make an A3 print after all. Well, you can, but it will look terrible.

      White balance

      The colour of light – natural and artificial – varies widely. Most of the time our eyes adapt and we barely notice it. By default, almost any digital camera will be set to regulate the white balance automatically and this will probably give natural-looking colours under most conditions. However you may want to take control yourself. Perhaps you generally like a warmer or cooler result than the camera delivers, or perhaps there are specific circumstances where it doesn’t quite get it right. When you’re shooting in the red light of sunset you may not want the camera to ‘correct’ these colours (see Chapter 3).

      ISO and noise

      The concept of ISO sensitivity was introduced in Chapter 1 (Sensitivity). Many cameras can regulate it automatically but, as suggested already, this is one of the most important settings of all, so it really pays to understand what it means and at least consider taking direct control.

      Ridge above Matho Valley, Ladakh (Chiz) Manual mode is a good choice for controlling tricky exposures

      The ISO setting doesn’t just affect the interplay between aperture and shutter speed. It also has a direct impact on the quality of the final image. Increasing the ISO tends to reduce the dynamic range and the intensity of colours, but what’s usually most noticeable is an increase in image noise. Noise is random variation in brightness and colour which produces a kind of speckly interference in images. Most cameras have various noise reduction features, and you can also address it when processing images on the computer, but strong noise reduction can make the image softer overall. The range of ISO settings which is genuinely usable depends on your tolerance of noise and how you view the images (large screens or large prints show up faults more readily). Small-sensor cameras suffer much more from noise, so the usable ISO range runs out more quickly. The top limit for decent-size prints from a compact is probably 800 or even 400 ISO, whereas a full-frame SLR will still be delivering acceptable results at 3200 or higher.

      Many noise reduction programs (see Chapter 12) allow you to change the colour part of the noise independently from the ‘grain’ (or luminosity) part – this is useful where you don’t want to over-soften a very noisy image – as often it is the colour part of noise that is least appealing.

      Other settings

      When shooting JPEG, various other image settings are also up for grabs. These can include sharpening, saturation and several other parameters. These are usually rolled up together under some broad heading such as Picture Controls (Nikon), Picture Styles (Canon) or Creative Styles (Sony), but on some cameras you can drill down into these to alter the parameters individually.

      Another clutch of controls aim to tackle problems caused by high dynamic range (excessive contrast). These have names like Active D-Lighting (Nikon), Auto Lighting Optimizer (Canon) or Dynamic Range Optimizer (Sony). Again these are usually rectified automatically by default but many cameras will allow you to intervene if you want more control over the way the final image looks. If you really want ultimate control, don’t forget the option to shoot RAW.

      Camera Controls

      Exposure modes

      Some exposure modes basically just decide how the camera sets aperture and shutter speed, and perhaps whether or not the flash will operate, leaving you to control other parameters. On digital cameras other modes may hand most or all of the decisions to the camera.

      The first group are the traditional modes: Program, Aperture-priority, Shutter-priority and Manual. In Program mode the camera determines both aperture and shutter speed, according to some preset rules. In Shutter-priority you set the shutter speed and the camera then determines aperture to give a correct exposure. In Aperture-priority mode, you set the aperture and the camera then determines shutter speed to give a correct exposure. In Manual mode, the most traditional of all, you set both aperture and shutter speed. All exposure modes regulate aperture and shutter speed. The point about these four modes is they do nothing else: other settings like ISO and White Balance can be changed independently.

      Most makers use P, S, A and M symbols to denote these modes. However, for some reason, Canon uses Tv instead of S. It’s supposed to stand for Time Value, which almost makes sense, but now that many cameras can be connected directly to a TV set to play back pictures, this is bound to cause confusion.

      Farleton Fell, Cumbria (Jon) Landscape mode will favour good depth of field and process the image to give vibrant colour

      Most cameras also have a range of other exposure modes. Terminology varies: for convenience we’ll call them Scene modes.

      These normally pre-determine most camera settings. For example, when you choose Landscape mode, the camera determines aperture and shutter speed in a particular way, but it goes much further. It will probably turn the flash off, for a start, and you may be blocked from activating it manually. Most people rarely use flash when shooting landscapes, but there can be occasions when you do want it to lighten up a dark foreground. Other modes might do the opposite and automatically activate the flash, leaving no easy way to turn it off if you don’t want it.

      Scene Modes also affect the way the image is processed. For example, Landscape mode usually delivers quite punchy, saturated colours while Portrait mode aims for a softer, more ‘natural’ (and hopefully more flattering) result. Experimenting with Scene modes can produce remarkably different results – and is a great first step to discovering just how flexible even a simple camera can be.

      Focusing

      Most cameras focus automatically. SLRs and other system cameras generally also give you the option of focusing manually. But the reality of autofocus (AF) isn’t quite as simple as it may seem.

      Depth of field, which we’ve already considered, muddies the water for a start. A lens can only focus at one distance at any one time, but depth of field will sometimes make objects appear sharp even though they are nearer or farther than that distance. So, even if the camera hasn’t actually focused exactly where you intended, depth of field sometimes makes up for it.

      Chris Radcliffe’s hand, Burbage Rocks, Peak District (Chiz) Even ‘people’ pictures don’t always benefit from Face Recognition technology!

      But that hints at the next question. How does the camera know where you