Sigma SD Quattro
|File:Sigma sd Quattro front-left 2016 China P & E.jpg|
|Lens mount||Sigma SA Mount|
|Image sensor type||Foveon_X3_sensor|
|Image sensor size||23.5 × 15.5 mm (H 26.6 × 17.9 mm)|
|Maximum resolution||5,440×3,616 (H 6,200×4,152)|
|Film size||APS-C (H APS-H)|
|ASA/ISO range||100 - 6400|
|Recording medium||SD, SDHC, SDXC|
|Focus||Phase difference detection system + Contrast detection system|
|Focus modes||M, AF-S, AF-C|
|Focus areas||9 points select mode, Free move mode|
|Exposure bracketing||3 or 5 shots in 1/3EV steps|
|Exposure modes||P, A, S, M|
|Metering modes||Evaluative Metering, Spot Metering, Center-Weighted Average Metering|
|Shutter speeds||1/4000 - 30 sec., Bulb|
|Rear LCD monitor||2.3mp|
|Dimensions||147mm/5.79″(W) × 95.1mm /3.74″(H) × 90.8mm/3.57″(D)|
|Weight||625g without card and battery (H 635g)|
The 'sd Quattro' and the variant 'sd Quattro H' are mirrorless system cameras of the Japanese company Sigma. They have, like the dp2 Quattro, the new sensor Foveon X3 Quattro, but with 33 or 45 effective megapixels (39 or 51 megapixels Bayer equivalent).
The Sigma sd Quattro and sd Quattro H main feature is the Foveon X3 Quattro Image Sensor.
The original idea behind this Sensor design is, that different thick layers of silicom absorb different wavelengths of lights. This allows 3 Sensors to be stacked over each other to record every color on every pixel
This drastically increases color reproduction, color resolution and color contrast to create images an Bayer Filter Array Sensor can not produce.
But this Sensor design also does have its downsides, especially the last generation, 46 Megapixel Foveon X3 APS-C Sensor where hit by these issues due to its high megapixel count.
As the first layer already absorbs an big amount of light, the other two layers are more prone for image noise as they received less light and so to be pushed more. Another issue was duplicated data. In demonstration images it is shown that each layer records one color, but that is actually very simplified. Every Layer records all wavelenghts of light to an certain amount, which needs to be separated by the Image Processor in the Camera.
This reduces the already rather slow speed the camera had to deal with due to the high number of megapixels. That way, the last generation of Foveon Sensors needed 46 Megapixels to archive an 30 Megapixel Bayer Equivalent Image Resolution
In the new Foveon X3 Quattro Sensor, the main target was to better use the already captured wavelengths in the top layer (also called blue layer), so the second and third layer needed less megapixels.
SIGMA came to the conclusion that the second and third layer only needed 1/4 of the pixels and it would be still possible to seperate all colors at all pixels in the final image (The name Quattro was choosen due to the 4-times higher megapixel count in the top layer in this design).
This improves the noise levels on the second and third layer to an extend, where it enabled SIGMA to further increase the resolution of all layers to provide an higher image resolution, and decrease the noise level at the same time.
The Information saved in the top layer is applied to the second and third layer and so, in the image processing, cause all 3 layers to have the same megapixel count of 20 megapixels.
This way the Foveon X3 Quattro Sensors needs to capture 29 Megapixels to provide an 39 Megapixel Bayer Equivalent Resolution, compared to the 46 Megapixels the SD1 needed to provide an 30 Megapixel Bayer Equivalent resolution
- Foveon X3 sensor CMOS
- Total pixels: approx. 33 MP, variant H 45 MP
- Pixels in layers: O (top): 5,424x3,616 / M (center): 2,720x1,808 / U (bottom): 2,720x1,808,
- Raw output level high O: 5,424 × 3,616 / M: 2,712 × 1,808 / U: 2,712 × 1,808
- Raw output Level low: O: 2.704 × 1.808 / M: 2.704 × 1.808 / U: 2.704 × 1.808
- Variant H:
- Pixels in layers: O (top): 6,200 × 4,152 / M (center): 3,348 × 2,232 / U (bottom): 3,348 × 2,232
- Raw output level high: O: 6,192 × 4,128 / M: 3,096 × 2,064 / U: 3,096 × 2,064
- Raw output Level low: O: 3.088 × 2.056 / M: 3.088 × 2.056 / U: 3.088 × 2.056
- Edition Jpeg:
- s-hi for 3: 2 with 7,680 × 5,120 (H: 8,768 × 5,840) = extrapolated
- high for 3: 2 with 5,424 × 3,616 (H: 6,192 × 4,128) = native blue (above)
- low for 3: 2 with 2.704 × 1.808 (H: 3.088 × 2.056) = native green-red (middle-bottom)
- s-lo for 3: 2 at 1,920 × 1,280 (H: 1,920 × 1,280) = reduced to Full HD
- 7.6 "(3 inches) TFT color LCD monitor
- Exposure index: ISO 100-6400,
- Exposure compensation ± 5 EV changeable in 1/3-EV increments
- Supported file formats: Lossless compressed RAW data (14-bit), JPEG (Exif 2.3), Adobe DNG (12-bit)
- Li-ion battery BP-61
- Weight about 625 g (without battery and memory card)
- Sigma SA interchangeable lenses compatible with the SD series
- current firmware: ex works
Li-ion battery BP-61, battery charger BC-61, USB cable, power supply CN-31
Power supply SAC-7, Powergrip PG-41, Remote control CR-31, Flash-USB-Dock FD-11, Plug-on flash EF-140S SA-STTL (Guide number 14 at ISO 100 / m)
The camera has a hot shoe, which is compatible with several Electronic Flash like the EF-610 or EF-630.
Sigma Photo Pro
In addition to the new SD Quattro, the software will be available for the Sigma DSLR cameras SD9, SD10, SD14, SD15 , SD1 Merrill and the Sigma DP Series including the Sigma DP Quattro DP0 to DP3 ( dp0 Quattro, dp1 Quattro, dp2 Quattro and dp3 Quattro).
The two camera variants have a SIGMA SA bayonet and these are compatible with all SIGMA SA interchangeable lenses. They are thus a cross between the two camera series Sigma SD and Sigma dp Quattro and should combine the advantages of the two series.
- "Inside Story" SIGMAs Inside Story about the Foveon X3 Sensor
- "Foveon X3 Difference"Comparison of Foveon X3 and Bayer Filter Array Sensors
- Several Online Reviews and every owner of an SIGMA SD1 can verify this
- "Sigma SD1 Merrill Review" Sigma SD1 / SD1 Merrill In-depth Review
- "Imaging excellence" Sigma SD1 Merrill Speical Content]
- "Quattro Sensor Design" Explanation of Quattro Sensor Design
- "sd Quattro Features" Information about the new sd Quattro Features
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