Basic Photo Theory and Digital Workflow (3 of 4)

Now that we have decided whether to shoot in Raw or Jpeg/Tiff mode (preferrably RAW), and understand how correct exposure is achieved, albeit usually automatically in the modern Digital SLR, and that whatever aperture we choose, or is chosen by the camera's program, affects the Depth of Field around our subject (focal point), we can now look at the steps to consider, and thought process, when taking a photograph.

General Setup & Composition

Most 'casual' photographers will carry their camera around with them, not fully knowing what photographic scenes they will encounter on a daily basis, and generally shoot as they find their subject matter. This can range from close-ups to landscapes, with everything in between, not to mention the ever changing weather and thus lighting conditions.

Most of us will therefore have a general 'walkabout' lens attached, usually these days a medium focal length zoom lens, which is ideal for this type of use. Although a 'normal' prime lens (50mm +/- 20mm) is equally fine. My preferred camera default settings would be 100 ISO (or 200 depending on your camera's lowest setting), in Aperture Priority (A) exposure mode, with Matrix Auto Focus mode. Exposure Metering would also be normally configured for matrix or center weighted metering, but you should be aware of spot metering required for precise area readings or close-up work.

I would also have my lens aperture set at f5.6 - f8 or thereabouts, which is a good mid aperture point to have set when you raise your camera to your eye when first considering a shot. F8 or a mid-aperture setting on a lens also happens to be what is known as the sweet spot, ie the range where least optical aberrations occur, and therefore produce best quality and sharpest images.

Aperture can then be adjusted depending on what the lighting conditions are, or how much depth of field you want around your subject, remembering of course that any aperture adjustments will accordingly affect the shutter speed as your camera's software tries to maintain a perfect exposure. Also remember that for any given aperture, the distance you are from the subject also affects the depth of field.

Also, as mentioned earlier, if you are shooting in Aperture Priority mode, be sure to check that the aperture you have selected hasn't selected too low a shutter speed, which might cause camera shake... particulary in changing lighting conditions. Compromises always have to be made, either by selecting a wider aperture, increase in ISO setting, or indeed use of tripod. Light is an ever changing dynamic thing, so be prepared to adapt.

More organised photographers may set off with a firm photoshoot in mind, and will have selected one or more lenses to carry, along with any other accessories they may need, such as flash or tripod. Even so, they'll still usually have a general purpose lens fitted in 'ready to go' mode (as above), just in case they stumble upon an unexpected opportunity. No matter how organised you are about your hobby, it is often these opportune shots that are the real winners, and the most memorable, so it is best to have your camera ready at all times.


Good composition is quite literally in the eye of the beholder, although artists down the years have found that certain positioning of the main subject, or key elements, within a composition can have a more pleasing effect on the viewer. There will always be rules to any aspect of art, and as always, rules can be broken, and indeed with certain subjects, compositions that fly in the face of common sense can add tension and abstractness to an image. However, some simple rules of composition DO work, and although images can be cropped and re-jigged further down the workflow process in your graphics program, it is useful to bear them in mind when initially considering and lining up your shot.

There are a few don'ts in composing a shot. It is quite normal when first viewing your subject through your viewfinder to place it in the centre of the screen, but as a finished image, a centrally placed subject can look quite uninteresting. It can work for some subjects such as portraits and blooms, but even they can look more pleasing if offset slightly.

Similarly, shots like landscapes can look quite boring if the main horizon (or a strong vertical) is placed across the middle of your image. Again, offsetting this line away from the center can add interest, and encourage the eye to wander around the image, instead of sitting centered on the middle of the composition. The amount you offset horizontals, verticals, and main subjects from the center is fairly critical also, as small offsets look unintended, and too large can place key elements too close to the edge of your image.

Rule of Thirds

Probably the most popular compositional rule to consider is the 'Rule of Thirds'. This is a technique of setting up your shot so that the main subject or key element is placed within your composition along imaginary lines, dividing your image into thirds, vertically and/or horizontally.


As you can see from the above examples, placement on the imaginary rule of thirds grid doesn't have to be exact, but as a rough rule of thumb works very well. Placement of any element in your image at an intersection point (circled) will give it added importance within the composition and unconciously draw the eye to it.

Although images can be cropped later with your graphics software to optimise your composition, the rule of thirds is an easy aide memoire to keep in mind when you're taking your shots. A slight change of position, or change in focal length with your zoom lens can help with the original composing of your image.

Remember, most digital SLR cameras have a focus lock when you half depress the shutter release button. So bearing in mind you want to offset your subject to position it on the imaginary grid, you would first view your main subject centered in the viewfinder, and half depress the shutter release to attain auto focus. Then, with the shutter release still half depressed, slightly move your camera to re-position the subject to the offset you want in the viewfinder. Then, when happy with the composition, fully depress the shutter release to take the shot. It takes a while to get used to this method, but after a while becomes second nature.

Theory & Workflow continued (4 of 4)...