Preview based on a pre-production SD1 with firmware 0.94The SD1 created a great deal of interest at Photokina 2010. Having used Foveon's original 4.7x3MP sensor in its SD and DP series of cameras, Sigma bought the sensor company in 2008 and instructed it to focus its efforts on high quality stills photography - specifically the 15x3MP sensor that the SD1 is built around. Now, not long after the originally-proposed launch date, the SD1 is here. The first thing to be addressed has to be the price, and let's not dance around this: the SD1 is eye-wateringly expensive. Even with Sigma listing lens kits for pre-order at significantly below its own suggested price for the body alone, it's still a hugely expensive piece of kit. The company is talking in terms of the SD1 being a portable alternative to medium format cameras (which may not be entirely unfair, as the sensor has the potential to produce resolution similar to a 30MP Bayer-type sensor). Ultimately, the entire research and development cost of the sensor has to be recouped from the number of cameras the company expects to sell and, sadly, the MSRP suggests that Sigma only expects to sell medium format quantities. You could, of course, argue that it might sell twice as many if it sold them for half the cost, but that isn't the tactic Sigma has chosen. To look at it another way, the company has decided it has a better chance of charging a premium over Nikon D3X money and selling a handful of cameras, rather than charging the D300 price-tag many existing users were hoping for and have to sell mass-market volumes. It doesn't make sense to dwell much further on this decision, no matter how self-fulfilling it seems. Instead we'll take a look at the camera, what it offers and how it behaves. Obviously the SD1's defining feature is the new 15x3MP Foveon sensor. For those of you who haven't come across the technology before, it uses a fundamentally different method for detecting color than any other camera sensor. Almost all other cameras place a pattern of colored filters in front of their sensors so that each individual photo site is only receives either red, green or blue light. To create a full-color pixel in the final image, clever mathematics is applied to estimate the values of the two unmeasured colors, based on the amount of those colors captured by adjacent photos sites. Foveon's technology doesn't use filters - instead it uses the fact that different colors of light have different amounts of energy. As a result, different colors of light can penetrate silicon to differing extents. Foveon's chip measures the number of photons captured at three different depths in the photosite - depths corresponding to how well Red, Green and Blue can penetrate the chip. The main advantage of this is that, unlike other digital cameras, the Sigma measures all three colors at every one of its 15 million photo sites, capturing three times as much color data per-pixel as a conventional sensor. (Hence the company's reference to it being a 46MP camera). Because the Foveon sensor captures full color data at each pixel location, it's not susceptible to color moiré - false color patterns that are the result of those clever calculations occasionally getting things wrong, for example with finely-woven fabrics. Traditional Bayer-pattern sensors suppress this by using an optical low pass (or anti-aliasing) filter that slightly blurs the image at the pixel level, reducing the camera's resolution. The Foveon sensor doesn't use an AA filter, and is therefore able to resolve substantially more detail than its pixel count alone might suggest. Beyond that, the SD1 is a camera with a solid specification, though not one that would stand out in the enthusiast-grade DSLR sector, much less so when pitched at the price of the likes of Canon's EOS-1Ds series and Nikon's D3X. The other potential hurdle for the SD1 is its use of Sigma's own SA lens mount. The company builds a wide range of lenses for the mount, but a question mark has to hang over how many of them will live up to the standard demanded by a $9,000+ camera, and how many people will be willing to risk spending money building up a collection of lenses for a non-mainstream mount. It's also worth noting that very few of Sigma's lenses offer any form of weather sealing. Sigma SD1 specification highlights- 15x3MP Foveon X3 CMOS sensor
- ISO 100-6400
- 11-point AF sensor (all cross-type)
- 5 frames per second continuous shooting
- 460,000 dot LCD screen
- Shutter capable of 1/8000th second and rated for 100,000 cycles
- Per-lens AF fine tuning
If you're new to digital photography you may wish to read the Digital Photography Glossary before diving into this article (it may help you understand some of the terms used).
Conclusion / Recommendation / Ratings are based on the opinion of the reviewer, you should read the ENTIRE review before coming to your own conclusions. Images which can be viewed at a larger size have a small magnifying glass icon in the bottom right corner of the image, clicking on the image will display a larger (typically VGA) image in a new window. To navigate the review simply use the next / previous page buttons, to jump to a particular section either pick the section from the drop down or select it from the navigation bar at the top. DPReview calibrate their monitors using Color Vision OptiCal at the (fairly well accepted) PC normal gamma 2.2, this means that on our monitors we can make out the difference between all of the (computer generated) grayscale blocks below. We recommend to make the most of this review you should be able to see the difference (at least) between X,Y and Z and ideally A,B and C. |
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Just posted! Our hands-on preview of Sigma's flagship SD1 DSLR. With its unique 15MPx3 Foveon X3 sensor that captures full color detail at each pixel location, the SD1 caused a something of a stir when it was first announced at Photokina 2010, and possibly an even bigger one when its eye-watering price was revealed recently. We've been lucky enough to get hold of a rare pre-production camera, and have prepared a hands-on preview detailing its design and operation.
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