Andy Westlake tests Sigma’s unconventional SA-mount mirrorless camera, the sd Quattro
Sigma sd Quattro review: Introduction
At a glance:
Foveon X3 Quattro APS-C sensor
£799 body only
£999 with 30mm f/1.4 lens
Sigma is best known as a leading third-party lens producer, but it also has a long history of selling cameras. Having made a couple of 35mm SLRs with its proprietary all-electronic SA lens mount, its first DSLR appeared in 2002, based around the unique triple-layer Foveon X3 sensor.
While it has understandably not been very prolific with new models, Sigma has maintained a constant, if low-key presence in the camera market. Its current dp Quattro fixed-lens compacts have a clear, if somewhat niche appeal, with exceptional lenses and superb image quality at low ISOs. The camera we’re considering here, the sd Quattro, uses the same sensor, but with interchangeable lenses. It’s one of a pair of externally identical cameras, with the sd Quattro-H differing in having a larger, higher resolution 25.5-million-pixel sensor with a 1.3x crop.
With the new model, it appears that Sigma has learned some difficult lessons from its experience with the ill-fated SD1 DSLR of 2010, which was underpowered and overpriced. First, with a body-only price of £799, the new sd Quattro is much more reasonably priced. Second, while it’s based around the same SA mount, the model is not an SLR at all, but a mirrorless camera with an electronic viewfinder.
So what does this mean? When you remove the lens and look inside the mount, there’s no mirror, just a deep empty tube back to the camera’s sensor. This is normally exposed with the shutter open, so it can provide a full-time, live-view feed to either the rear screen or the eye-level viewfinder. The advantage is that the camera’s mechanical complexity is greatly reduced (and therefore its cost); yet it retains the ability to use all the SA-mount lenses Sigma has made over the years. The disadvantage is that you get little of the size and weight saving typical of CSCs.
Sigma isn’t the first company to try building a mirrorless camera around an SLR mount; the self-consciously quirky Pentax K-01 used the same concept. However the sd Quattro has altogether higher aspirations to be a serious photographic tool. While it’s much more affordable than its predecessor, it’s still in the same price bracket as hugely capable enthusiast-level DSLRs and CSCs such as the Nikon D7200 or Olympus OM-D E-M5 Mark II. So, has Sigma done enough to make it a competitive alternative?