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.
Summary: 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.
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 ...
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.