Monitors show you what the view looks like through the lens.
The best monitors are those that swivel and tilt to any angle.
With a swiveling monitor, you can shoot
up at things close to the ground such as this newt.
Because an optical viewfinder is offset from the lens, what you see through the viewfinder (top) is different from the image you actually capture (bottom).
Click to explore how parallax affects your view of a subject.
Electronic viewfinders are small flat-panel displays inside the viewfinder. Courtesy of Zight.
A common monitor icon.
Click to see the light path through a SLR.
SLR viewfinders display focus areas and camera settings.
When choosing a digital camera, one of the first things to decide is whether you want one with both a monitor and viewfinder. Many of the latest small cameras have dropped viewfinders, partly to make more room for a larger monitor. This isn’t an unmixed blessing because the primary roles of these two features are quite different, although there is some overlap. If your camera has no viewfinder, you are forced to compose all of your images using the monitor. This means you have to deal with glare on sunny days and find a way to get sharp images while holding the camera out at arm’s length.
Monitors are small LCD color screens built into most cameras. Their size is specified using the diagonal measurement, in inches. Most have brightness adjustments that you can change manually, or which the camera will adjust automatically. These screens range between 1.5 and 4 inches and serve a
number of useful functions:
- Menus are displayed so you can change camera settings.
- Image composition. On many, but not all cameras, you can compose the
image on the monitor before you take it. Most digital SLR cameras don’t let you do this because they use a mirror to bounce the image formed by the lens into the viewfinder. The image sensor only creates the image when the shutter is open. One company (Olympus) has introduced cameras that use a second sensor in the viewfinder to feed an image to a tilting LCD monitor like those on many high-end fixed lens cameras. This lets you use different viewing angles for low, waist-level, and high shots. The image from this second sensor can also be used to capture movies, something other SLRs can’t do. Only time will tell if this feature catches on and spreads.
- Image review keeps an image on the screen for a few seconds after you’ve taken it so you can check it. Some cameras let you keep the image on the screen longer so you can perform some or all of the image management functions described below.
- Image management in playback mode let’s you scroll through the images you’ve taken and delete, rotate, rename, print, protect, copy or otherwise manage them. Many cameras also display thumbnails of a group of images in index view so you can quickly locate and select the images you’re looking for. Most also let you enlarge the image on the monitor to zoom in on details in your photo—a great way to check sharpness. A few cameras now have touchsensitive monitors so you can manage your images with a stylus instead of dials and buttons.
- Direct printing lets you use the monitor to select images for printing when you bypass the computer to print directly from the camera.
On cameras that let you compose the image on the monitor, the displayed image is taken directly from the image sensor, so it is a true TTL (through-the lens) view. Although you can use the monitor to compose photos, there are times when you may not want to for the following reasons.
Landscape mode shows the image horizontally.
Portrait mode shows the image vertically.
Viewfinders are ideal for following fast action as it unfolds—waiting for the decisive moment. One of the advantages of some, but not all, of them is that they don’t draw battery power so your batteries last longer. Also, most viewfinders are coupled to the zoom lens and show the same area that will be captured in the photo. There are three kinds of viewfinders and most photographers
would consider the SLR viewfinder the best.
- Optical viewfinders on digital SLR cameras show the scene through the lens (TTL) just as 35mm SLRs do. A mirror bounces light coming through the lens into a prism that directs it out of the viewfinder. When you take a picture, the mirror swings up and the shutter opens to let light hit the image sensor and create the image. These are true “what you see is what you get” viewfinders because you see exactly what the lens sees. Some cameras have interchangeable focus screens so you can adapt the camera for your preferences. For example, if you do architectural or product photography you may want grid lines in the viewfinder so it’s easier to keep things aligned. Some cameras let you add the grid lines digitally by changing a camera setting.
- Optical viewfinders on point-and-shoot cameras show the scene through a separate window that is slightly offset from the view seen by the lens. The offset view isn’t a problem except in close-up photography where parallax causes you to see a view that is slightly offset from the one the lens sees so a subject centered in the viewfinder won’t be centered in the image.
- Electronic viewfinders use a small LCD monitor built into the viewfinder to display the same through-the-lens image seen by the image sensor. Many of these cameras let you switch between the monitor and viewfinder and both show exactly the same scene and same information. Because these displays are electronic, menus can be displayed so you can change settings without lowering the camera from your eye. This is especially useful on bright days when a monitor is hard to read because of glare. It’s also advantageous for people who need reading glasses because the menu can be read without glasses if the viewfinder has a diopter adjustment control. The two biggest shortcomings of these viewfinders is their refresh rate and resolution. A slow refresh rate means that as you move the camera, the image on the screen lags behind the scene you are pointing at. When panning, the screen seems to jump between frames. On some cameras the refresh stops when you press the shutter button halfway down to lock focus so the image you capture may be different from the one you see. The low resolution of these viewfinders makes it hard to tell exactly what you are photographing. You don’t see fine details, colors, or tones the way they actually are.
In this cutaway view of a Canon SLR you can see the mirror that bounces light up into a prism for the viewfinder. The mirror swings up out of the way when you take a picture. Courtesy of Canon.