Review based on a production Sigma SD10, Firmware Version 2.0.4.1642
On October 27th 2003 Sigma announced the new SD10. This new X3 based digital SLR is the successor to the SD9 which was the first digital camera to utilize Foveon's unique X3 sensor technology (info here). The SD10 has a Sigma AF mount and, like the SD9, a Foveon X3 10M CMOS Sensor* which has 2268 x 1512 x 3 photodetectors (three photodetectors for each pixel location). With the advent of the SD10 both Sigma and Foveon are taking the (braver but) more logical position of using the number 10 million to represent the number of photodetectors, I'm sure this decision will be debated ad nauseam but it's easy to see their position, in our previous experience the X3 sensor delivers approximately twice the resolution of a standard mosaic sensor with the same number of horizontal and vertical pixel locations.
* The sensor in the SD10 is an improved version of the Pro 10M named the F7X3-C9110
* It appears as though support is one thing, action something quite different
| Sigma SD10 | Sigma SD9 | |
| ISO sensitivity |
• ISO 100 |
• ISO 100 • ISO 200 • ISO 400 |
| Long exposures | • 15 sec at ISO 100 • 4 sec at ISO 200 to 800 • 30 sec in extended mode * |
• 15 sec at ISO 100 • 1 sec at ISO 200, 400 |
| Power | Single battery | Two battery sets |
| Exposure compensation | 1/3 EV steps | 1/2 EV steps |
| OK / Cancel buttons | Color coded red/blue | Both black |
| Wireless TTL flash | Yes | No |
| X3F embedded rendering data* | Yes | No |
| X3 Fill Light* | Yes | No |
* Extended mode
** Photo Pro 2.0 improvements
* Claimed
In the example below we are simplifying things by using a 130 x 130 sensor, thus a total of 16,900 pixel locations in the output image. Obviously the same rules apply no matter many pixel locations the final image has.
Traditional "Mosaic" sensors
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Digital cameras have for years used what is essentially a monochromatic (b&w) image sensor with individual color filters over each photodetector (known as the Bayer pattern and normally in a GRGB pattern). This means that each photodetector can only detect one of either red, green or blue light. Note that the green channel has twice the number of photodetectors as red or blue (this is because the majority of luminance information is carried in the green channel). A demosaic algorithm then combines the color of neighbouring pixels to reproduce the scene color at that pixel location.
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| Red 4,225 photodetectors |
Green 8,450 photodetectors |
Blue 4,225 photodetectors |
Output |
Foveon's X3 sensor
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Foveon's sensor instead of having a single photodetector at each pixel location has a multi-layered design which has the equivalent of a red, green and blue photodetector at each pixel location. This means that instead of having to interpolate the values of neighbouring pixels the X3 sensor 'sees' full colour at individual pixel locations. This is pretty much the 'holy grail' of digital image sensors, it should mean ultra sharp, detailed images with full color single pixel resolution.
Note that this is a simplified drawing of how the chip works, for more detail see our news article at the time.
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| Red 16,900 photodetectors |
Green 16,900 photodetectors |
Blue 16,900 photodetectors |
Output 16,900 pixel locations |
Because of the similarity between the SD10 and the SD9 (they're almost identical externally) the first half of this review (body, operation, menus etc.) is based on my SD9 review which was posted in November 2002.
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).
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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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This article is Copyright 2004 Phil Askey and the review in part or in whole may NOT be reproduced in any electronic or printed medium without prior permission from the author. For information on reproducing any part of this review (or any images) please contact: Phil Askey.
Sigma DP1x 14MP FOVEON CMOS Sensor Digital Camera and 2.5 Inch LCD | $372.00 |
Sigma SD9 3.54MP Digital SLR Camera | $224.99 |
Sigma DP1 14MP Digital Camera | $549.99 |
Sigma DP1s 14MP Sensor Digital Camera | $539.75 |
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