Sigma SD15 review

A small LCD screen (with a switchable backlight) displays information about exposure settings, including shutter speed, aperture, ISO, metering modes, exposure compensation and a number of additional functions. The optical viewfinder is a good size, offering 98 per cent frame coverage at a 0.9x magnification, making shot composition and focusing relatively simple, but there’s no Live View capabilities for fine tuning focus.

Instead, the rear 3in, 460,000-dot resolution display is only used for reviewing or trawling menus, meaning the now almost standard video recording capability is also absent. Despite these omissions, the essential functions are all present and the Quick Set (QS) button improves ease of operation as it allows you to change important camera settings with the press of a button. There’s also a ‘func’ button which makes more of the SD15’s functions readily available and also displays information about the camera’s current settings – it brings this up on the rear display as a virtual view through the optical viewfinder, complete with focus points.

Sigma claims that the Foveon X3 sensor helps to improve colour depth, but we felt that RAW files processed with Lightroom 3.2 were very washed out, lacking saturation. They needed a lot of tweaking to improve colour depth, which wasn’t what we were expecting.

With that said, the SD15’s metering system works well and produces good exposures most of the time. There were only a few occasions where the partial metering system didn’t recommend an accurate exposure and forced us to dial in exposure compensation. We felt confident that the SD15 would get the exposure right, which is important when you’re walking around with a camera.

Sensitivity ranges from ISO 100 to ISO 1600, which is expanded to ISO 50 and ISO 3200 if you’re shooting in RAW, but anything above ISO 800 really starts to lose the battle against noise. Colour shifting, banding and chroma noise start to appear at ISO 800 and are in full force at ISO 1600.

The result is gritty, almost dirty-looking images which are difficult to rescue with the excellent noise reduction algorithms built into Lightroom 3. The JPEGs aren’t much better either and are a little soft out-of-camera – they certainly benefit from some sharpening in Photoshop.

At almost £800 for just the body, Sigma’s SD15 is a tough sell because, while there’s an excellent range of over 40 lenses, its feature set is quite limited in comparison to its competitors. Some will undoubtedly love the fact that the SD15 doesn’t suffer from feature bloat and is clearly a camera aimed at shutter bugs, but others will hate its quirkiness.

In some instances, the SD15’s Foveon X3 sensor does make a telling difference to image quality, but in others it’s difficult to tell it apart from a similarly priced Canon or Nikon camera. What’s more, when you increase the sensitivity beyond ISO 400, the SD15 really comes a cropper against similarly priced cameras. At this price, you’re better off buying Canon’s EOS 550D if you want to take great pictures in a wide range of lighting conditions.