Take full control over your camera
When it comes to knowing the difference between program, auto, Tv, Av, and manual, do you feel a bit green? After this in-depth look at DSLR modes, you’ll be an expert!
Photographers, like skiers, can usually be classified into three distinct groups: Beginner, Intermediate, and Advanced. There are always exceptions, but I think many digital photographers fall into one of these categories. Similarly, most digital SLRS are equipped with several different automatic exposure modes as well as a manual mode that lets you to capture almost any kind of subjects.
Depending on where you are in your photographic development, each of these exposure modes offers specific advantages allowing you to control the creative elements within a photograph. With experience, you will learn which mode works best under any given lighting condition but if you're just getting started, lets start with the easiest ones.
Green (or Auto)
Easy being green: Many digital SLRS offer an exposure option that's commonly called "Green Mode" and is indicated by a green arrow or in this Pentax K200D is called "Auto Pict" which essentially turns your digital SLR into a point-and-shoot camera. Not all of the shutter speed and aperture choices this exposure mode are what an experienced shooter might choose but it's designed to produce sharp, well-exposed photographs.
Green is a go: The exposure of the Mission of Saint Francis de Asis mission in Taos New Mexico was 1/500th at f2/8. Not the best aperture for retaining depth-of-field but the camera's green mode did a surprisingly good job capturing this difficult late day exposure.
©2005 Joe Farace
In Program mode the camera automatically selects a suitable shutter speed and aperture depending on subject data and lens focal length. Program mode is ideal for snapshots or candid shots and anyone who wants to make images without worrying about camera technology providing instant readiness for those unexpected moments and surprises. As compared to green mode, where no exposure modification or control of any kind is permitted, most Program modes are shiftable, usually with some kind of control wheel that let's you change the shutter speed or aperture setting. This lets you control depth of field or action-freezing settings.
Tip: You can also alter exposure to satisfy your creative needs by using the camera's exposure compensation control that's usually indicated by a button with plus and minus signs and is usually adjusted in positive or negative directions by some kind of wheel or control.
Get with the program: For a long time, Program mode was my preferred mode for making available light portraits such as this one. Exposure with a Canon EOS D60 was 1/200 sec at f/3.5 and ISO 200 with a plus two-thirds stop exposure compensation because I was shooting in the shade.
© 2003 Joe Farace
While not an official mode, exposure compensation is one of the most important parts of a digital SLR. The camera's designers recognize that no amount of automation will produce a "perfect" exposure under all possible lighting situations as well as satisfy what some people might like and others might not. Since you are the final arbiter of what's "correct," Exposure Compensation lets you increase or decrease the automatic exposure by one-half or one-third stops depending on your camera and what its Custom Functions allow.
I recommend using the one-third stop option because it allows a more nuanced difference in exposure. You're going to have to read your camera's User's Guide manual to find out how your camera accomplishes exposure compensation.
Shutter Priority (Tv)
Shutter priority—aka Time Value, hence the abbreviation—mode is ideal for photographing subjects in motion, such as sports and action photography. Selecting Tv on the camera’s Mode Dial means an aperture is automatically selected to match the shutter speed chosen by the user. Unlike Program mode, make sure that the available aperture range is sufficient to provide correct exposure at the selected shutter speed. If you don’t, most SLRs will provide some kind of indication and if the selected shutter speed is too fast or too slow for an adequate exposure you’ll have to pick a different shutter speed.
Tip: Shutter priority mode gives you control over whether subject motion is sharp or blurred. When using telephoto lenses the old school rule of thumb is to use shutter speeds that are the equivalent of the reciprocal of the lens’s focal length and that’s a good place to begin. When using a 300mm lens, for example, 1/250th sec makes a good starting point.
Tv in action: This photograph of an American LeMans Series racecar was made in Shutter Priority mode with an Canon EOS 20D and Canon EF 500mm f/4L IS USM lens. I was able to hold this heavy lens steady with a shutter speed of 1/320 sec because it was supported by a Bogen-Manfrotto monopod. Aperture was f/10 and an ISO 800 was used because the image was made at dusk as can be seen by the car’s headlights.
© 2004 Joe Farace
Aperture Priority (Av)
In Aperture Priority or Aperture Value mode you set the desired aperture using the main dial and the camera automatically selects an appropriate shutter speed depending on lighting conditions. The main reason for using AV mode is to control depth-of-field that is partially controlled by the selected aperture. Depth of field is also affected by the camera’s distance to the subject and increases as the lens aperture is stopped down (larger f numbers) and decreases as the lens aperture gets larger (smaller f numbers) and the camera to subject distance decreases.
Use Av for depth control: I wanted to extract as much depth-of-field as possible, and shot this view of a colorful block of homes in Old San Juan, Puerto Rico at f/9 in Aperture Priority mode and ISO 200. Since it was a bright day, the Olympus E-3 determined the shutter speed to be 1/1000 sec so I could have probably chosen f/11 or even f/22 and still gotten another easily hand holdable speed. ©2007 Joe Farace
Tip: Depth of Field review: One of the basic laws of imaging is that only one part of a three-dimensional object can be truly in focus at the image plane and any areas in front or behind that focus plane will appear more or less in focus. At the point of critical focus, there is a range of acceptable focus that is one-third of the distance in front of that point and two-thirds behind it.
Av + IR is OK: This digital infrared image made with an EOS Digital Rebel Xti that was converted to IR capture by Lifepixel and a Tamron 11-18mm F/4.5-5.6 lens. Exposure was made in Aperture Priority mode to maximize depth-of-field at 1/80 sec at f/16 and ISO 400. © 2006 Joe Farace
There are lighting situations that can confuse even the most sophisticated automatic exposure metering system. That’s where Manual mode comes in handy. This mode is for experienced shooters and those who prefer a car with a stick shift than an automatic transmission. Manual exposure can be especially helpful with high subject contrast and strong backlight but also when a specific mood is desired. Consult your manual for the specific controls in the camera that adjust aperture and shutter speed.
Tip: Most cameras offer a Bulb mode where the shutter stays open as long as the shutter release is pressed. This allows you to make really long exposures for subjects such as holiday lights, fireworks, or special effects such as images of carnivals and amusement parks. These kinds of time exposures only be made with a sturdy tripod and you should further reduce the risk of camera shake by tripping the shutter with a cable release.
Some purists claim manual exposure mode is the only one to use but I only use manual exposure mode when working under extreme lighting conditions, such as nighttime photography or working with studio lights, to maintain maximum control over everything in the scene, which is the only reason you should ever use manual exposure:
Lights? Camera? Manual! You need to shoot in Manual mode when working with studio lights, such as this portrait of my wife, Mary, made in my makeshift basement studio using three Adorama Flashpoint II monolights. Exposure with an Olympus E-3 was 1/60 sec at f/9 and ISO 100 as was metered with a Gossen Star F-2 handheld light meter that also measures flash. ©2008 Joe Farace
What about Scene Modes?
Scene Modes are Program modes on steroids. They turn the whole job of exposure over to camera's CPU to not only make all of the relevant exposure choices—and maybe even ISO and color balance settings—but is biased toward specific shooting conditions. The Scene Mode you choose can even automatically pop-up the built-in flash!
The biggest secret about Scene Modes is that they seem to be a secret and few people seem to take advantage of them. Some cameras have a SCN setting on a control knob while others have them tucked inside the camera's menu structure but almost all point-and-shoots and entry-level digital SLRs offer some variation on the Scene Mode theme.
Nikon's icons: The mode dial on some cameras, such as the Nikon D40X, left, shows icons for various Scene modes, while others including the Pentax K200D let you select SCN (Scene Mode) and other options. In a recent survey readers where asked for their favorite Scene Mode. Some picked Aperture Priority (it's an Exposure Mode), and one said, “they are all useless.” I could not agree less with that statement.
Another one of the problems with (whatever you call) Scene Mode is that each manufacturer has decided there will be little or no standardization on what scene modes are offered are even what their names will be and so you will find similar features with different names in a camera from another manufacturer or it just may be missing.
Make a scene: After selecting SCN from the mode dial on top of the Pentax K200D, these Scene Modes show up on the rear LCD screen. When you use the camera's four-way controller, it not only selects the Scene mode but gives you some information about what each mode does.
Effect? Scene mode? What's the difference?
Don't Get Confused. Scene modes set many different parameters of the camera, including shutter speed, aperture, color balance, and even the use of flash. That's different from other controls that affect the actual look of the image. For example, recent Canon EOS digital SLRs include a set of "Picture Styles" that emulate various films' characteristics and unify the camera's settings for image processing parameters such as Tone Curve, Sharpness, or Contrast. Using Picture Styles is more or less like selecting a particular type of film in 35mm photography based on its color characteristics, contrast and sharpness.
Many lower-cost Nikon DSLRs have a Retouch menu that offers in-camera image editing features including Monochrome (black and-white, sepia, and cyanotype) and Filter Effects (skylight, warm, color balance.) Samsung and Pentax digital SLRs offer a wide range of capture options including a setting called Image Tone that offers two choices—Bright or Natural. Bright produces snappy images with more contrast and sharper focus.
Selecting Natural produces photographs that Samsung says are "finished naturally and suitable for retouching." Reading between the lines it means less contrast, slightly lighter, and softer focus. But none of these, my friends, are Scene Modes.
Is it a scene mode? Casio's EX-F1 offers a Best Shot (unfortunately abbreviated as "BS") mode that blurs the line between image manipulation modes, such as Picture Styles and Scene Modes, by combining them into one easier-to-use selection of shooting options. This photo of Mary at work shooting images from her Urban Flowers series was made in the EX-F1's Portrait mode that punched up the color and fired the flash. The camera also set the exposure at 1/640 at f/5.1 and ISO 100. ©2008 Joe Farace
Joe Farace is co-author of "Better Digital Available Light Photography" along with Pulitzer Prize winning photographer Barry Staver. It is published by Focal Press and is available in all the best bookstores, including Barnes & Noble and Amazon.com.