On a DSLR there is a choice of settings that allow you to have different levels of control over the camera. First you need to consider what you want to do, or to be precise, what kind of result do you want to achieve?
- Av – Aperture Priority – This control lets you choose the aperture and the camera will control everything else automatically
- Tv – Shutter Priority – This control lets you choose the shutter speed and the camera will control everything else automatically.
- M – Manual – This puts you in control of everything.
Aperture priority mode is best if you are shooting an image where the aperture plays an important role. Both landscape and portrait photography put a lot of emphasis on aperture. Landscape photographers will use a very small aperture (f/22, f/16 or f/11) to get everything in focus (Deep Depth of Field). Portrait photographers use a very large aperture (f/2.8 or f/1.4) to focus on a very small area (Shallow Depth of Field). If you are shooting landscapes or portraits, you might consider using Aperture Priority and set it to an appropriate aperture. Maybe you want to use the sweet spot of your lens for general photography. Most lenses have their sweet spot (best sharpness and corner detail) around f/8.
Shutter Priority would be best suited to capturing action or fast moving subjects. If you are shooting sports, you don’t want a blurry picture so you would need a fast shutter. The light could be changing fast… in TV mode you would not have to worry about your settings, just select a fast shutter time and let the camera calculate the rest. So what is a fast shutter? 1/125 should be fine for sports on a regular lens, but as your lens gets loner, you will need a faster shutter. A 400 lens shooting birds in flight needs at least 1/1000.
This bird action shot was taken with a 400mm lens and TV mode. I set the shutter to 1600 and the camera calculated that it needed 3.5 aperture at 100 iso.
M-Manual mode is the best mode to learn about your camera. You are in complete control. If something goes wrong it is your fault. I would really recommend using manual mode for long periods of time when you get your camera. I am talking about just for practice, don’t shoot someone’s wedding in manual mode if you don’t know what you are doing!
To successfully shoot in manual mode, you need to be able to change the shutter speed and aperture yourself, so consult the camera handbook for this. You can use the light meter in the camera to adjust these settings. With an average light meter, the camera will tell you if a scene is over exposed, underexposed or just right, the beauty of manual mode is that you decide if you are going to under or over expose the shot. This decision can be the difference between a photo and a great photo.