Display

Display

Introduction

In reflex digital cameras,as in compact ones, the display is become more important every day. The principle characteristics of a display are its resolution, dimensions, ability to see the screen in bright conditions, viewing angle, ability to orientate the display, anti-scratch treatment and various functions, such as the LiveView function.

If the display is good, it allows us to see details in the photos taken so we can see if the exposure is correct, if the images are in focus and if they are framed well. With a high quality display, one that is crisp and large, we can also decide which photos to discard without having to use a computer. We can also use the display to frame our photos using live view instead of the optical viewfinder.

The resolution and dimensions of the display

As with all screens, the digital camera’s display has its own resolution. This is the most important characteristic of the display because it allows us to see high quality images. The display’s resolution is measured in ppi (pixels per inch). The greater the ppi, the greater the display’s resolution will be. Manufacturers almost never give this value in their technical specifications. It is not very easy to calculate with the data furnished by manufacturers. Therefore, the quickest method is to compare the total number of pixels. The high the number of total pixels, the better the display’s resolution will be (as long as the dimensions of the display are the same). A greater resolution will allow us to see when photos are blurry. Obviously, if the display is large, it is surely better, but not to the detriment of the resolution.

Live View

An important function of the display, in cameras that have this functionality, is the live view. The live view allows us to use the display as if it were an optical viewfinder and allows us to frame the photograph using the display instead of the viewfinder. During the use of live view (see figure 01), the mirror of the reflex camera has to remain in the shooting position, in other words raised, so that light can hit the sensor instead of involving the viewfinder. When live view is in use, the viewfinder will remain obscured because it does not receive any light.

01 Live view: mirror in the shooting position.

Sensor

Processor

Signal amplifier

Display

Advantages of live view

One of the advantages of live view is the fact that the image produced on the display is created by the sensor from the light entering the lens. Therefore, the image on the display is exactly what the sensor sees. For this reason, it has 100 percent coverage whereas the optical viewfinder, at times, does not have this coverage. Another advantage of live view is that it can comfortably frame an image when using the viewfinder becomes uncomfortable, such as when the camera is too high or in a position where we have to raise or lower the camera with our hands or are using a tripod.

In many digital cameras, then, the live view makes some functions accessible that are not present with the optical viewfinder. An example is the changing of the autofocus pointer on any part of the display in order to focus on any image zone; in this mode one is able to adjust the camera even if is anchored on a tripod with the image already framed. Another function available on in some live view modes is the virtual horizon (see the virtual horizon chapter).

Other characteristics of the display

It is also useful for a display to have a large viewing angle, adjustable brightness in order to compensate for external light conditions as well as being resistant to scratches. Some models also have mobile displays that can be oriented as needed.

Introduction

The camera

How it is made a Reflex camera