Each Digital Camara provides today several modes to the user, there are modes that are specific for certain situations like landscape mode, portrait mode, night picture etc.Those modes are usually presets that work fine for those particular situations but it doesn't mean that your landscape picture will be perfect because you put your camera in landscape mode and pressed the shutter. All those modes are completely beyond the user control so we don't have a lot to say about them, you just set the mode and press the shutter without much control of what happens. This is why we are not covering those preset modes in this article.
We are going to talk about the five modes that are usually present in any good digital camera either point and shoot or DSLR: Full Auto, Program, Aperture Priority, Shutter Speed Priority and Manual Mode. Nikon and Canon models will be commented but the information works in the same way for any camera that has the modes that we present.
Full Auto Mode
(Auto in Nikon Models, green Rectangle in Canon)
In Full Auto Mode the camera takes all the decisions for the user, it automatically selects the aperture, shutter speed, flash use and ISO setting depending on the level of light and the picture to be taken. While this mode is usually good for point and shoot situations it is not really very recomendable because there is no camera in the market yet that can take decisions as good as a human being.
Program Mode
(P in both Nikon and Canon models)
Program mode is very similar to Full Auto, the camera automatically selects the Aperture and Shutter speed to match the current conditions, the diference is that it lets the user adjust several settings like ISO speed, exposure compensation, use of the flash and others in case the selected values are not right for the scene. Some cameras also allow the user to creatively alternate different combinations of aperture and shutter speed that will render the same exposure results according to the camera sensor. This mode is the one you want to leave preset in your camera when you store it because you can just turn the camera on and press the shutter button in case of a "moment" picture. The only difference with full auto is the freedom to change some parameters if what the camera suggests is not enough.
Aperture Priority Mode
(A in Nikon Models Av in Canon Models)
In Aperture Priority Mode the user selects the aperture that she or he wants and the camera automatically selects an appropiate shutter speed to match the selected aperture for a right exposure. This mode is useful when you are sure about the camera meter being right about the exposure and when you are sure about which aperture to use. In normal lighting situations with general pictures selecting f8 and letting the camera select the shutter speed can work as an enhanced Program mode because you are controlling the aperture.
Since the aperture controls the depth of field aperture mode is very important when you want to creatively control the depth of field of your picture, you probably want a narrow aperture (f22 for example) in landscape pictures to have a broad depth of field and you probably want a wide aperture such as f2.8 for portraits to blurr the background. Whenever you are sure about the aperture to use and you can trust the camera meter to decide the shutter speed that matches you can use this mode.
Shutter Speed Priority Mode
(S in Nikon Models Tv in Canon Models)
In this mode the user selects the shutter speed and the camera decides the aperture to use to get the correct exposure level in the picture. This mode is not used as often as aperture priority but is still important in some specific situations.
Setting the shutter speed allows the photographer to control the sense of motion in the picture, in sport events or when you need to "freeze" a situation a very fast shutter speed might be needed to capture the subject without blurring. You might also want to select a slightly longer shutter speed for panning when taking pictures of moving objects to get the object in focus with a blurred background for a sense of motion.
Since manual mode is probably the de-facto mode for creative uses of shutter speed the shutter speed priority mode is usually common when you need to take a picture of fast moving subjects and you want to freeze them in your picture, you can then select a shutter speed such as 1/500 and let the camera decide the aperture to use.
Manual Mode
(M in both Canon and Nikon models)
In Manual Mode the user has complete control of both Aperture and Shutter Speed as well as all the other settings in the camera. This is the default mode when you have time to take your picture and you know what you want from your scene. In order to use manual mode you usually select the aperture you want to use according to your depth of field and then take a metering in some relevant place of your picture to adjust the shutter speed to the right exposure you want then the picture is recomposed and the picture is taken. Small variations of the shutter speed can be used to change the exposure level keeping the aperture at the value that you need.
In other words Manual mode is normally used in a very similar to aperture priority mode with the difference of not relying in the camera meter to decide the exposure for the whole picture. The photographer decides depending on the lighting conditions where to meter and then adjusts the shutter speed accordingly, when the picture is recomposed the camera usually yells that the exposure is wrong but that shouldn't be the case in the final picture if the phographer judgement was fine.
Conclusions
- Do not use Full-Auto mode, leave that for people that don't read this kind of articles.
- Have your camera ready in Program Mode in case you need a picture taken in milliseconds, even pros do this.
- Use aperture priority when lighting is even and you want to select the aperture to control your depth of field.
- Use shutter priority mode when you need to freeze a fast moving subject or when you want to imply motion and you don't have enough time for manual mode.
- Use manual mode for pictures where you have time to select all the perfect settings for your picture.
