Lessons from the Shot: Camera Modes Demystified By George Hsia

 By George Hsia, www.georgehsia.com 

 Figure 1
Av-M-P-B-Tv does NOT mean the “Average Man Parked Before a Television”. Although it may be true in some homes, in photography, it has a totally different meaning. Do those unexplained camera dial modes come to mind?
On many digital cameras, those cryptic letters have significant meanings regarding how the shutter and aperture work together. The following is a translation of the cryptic.
Auto – Auto everything
Auto is good if you don’t want to think about the settings. However, the camera often gets confused, so it is not uncommon to shoot an incorrect exposure.
P – Automatic aperture and shutter speed. 
P acts like full auto, with the ability to adjust for the camera’s metering. It’s nice when you don’t want to worry about aperture and shutter speed but want to have some control over ISO for (indoor/outdoor) and exposure compensation when the camera meter’s too dark or too light.
M – Manual everything
Full manual is great when you want full control over all of your settings. Once you have exposure dialed in, you’ll always get the right exposure. Manual is difficult in mixed lighting environments where the ambient light changes frequently.
Av/A – Aperture Priority (Aperture Value)
When using Aperture Priority, the photographer sets the aperture, while the camera automatically adjusts the shutter speed. It is useful to lock in the aperture and control the depth of field. It’s also very useful for shooting mixed lighting situations, where the light varies frequently. The Av Mode allows the shutter speed to adjust automatically based on metering, exposure compensation, aperture and ISO.
Tv/S – Shutter Priority (Time Value)
The photographer adjusts the Shutter manually. The camera adjusts the Aperture (f-stop) automatically. Shutter priority is useful when you want to lock in the shutter speed, i.e. during sports or long exposures where you need a specific shutter speed.
These modes are designed to help or hinder the photographer. We hope it helps more than it hinders.