Summary: Conclusion The Sigma SD1 Merrill is a contradiction. It's a well-constructed DSLR with good ergonomics, a useful quick-set menu and great image quality thanks to its use of Foveon technology. However the camera's performance is hampered by auto focus problems in low light and all-too-frequent writing to the memory card that causes the camera to freeze until the writing is completed.
Conclusion: Both delightfully simple and deeply frustrating, the Sigma SD1 Merrill is the Jeckyll and Hyde of DSLRs. For photography in good light at low ISOs it's absolutely terrific. For everything else, it's just OK.
Summary: The SD1 is a non-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.
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)
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 ...
Conclusion: The Sigma SD1 Merrill is built around the uniquely designed image sensor, but a high price, sluggish performance and a time-intensive Raw workflow make it a difficult sell to all but the most devoted Foveon disciples.
Pros: Excellent build quality. High-quality viewfinder. Good control layout. Unique sensor design. Infrared shooting capability.
Cons: Expensive. Sluggish performance. Subpar LCD. Substandard JPG output. Difficult Raw workflow. No video support.
Summary: There is no doubt that the Sigma SD1's unique Foveon X3 sensor means that the final images from this camera in a variety of settings stand out from the other two models - for good and bad reasons. The SD1's resolution detail at lower sensitivities is truly staggering, although it is no match for the 40-million-pixel 645D.
There is a clear gap between each of the three cameras in this investigation.
Unfortunately, there are more areas where the SD1's sensor falls short.
Excerpt: Because of the status that the new Sigma SD1 Merrill has carried with it since it was unveiled last year, it's easy to get lost in the hype of the Foveon sensor technology, so let's cover it first to get it out of the way. Anyone interested in buying this camera will likely know how the Foveon sensor works. However, there will be a few who don't so for their benefit, we'll try to relay it in layman's terms.
Conclusion: In terms of specification, the Sigma SD1 Merrill might lack the finery of other cameras at this price point, but its stripped back set of controls is refreshing. Its limitations do mean that this isn't a camera we can recommend as an all-rounder, though. If you're after a DSLR that offers high resolution, high speed and high-spec features, look at the Canon 5D Mark III or Sony Alpha A77 instead.
Excerpt: Fast-forward to the beginning of 2012 and what is essentially the very same camera, albeit rebranded as the SD1 Merrill, is available for a fraction of that price – though at £1850 it’s still the most expensive APS-C DSLR on the market by quite a margin.
Pros: Detail and sharpness (at ISO 100), removable IR filter; well matched to serious studio pros using ISO 100 & controlled light
Cons: Expensive; very poor high ISO quality; poor auto white balance; slow processing; no live view; unlikely to meet amateur users’ demands
Excerpt: The Sigma SD1 is Sigma's update to their DSLR line and rather than a direct follow on from the SD14 / SD15, this camera has an all new 15.6 megapixel Foveon sensor. Each pixel records Red Green and Blue* and therefore Sigma call it a 46 megapixel sensor (15.6x3). The Sigma SD1 was first shown at Photokina 2010 (Oct) and then wasn't available to purchase till June/July 2011. The camera also had an RRP of £6199 including VAT making it quite an expensive investment!
Pros: Foveon Sensor, Weather sealed magnesium body, Removable IR Filter / Dust Shield for IR Photography, Very high pixel level detail, Strong colour available from the camera
Cons: Noise on JPEGs, High price, Only 1 Memory card slot (unlike other Pro cameras with dual slots), Lacks top LCD screen, or eye detection, Lacks video mode / live view, Sigma Pro Photo 5.0 Raw Conversion software slow, Slow to write to memory card, Poor battery life
Conclusion: The SD1’s impressive sensor technology puts this camera up in the big leagues with other pro camera kits. Although image quality and size is incredible there are still a few areas that could be improved.