Electronic viewfinders are used on some cameras where an optical viewfinder would be impractical or undesirable. In the past, the quality of EVFs has been pretty low, but Epson has announced a new 800 x 600 pixel screen which could help change all that.

The point about the Epson display is that it has much higher resolution than usual. Most EVFs have just 0.23 megapixels and look pretty grainy, but this one has 1.44 megapixels and should look much sharper and smoother, helped by an ‘analog driver’ which produces smoother colour gradations.

This new technology could be highly significant for two types of camera: superzooms and hybrid D-SLR replacements.

Digital compact cameras with long-range zoom lenses, like this Nikon P90, cannot be fitted with optical viewfinders because they do not have an SLR viewing system, and the zooming range is too great for a separate, linked viewfinder. Instead, you get a second, smaller LCD display which you see through the viewfinder eyepiece. This is basically another, smaller LCD, just like the one on the back. Usually, the resolution is too low for accurate focussing or examining fine detail.

The most useful application for high-resolution EVFs, though, may be in hybrid D-SLR replacements like the Panasonic Lumix G1. Although it looks like an SLR, the G1 has no mirror. Here, you can see straight through to the sensor itself. During normal viewing, the image is formed on the sensor and transferred either to the LCD on the back or to the electronic viewfinder.

Hybrid cameras could eat into the D-SLR market quite quickly because they are mechanically simpler and better suited to live view and movie modes.

It may not be Epson’s new EVF that prompts the breakthrough, though, because displays with this kind of resolution have been done before. Panasonic already has a 1.44 megapixel EVF which it uses in the G1 and the GH1.

The extra resolution does make a huge difference to the quality of the image in the viewfinder, but it doesn’t solve all the problems of EVFs. Conventional optical viewfinders get their illumination from the subject itself, so their brightness always matches the conditions. EVFs, however, can get swamped in very bright light or prove too overpowering in dimmer conditions.