The Program AUTO Mode (P) on the command dial is often ignored or misunderstood, thus being less used by many photographers. Here I will give you the short and sweet of what this mode does and how to use it in your photography.
I left the Program AUTO Mode to last, as my primary goal was to get you to a point that you understood the creative modes (A or Av, S or Tv, and M) and you could start using them. These are the creative modes you will use most of the time.
How Does Program Auto Fit In?
Think of your camera modes as a continuum.
First, you have AUTO. The camera chooses the aperture, shutter speed, and ISO as well as other automated functions. The camera has full control and this is fine if you want to leave everything to the camera, although it may not produce the photo you envisioned.
Then there are the creative modes: A or Av, S or Tv, and M
Aperture (A/Av) you control the aperture while the camera chooses the Shutter Speed.
Shutter Speed (S/Tv) you control the shutter speed and the camera selects the aperture.
Manual, you have complete control of your camera. You set any combination of aperture, shutter speed and ISO.
Off Auto and in the creative modes you are also able to change many variables like White Balance, Exposure Compensation, which metering to use among many others.
The Program AUTO Mode fits somewhere between AUTO and the two creative modes Aperture and Shutter Speed.
What Can You Do in Program Auto (P) Mode?
The one thing that makes selecting Program Auto unique is that you have control over the ISO. I tend to think of this as the ISO mode. As you recall ISO adjustment is better suited for low light subjects.
This is particularly useful for shooting indoors and you don’t have or don’t want to use a flash. Switch to Program AUTO (P) and you can choose an ISO to get a proper exposure.
Shooting in Program AUTO does much more than allowing you to change the ISO. This is essentially like a supercharged AUTO mode.
With the command dial or a button, depending on your camera, you can choose a different value. These values are combinations of an aperture and shutter speed the camera thinks are good. If you don’t like the default combination given, say you wanted more depth of field, rotate the command dial until a combination fits your needs.
You also maintain control over White Balance, Exposure Compensation and more like the other creative modes.
Why Use It?
Program AUTO essentially lets the camera figure out the exposure, while also giving you the option to make changes to your ISO, settings or choose a different exposure combination the camera provided.
I must admit, I don’t use the Program AUTO as I would rather have the most control over my camera settings. It’s nice to know what it does and that you can use it as an option to leave it to the camera or change some settings.