One of the things I see new DSLR users struggle with the most is how to make use of the standard ‘manual’ modes on their cameras. You know the ones, the ones there on the dial past the Auto setting and the little picture scene modes, usually represented with varying degrees of cryptic letters. Fortunately, though the labels change from brand to brand (Canon digital SLR cameras use different labels than Nikon digital SLR cameras, for example), they function essentially the same for all makes.

So, let’s talk about these manual modes, but first, let’s talk quickly about Auto mode so we have something to compare to.

In Auto mode, your camera makes almost every decision for you. It picks the exposure it thinks is correct, sets your aperture, shutter speed, and ISO for you, and will take control of your pop-up flash, picking its exposure and deciding when to use it.

WHAT YOU CAN CONTROL: Typically in AUTO mode you retain control of focus points and color modes (vivid, natural, etc), and usually metering method. Your biggest control in AUTO mode is Exposure Compensation (EV). You use this to tell the camera how to correct for its decisions. So, if it continually overexposes, you use EV to tell it that it’s wrong, and to expose a little less.

Program (usually represented by a P) is the next step down from Auto. Program mode picks matched aperture and shutter speeds based off of its metering, but makes no other decisions for you. Program usually includes a “shift” setting, which’ll let you cycle through different equal settings to pick the one you want (Pentax cameras can shift by dropping you into either Aperture or Shutter priority, see below).

WHAT YOU CAN CONTROL: In Program you can pick your own ISO, metering method, color mode, exposure compensation, and flash. The only things controlled by the camera are shutter and aperture.

GOOD FOR: Program Mode is good for casual shooting when you aren’t worried about specific effects but want more control over flash and ISO than Auto gives you.

Aperture Priority mode (denoted by an “Av” on Canon digital SLR cameras and Pentax cameras) is where you pick the aperture and the camera decides the corresponding shutter speed based on its metering.

WHAT YOU CAN CONTROL: Aperture Priority is most importantly about you controlling aperture, but you can additionally control metering method, color mode, exposure compensation, flash, and ISO. The only thing the camera controls is shutter speed.

GOOD FOR: Aperture determines ‘depth of field,’ making Aperture Priority ideal for shooters who prefer to decide how much of a scene they want in focus.

Shutter Priority (Tv on Canon digital SLR cameras) is the counter-part to Aperture Priority. You control the shutter, it picks the right aperture.

WHAT YOU CAN CONTROL: Shutter speed, metering mode, color mode, exposure compensation, flash, ISO

GOOD FOR: Shutter speed controls motion blur, so Shutter Priority is ideal for sports or other action shooting, or for nature photographers looking to capture or freeze motion.

The original shooting mode. The camera picks nothing, you choose everything. Typically, the camera will continue to meter light which you can use as a guide while you set your exposure.

WHAT YOU CAN CONTROL: Everything, except exposure compensation. Since the camera makes no decisions there’s nothing to compensate for. If you feel an exposure should be different it is up to you to alter it through aperture, shutter speed, or ISO.

GOOD FOR: Manual is ideal for situations where you can take the time to set the exposure and where it’s important the exposure is the same through all frames. Studio work, tripod work, night photography, and photos with heavy flash usage are all ideal times to try manual mode.