It’s hard to think of a feature that used to polarise opinion as much as electronic viewfinders. For quite some time, these were simply too small, too low in resolution and just not clear enough to present a scene as clearly as an optical viewfinder would. They weren’t 'real' viewfinders, people would argue, just a novelty found in bridge and superzoom cameras. Add to this graininess in low light and a lagging as you moved around the scene, and it was easy to see why they had a lot of detractors.
Mirrorless cameras are designed in a way that means they cannot use the same optical viewfinder as a DSLR, one that takes its view through the mounted lens. Instead, many mirrorless cameras have electronic viewfinders, and some that don’t allow you to attach separate units through a hot shoe on their top plates. This is one area in which manufacturers have worked hard to get them to the same level as optical ones, and although many would argue that they fall short, it’s difficult to deny how much progress there has been here.
Electronic viewfinders today offer a magnification that rivals those of optical viewfinders inside DSLRs, and lagging is less of an issue than it used to be thanks to faster refresh rates. The most recent area of focus for manufacturers has been in the blackout effect you would typically see when shooting continuous bursts of images. Sony has successfully managed to eliminate this on its A9 model, and Panasonic is now claiming the same for its G9 model (which, at the time of writing, we have yet to review).
Of course, on top of all this, electronic viewfinders continue to offer the same benefits they always have. The ability to view the image with any changes to exposure, white balance, colour settings and so on applied instantly, for example, something optical viewfinder cannot do. Furthermore, they always offer a 100% view of the scene, something that’s usually reserved for enthusiast and professional DSLR bodies, but omitted from entry-level ones.
Most electronic viewfinders can also be successfully used to show a more balanced view of the scene in low light – very much an underappreciated benefit – and the best examples are clear and largely free from noise in even these conditions.
Optical viewfinders have themselves become more intelligent. Illuminated LED panels overlaid on the main frame, for example, allow for more information to be visible within them than ever before. This is the principle behind Canon's Intelligent Viewfinder technology. Many photographers also enjoy the fact that they continue to show something that’s more lifelike than what an electronic viewfinder will present, even if this doesn’t make things any easier in darker conditions.
Perhaps the last major hurdle for manufacturers is something those using optical viewfinders never need to think about, namely the ability for the viewfinder to be activated the moment you need it. Many people that use a camera with an electronic viewfinder have it set up so that the feed alternates between the rear LCD screen and the viewfinder as the camera senses the user’s face moving closer to, or further away from, the camera, and even pricier models can have a slight delay here. Minor delays are also commonly encountered right after you power up a camera, or during certain aspects of operation, and so optical types found on DSLRs do still have quite a key advantage here.