Many digital cameras are equipped with an electronic viewfinder, which displays the scene over a second, small display to the viewer.
With the upcoming mirrorless interchangeable-lens cameras, also known as compact system cameras (CSC), the electronic viewfinder moved more and more into focus. In relation to the optical viewfinder, the digital form of representing the scene had no easy start. Even today many photographers prefer the classical DSLR viewfinder. But over the years the technology was enhanced and caught up. In addition, the electronic alternative comes up with many advantages.
Mirrorless interchangeable-lens camera
Due to their components, digital single-reflex cameras are quite large and have some more weight. On a trip, the equipment can quickly become massive and heavy, depending on how much lenses you carry around. For this reason, many photographers now rely on mirrorless cameras. The compact models spare the oscillating mirror, thus they become smaller and lighter.
But how can the subject be seen when there is no mirror system and thus no optical viewfinder?
First, it should be mentioned that not all mirrorless cameras have a viewfinder. In this case the scene can be viewed and the image can be composed via the Live View display. With the help of the camera sensor, the subject in front of the camera is brought to the monitor. Therefore, the sensor transfers the incoming light information to the monitor and so the scene can be seen almost instantly.
Strong sunlight/ backlight
The Live View display may be sufficient, but can have disadvantages in strong sunlight or backlight. Depending on the angle of the light, bright light conditions may complicate the framing via the LCD monitor. Some monitors are tiltable and/or rotatable and can be adjusted for observation. But this does not always improve the view. For such situations many photographers prefer a viewfinder. If you look through the ocular, the motive can be seen without influence of the surrounding light situation.
It is not surprising that most mirrorless cameras also have a built-in viewfinder or can be upgraded with one.
Electronic viewfinder – EVF
Since compact interchangeable-lens cameras do not include an oscillating mirror, the direct transmission of light to the viewfinder is not possible as it is the case with digital SLR cameras. Thus, they do not have an optical viewfinder, but an electronic viewfinder – EVF. The current scene is played back with the help of the camera sensor. This enables photographers to choose whether they prefer to frame the scene via the display at the back of the camera or via the EVF, which is equipped with a second small display (LCD / OLED) that is located in front of the ocular.
The data transfer and the processing of the displayed live scene on a display takes a bit more time compared to the representation via the optical viewfinder. This results in temporal delays* in the electronic viewfinder or the rear display. This is no problem as long as a still subject is viewed and captured, but when framing a fast moving subject, the right exposure moment might be missed by a fraction.
As a result of the technical development the time-delay has been decreased and, depending on manufacturer and model, is hardly recognizable. However, it cannot be reduced completely. So in terms of speed the optical viewfinder is a better choice because it displays the subject to the viewer in real time.
*The time delay can vary, depending on manufacturer and camera model resp. the built-in viewfinder.
Electronic viewfinders show the live scene to one hundred percent. A cropped image display like it can occur with optical viewfinders that have a smaller frame coverage, does not exist. Thus the view through the electronic viewfinder always gives back the exact section, which is later recorded by the camera.
An advantage compared to the optical viewfinder of lower and mid-price cameras that electronic viewfinders can claim for themselves. Because the frame coverage of these DSLR models often is 95 %, which complicates the image composition.
Other advantages electronic viewfinders offer is the rendering of the applied camera settings and effects in the viewfinder. If, for example, the white balance is adapted or effects are applied, it is visualized in the display instantly. This is possible, because the information shown in the EVF comes directly from the imaging sensor and includes the selected camera settings. This delivers a good preview of the final image. In addition EVFs can display a wide range of additional information like a real time histogram and camera settings. This enables photographers to alter settings like shutter speed, aperture, ISO, white balance, scene mode and effects while looking through the viewfinder and concentrating on the image composition.
Furthermore, the recorded images can also be reviewed and enlarged for proper examination in the EVF. This proves advantageous in difficult light situations. For example, if mirroring on the large rear monitor complicates the assessment, the playback over the viewfinder is a helpful alternative.
However, the electronic viewfinder still has some disadvantages. Besides the already mentioned time-delayed display, the digital viewfinder image requires additional power. That means that the battery life of the camera also is claimed. Also when doing some extended shooting sessions and looking through the EVF for a long time, the eye might get tired quicker compared to using a camera with an optical viewfinder. But with its one hundred percent life playback of the later recorded image, many photographers do no longer want to miss the electronic viewfinder.
Pros and cons of electronic viewfinders
- 100 percent representation of the motive.
- Applied settings and effects are taken into account in the viewfinder image. The photographer sees what the later photo looks like.
- Viewfinder image can display further information.
- Playback of images under difficult light conditions.
- Smaller and lighter cameras can be realized through the absence of the oscillating mirror.
- Shorter flange focal distance (aka flange back distance) enables adapting a wide range of 3rd party lenses with a dedicated adapter.
- Time-delayed viewfinder image visualization (depending on the manufacturer and model) → can lead to wrong exposure moment at fast moving subjects.
- EVF needs additional power.
Agony of choice
The decision on purchasing a camera can depend on several factors. Whether size, functions, image quality or viewfinder, according to the criterion it can be decided if it should be a digital SLR camera or a mirrorless system camera. If the optical viewfinder is an important point, the selection comes quickly on a DSLR. Especially photographers who deal with fast-moving subjects and who are up to sports and animal photography, appreciate the unaltered real-time subject preview. Thanks to this the release of the exposure only depends on the photographer and is not affected by a time-delayed view.
If a compact and lighter camera model is desired that allows changing the lens, it is worth to look at the great choice of mirrorless interchangeable-lens cameras. Depending on the price segment, quality and functionality, one can choose between a device with or without integrated electronic viewfinder or for one with an optionally attachable viewfinder. If you do not want to miss the ocular preview, a mirrorless camera with an integrated viewfinder would be recommended. Whether big, small or fast-reacting, who wants to be safe with the viewfinder, throws a look at the viewfinder image and the camera before buying. Only components and functions that personally convince, bring fun and will often be used in practice.