Unlike previous digital SLRs based around Canon, Nikon and Contax 35mm systems for their lens range, Olympus' interchangeable OM-series lenses were discontinued some time ago, so the E-1 is the first to adopt a new format called the Four Thirds Digital System.
A completely new digital SLR system has arrived in the shape of the Olympus E-1 and is perhaps the most eagerly awaited professional camera this year. Unlike previous digital SLRs based around Canon, Nikon and Contax 35mm systems for their lens range, Olympus' interchangeable OM-series lenses were discontinued some time ago, so the E-1 is the first to adopt a new format called the Four Thirds Digital System.

Optimised for digital photography, this new standard is open to other manufacturers by sharing a common lens mount, and the company claims several advantages over legacy systems. First, the image circle produced by the new lenses, which dictates the diagonal element of the image format, is almost half the size of the traditional 35mm format. This means smaller CCDs can be used without compromising the angle of view of wide-angle lenses, and there's less likely to be a loss of image quality at the edges and corners of the frame. Throw in lenses with twice the resolving power of conventional optics to maximise the performance of the electronic sensor, plus larger maximum apertures for low-light performance, and it's easy to see Olympus could be onto something. 

For the moment, though, Olympus is the first to market with the new system, and the E-1 uses an 18 x 13.5mm CCD designed specifically for still image capture with a maximum 5-megapixel resolution. The pixel count is down somewhat on the pro Nikon D100 and Canon EOS 10D, and even lower than Canon's sub-$2,000 EOS 300D (February 2004, page 54), but Olympus claims this shouldn't make much of a difference.

The basic specification, however, is aimed at professional shooters. The magnesium alloy body is sealed against the effects of light rain and dust, and this even extends to the lenses and lens mount, similar to some of the L-series pro lenses from Canon. And like the pro Canon EOS-1D and Nikon D1 models, the shutter has been tested for 150,000 cycles. The standard kit includes a Zuiko Digital 14-54mm f/2.8-3.5 zoom, which due to the sensor size becomes the desirable 35mm equivalent of 28-108mm f/2.8-3.5. 

So does the camera live up to all the hype? Well, the asymmetric-styled body is reassuringly sturdy and the quicker startup over the non-interchangeable lens Olympus E-20P, on which it's based, is an improvement, but its Achilles heel is immediately revealed when the viewfinder is placed to the eye. Auto-focus appears slower than its rivals and is detected from just three small selectable target areas, grouped horizontally in the central third of the frame. From a technical standpoint, this is far less ambitious tha its competitors, including the EOS 300D, and limits its versatility when tackling fast-moving subjects or taking a grab-shot. AF targets aside, we suspect focusing tardiness is due to the lens' internal driving mechanism, so it could be faster with others, but it's slightly disappointing nonetheless. 

In all other aspects, the camera is fast; once the lens is driven to the point of focus, it rarely hunts and shutter lag is practically non-existent. If set to continuous frame advance, two shots can be taken before you have time to react, almost belying the quoted 3fps rate. The 128MB buffer will accept 12 continuous frames, regardless of the file size or type - RAW, TIFF or JPEG - and there's a countdown shown in the full information viewfinder so it could be used for some sports or action sequences.

Manufacturers are realising that most users prefer selecting the various modes and features using a combination of traditional dials and buttons rather than a bottomless menu, and the E-1 subscribes to that point of view. Most of the day-to-day adjustments fall readily to hand, with the four exposure modes - manual, program (with shift), aperture priority and shutter priority - selected from a large lockable dial, although for some advanced features setting up is required first.

For example, the two top ISO-equivalent sensitivity settings of ISO 1,600 and an unbelievable ISO 3,200 have to be selected from the menu. Only then do they appear alongside the auto setting and manual range of ISO 100-800 in the large LCD panel on the top plate. They probably don't appear by default because noise is already noticeable at ISO 400. Using the noise filter greatly improves the image, but it's progressively less effective at the higher speeds. Also, it more than doubles the processing time, making you wait an age to review the image.

The E-1's auto white balance can be left alone in daylight, but it's not as impressive as the system adopted in the EOS 300D. However, there are plenty of presets available, plus a straightforward custom option using a small button located under the AF assist light on the front that works fine. 

Despite the slightly lacklustre AF system, the E-1 handles well and offers many professional features, most notably the tough build and fast optics. While we'd have preferred a higher-resolution sensor for some applications, the E-1 competes well with the likes of the EOS-10D and Nikon D100, both on image quality and price, although a CompactFlash card will have to be budgeted for. It may be early days for the Four Thirds Digital System, but despite our issues with AF the E-1 is nevertheless a remarkably competent performer.