Conclusion - Pros

  • Exceptional image quality at low ISO, especially in Raw mode
  • Very good build quality (including weatherproofing)
  • Straightforward operation, with external controls for all key functions
  • Large, clear viewfinder
  • Excellent grip, extremely comfortable to shoot for extended sessions
  • Near-perfect implementation of mirror lockup (for tripod work)

Conclusion - Cons

  • Extremely slow file write speeds, with erratic control behaviour while writing
  • Poor image quality at high ISO, with green and purple colour blotching in shadows
  • Evaluative metering somewhat prone to highlight clipping
  • Overly-conservative highlight clipping warning (can encourage underexposure)
  • No Live View (which makes accurate manual focus harder than it could be)
  • Unimpressive AF compared to similarly-priced competitors
  • Twin controls dials largely wasted, with duplicate functions in all modes except M
  • Uncomfortably-placed ISO button
  • ISO not displayed full time in viewfinder
  • Camera does not achieve specified continuous shooting speeds (about 1 fps slower in our tests)
  • AB configuration position on drive mode dial locks all other functions, and prevents shooting
  • Sigma Photo Pro software is slow and painful to use, and lacks standard controls such as cropping, straightening and lens corrections

Overall conclusion

The SD1 is, overall, quite straightforward to summarize - it's a camera that offers exceptional low ISO image quality in a competently-performing but quirky body. Its 15x3 MP Foveon sensor is capable of delivering wonderfully-detailed images, with a subtlety of colour rendition that has to be seen to be appreciated. But this is offset by painfully slow file write times during which the camera behaves erratically, distinctly sub-par image quality at ISOs over 800, and a no-frills camera body that doesn't even offer live view for tripod work. An all-rounder it is not.

To get the most out of the SD1, you also need to shoot Raw, but at the moment (and, as far as we can tell, for the foreseeable future) this locks you into using Sigma Photo Pro to process your images. Mainstream third-party converters from the likes of Adobe don't support the SD1. Like the camera itself, Sigma Photo Pro is slow, quirky and exasperating, but capable of excellent results if you have the time and patience to get the most from it.

Image Quality

At low ISOs - say 100 to 400 - the SD1's image quality is simply stellar. Detail resolution and rendition is remarkable, thanks to the lack of an anti-aliasing filter in front of the sensor, and the default colour output is subtle and natural-looking. Of course there's always an argument that for many purposes photographers don't really want natural colours - Fujichrome Velvia would never have sold a single roll if they did - but the SD1's files also provide a good start point for boosting colour to your heart's content. Image quality quickly deteriorates at higher ISOs though, with unpleasant green and purple colour blotching in the shadows that spoils files at ISO 1600 and higher.

The SD1's out-of-camera JPEGs are full of detail but they're really best treated as proofs, with their main problem being a propensity towards highlight clipping. This is due to a combination of slightly limited highlight range and evaluative metering that's very strongly linked to the selected AF point, and therefore prone to overexposure if you focus in a dark region of the frame. Of course when shooting Raw files you can recover some 'lost' highlight data, particularly at ISO 200 and above.

However, the SD1's unique sensor means that Raw processing support is limited to Sigma Photo Pro. This is basic but competent software that's capable of giving excellent output, however it takes far too much of your time to do so, with a workflow that feels hopelessly outdated, and a limited feature set that virtually guarantees a trip into Photoshop. The SD1/Sigma Photo Pro combination is not one we'd recommend if you have to process hundreds of images quickly.


The SD1's handling is something of a mixed bag. It's an extremely well-built camera that feels solid in your hand, with an unusually good grip that's very comfortable during extended shooting sessions. Almost all key photographic functions have external control points, and for less-frequently changed options there's not just one, but two onscreen control panel interfaces providing quick access. Overall this means you very rarely have to pay a visit to the menus, and even when you do they're mercifully short and well-organised. On paper, this means that the SD1 ticks all the right boxes.

The camera is however let down by a few quirks and odd design decisions. For example, the twin control dials are wasted much of the time because they are, quite literally, twinned - they almost always do exactly the same thing. They're only fully-employed in Manual exposure mode; in the PAS modes both control the primary exposure parameter, and to set exposure compensation you have to hold down the +/- button and spin the rear dial. We also find the ISO button to be poorly-placed, demanding a cramped and uncomfortable hand position to make changes, as again you have to hold it down while simultaneously turning the rear dial. You get used to these irritations in time, but they still mean that the SD1 is a bit less-pleasant to shoot with than its competitors.

The biggest operational problem with the SD1, though, is how it handles image file writing and review. Its Raw files are huge - up to 50 MB - and the camera takes fully 15 seconds to write one to card, during which time its response to buttons is distinctly erratic. Some buttons don't function at all, while others work during only part of the file writing process. For a camera that's priced in the same range as super-slick top-end APS-C SLRs, this kind of buggy and unresponsive operation is a distinct drawback.

If you tend to shoot a lot in continuous drive mode, then the SD1 probably isn't the camera for you. Its slow write times mean it will lock up for an inordinate amount of time after firing off a full burst - well over a minute for 7 full resolution Raws, and fully 2 minutes for 14 medium resolution Raws. No matter how we try, we can't get it to shoot at its specified speed either, but about 1 fps slower (so 4fps at full resolution).

The SD1 also prevents you from quickly reviewing images to check for focus and exposure while it's writing to card - instead you have to wait until it's finished to enter playback mode. If you've shot four or five images in quick succession, this process can easily take a whole minute. Overall this makes shooting with the camera a somewhat exasperating experience, and again, simply not as refined as we've come to expect from a modern camera.

The Final Word

The SD1 is an intriguing camera, with one exceptional strength - its stellar low ISO image quality - that comes at the expense of substantial operational compromises and poor high ISO image quality. The problem it therefore faces is that the similarly-priced top-end APS-C cameras it competes against, such as the Canon EOS 7D and Sony Alpha SLT-A77, are superb all-rounders with no such glaringly-obvious flaws. This means that, with the best will in the world, it appears set to be a niche product that will be most-appreciated by a relatively small group of photographers specializing in areas that can make the most of its strengths, such as landscape and studio work, while being least-disadvantaged by its operational quirks.

However despite its undeniable weaknesses, there's little doubt that if it meets your needs the SD1 has the potential to be an excellent photographic tool. Existing Sigma users with a set of lenses will surely find the resolution a huge step up over previous models, while appreciating that the unique 'Foveon look' hasn't been sacrificed in the process. But while Sigma has to be applauded for continuing to develop the Foveon sensor, we can't help but feel that the SD1's lack of refinement limits its overall appeal.

Please note that because of its unconventional sensor and feature set the SD1 is a difficult camera to score, and in some respects fits awkwardly alongside its peers when their scores are compared. As such (and as always) for a complete picture of how the SD1 performs, we encourage you to read this review in its entirety.

Scoring is relative only to the other cameras in the same category.
Click here to learn about the changes to our scoring system and what these numbers mean.

Sigma SD1
Category: Semi-professional Interchangeable Lens Camera / DSLR
Build quality
Ergonomics & handling
Metering & focus accuracy
Image quality (raw)
Image quality (jpeg)
Low light / high ISO performance
Viewfinder / screen rating
The SD1 is a no-frills SLR with a very basic feature set that offers exceptional image quality at low ISOs (100-400). However, it's let down by slow file write times and erratic control behaviour during this process. High ISO image quality is unremarkable, and there's no live view for tripod shooting. It's a specialist tool, but if you can live with its limitations it's capable of excellent results.
Good for
Photographers looking for exceptional low ISO image quality, and willing to spend the time processing RAW to achieve it.
Not so good for
Sports, action, or any kind or photography requiring high ISOs
Overall score

Recommended links

Want to make sure you don't miss out on any future articles?
Sign up for our free weekly newsletter!

Enter the 'Sigma SLR Talk' Discussion Forum