In this guide to your camera's Program Mode - or P Mode - we'll answer many of the common questions about what it is and how it works, as well as show you how to get more creative results by shifting the aperture and shutter speed.
Image by Marcus Hawkins
What is Program Shift mode?
Program Shift, also known as Flexible Program, is an advanced semi-automatic exposure mode - although you won't find it listed as an option on your camera's mode dial.
What you will find is the letter P, which stands for Program mode. Select this, and the camera will adjust both the aperture and the shutter speed to produce what it judges to be the best exposure for the scene or subject you're photographing.
However, you can manually override the camera's choice, 'shifting' to a different combination of aperture and shutter speed. It's by doing this that you effectively enter Program Shift mode.
So Program Shift is a bit like dialling in exposure compensation?
Not really. Exposure compensation enables you to override the camera's meter to make a picture brighter or darker, but Program Shift doesn't have any effect on the brightness of an image.
The exposure suggested by the camera remains the same: it's just that you can use a different combination of aperture and shutter speed in order to achieve it.
Why would I want to change to a different combination of aperture and shutter speed?
When it comes to exposure, Program mode always plays it safe. The camera takes the focal length of the lens into account when it meters the scene and sets the exposure, and it assumes that you're shooting handheld.
As a result, it will attempt to set a fast enough shutter speed to produce sharp pictures, free from the effects of camera shake. This means that in low light, it will choose the largest available aperture on the lens to ensure the fastest shutter speed is used.
Only when light levels are bright enough will it select a smaller aperture to increase the depth of field and make more of a picture look sharp.
While this is good news for grab shots, the combination of aperture and shutter speed set by the camera is unlikely to produce creative results.
You might want to use a slower shutter speed than suggested in order to record any movement as a blur, for instance, or to be able to choose a smaller aperture in low-light conditions when the camera's firmly fixed to a tripod.
Program Shift gives you this creative control, but combines that with the ease of use you normally associate with a point-and-shoot
It sounds a bit automated - so why wouldn't I just use my camera's Automatic mode?
Program Shift is what's known as a semi-automatic mode: you can let the camera handle the whole picture-taking process, or you can roll your sleeves up and make some adjustments manually.
For example, you can select an ISO sensitivity, tweak the white balance and picture style, and dial in exposure compensation. Your camera's Automatic mode - the green icon on the mode dial - doesn't give you this level of freedom.
You may be able to choose a drive setting and decide whether to fire the flash or not, but that's about your lot.
SEE MORE: White balance explained: how cameras correct the colour of different types of lighting
How do Aperture Priority or Shutter Priority differ from Program Shift?
In both of those modes, you select one aspect of the exposure - the aperture (in Aperture Priority) or the shutter speed (in Shutter Priority) - and the camera automatically matches this with an appropriate shutter speed or aperture.
When you're working in a hurry, it can be easy to just focus on the part that you're manually selecting and neglect to check the setting that the camera has chosen.
Sometimes this can lead to disappointing results. Take Aperture Priority: as you change the aperture, the shutter speed may drop too low to give sharp handheld pictures.
Program Shift can be a better option for grab shots where there's little time to think. You can press the shutter release and be confident that the camera will always opt for a shutter speed that will give you sharp results.
Are there any drawbacks of using Program Shift?
If you know you want a particular effect, such as a shallow depth of field or a slow shutter speed, it can often be quicker to work in the appropriate mode mentioned above.
Having to scroll through a range of combinations in Program Shift until you come to the one that best matches the effect you're looking for takes a little longer.
On some cameras, any 'shifted' exposure combination in Program Shift will only be available while the camera's meter is active.
If you take your finger off the shutter release and the aperture and shutter speed disappear from the viewfinder or the LCD screen, the shifted exposure will be lost.
When you dab the shutter release to activate the meter again you'll be back in Program mode, with the initial combination of aperture and shutter speed that's been suggested by the camera.
