Using a DSLR manually
Modern digital single lens reflex cameras have very accurate exposure and autofocus systems. However, relying solely on your camera’s auto or semi-automatic systems will not always yield the results you want. For macro, portraits, architecture, night photography and many other situations, taking control of the camera manually can be a necessity.
This article covers the basics of manually operating your camera. The first section covers exposure, the second concentrates on focus.
Manually exposing with a DSLR
Some cameras let you make an automated exposure metering even when in M mode, and this can be a good start to set your exposure. This is often achieved by pressing the AE (auto-exposure) button, or by pressing a dedicated button (like the Green button on Pentax DSLRs). Fine-tuning around that starting point will save you time.
Some older lenses have an aperture ring, located near the camera body on the barrel of the lens. The ring can be used to select the aperture value directly. Each camera operates differently with an aperture ring, so be sure to read your manual before using this for the first time.
You might find that some tweaking of your exposure setting is necessary to achieve the desired effect. Do not hesitate to take a few test pictures while setting your camera.
Once the proper exposure is decided, you do not have to change your settings again until the lighting conditions change. This can, in fact, speed up your process if you are in a controlled environment such as in a studio or under constant sunlight.
When manually setting your exposure while taking night pictures, be wary of your LCD screen. It is very easy to over- or under-expose when dark areas and bright light sources are combined in one frame.
Focusing manually with a DSLR
Focusing manually seems like a difficult process for many people. However, until the 80’s, this was the only way to focus! With a little practice, focusing manually can become almost second nature.
A bright viewfinder greatly simplifies manual focusing. Sadly, not all cameras are created equal. Some entry-level DSLRs have darker viewfinders with a smaller magnification. A lens with a smaller maximum aperture will also darken the viewfinder and make manual focus more difficult.
Manual focus film cameras had viewfinder screens designed to help the user focus manually. Some modern cameras offer the possibility to replace the stock viewfinder screen by an optional one with the same characteristics. These screens usually have a split image circle in the center. Focus is achieved when the two split images are properly aligned.
What to do when you do not have access to a split image screen (which is most of the time)? If you focus by looking through your viewfinder, the first rule is to take your time.
How to focus
Turn your focus ring slowly, while looking through the viewfinder. You will see your image sharpen as you improve focus, then it will become blurred again when you move past the focus point. Come back slowly towards the focus point, and fine-tune your focus. A few back-and-forth movements can be necessary, but after some practice the process will come naturally.
If your camera has a live view mode, this can be used to make manual focus easier. Most cameras with live view allow the user to zoom on the display, giving you an enlarged view of your scene. Using the routine described in the previous paragraph, you should get sharp images each time. Note that manually focusing with live view is often easier when using a tripod.
Some cameras allow users to trick the AF system into working with manual lenses. Called “catch-in focus”, this will only work with a manual focus lens. Simply leave the camera in AF mode, press the shutter completely, and slowly rotate the focus ring. The camera will take the picture when you reach the correct focus point. This might not work with all brands and models, however.
Keep in mind that, for most zoom lenses, you cannot assume that the focus remains constant when you zoom in or out. It will be necessary to adjust focus again each time you change the focal length.
Even though using a camera manually can be daunting at first, taking control of focus and exposure can be the only solution when all else fails. With a little practice, it will become easy and instinctive.
Sunny 16 rule
The “sunny 16” rule of thumb is based on ambient light rather than light reflected from the subject. It suggests that on a sunny day, you should set your aperture to f16 and your shutter speed to the reciprocal of your ISO value. [More info]