Digital Camera Information

Sigma has just released a new lens with an 11.1 high zoom ratio which is designed exclusively for digital SLR cameras and incorporates Sigma’s original OS (Optical Stabilizer) technology. With the optical stabilizer, the system uses two sensors inside the lens to detect vertical and horizontal movement of the camera by moving an optical image stabilizing lens group, to effectively compensate for camera shake. It also automatically detects movement of the camera and compensate for camera shake when shooting moving subjects such as motor sports.

Therefore it is perfectly suitable for low light conditions, indoors, at dusk and telephoto range. SLD (Special Low Dispersion) glass and aspherical glass provide excellent correction for all types of aberrations. This lens has a minimum focusing distance of 45cm (17.7”) throughout the entire zoom range and has a maximum magnification of 1:3.9. The inner focusing system is suitable for using a petal-type lens hood supplied and also circular polarizing filters.

The only problem is the price which is a little bit more expensive at $820.

Specifications

Focal Length: 18-200mm
Minimum Aperture: F22
Lens Construction: 15 Elements in 13 Groups
Angle of View: 69.3 - 7.1 degrees (Sigma SD format)
Number of Diaphragm Blades: 7 Blades
Minimum Focusing Distance: 45cm / 17.7 in.
Maximum Magnification: 1:3.9
Filter Size: Diameter 72mm
Lens Hood: Petal Hood
Dimensions: Diameter 79mm X Length 100mm
3.1 in. x 3.9 in.
Weight: 610g / 21.5 oz.
Corresponding AF Mounts:

SIGMA(coming soon)
CANON (available)
NIKON (coming soon)

Photozone.de has an excellent review on the Sigma AF 17-70mm f/2.8-4.5 DC lens which is one of many standard zooms available for Nikon DSLR users. Compared to the rest of the gang it offers a relatively long zoom range (~ 4 x ratios) combined with a relatively large max. aperture at 17mm.

They write: “The Sigma AF 17-70mm f/2.8-4.5 DC is a very good standard zoom and a viable alternative to the Nikon offerings in this range. Generally it is capable to produce very sharp results although the corner performance leaves a bit to be desired at 17mm at large aperture settings. The vignetting level could also be a bit better here but most competitors don’t offer an f/2.8 settings anyway and from f/4 it follows the mainstream. The level of distortions is about typical for a standard zoom whereas chromatic aberrations (color shadows) are comparatively low. The build quality is very fine for a lens in this price league.”

Source

After a long 3 years, Sigma will be releasing a new DSLR called the SD14 on the 26th September 2006. The new Sigma SD14 replaces the Sigma SD10 which is the only DSLR in the world to incorporate the Foveon X3 CMOS sensor.

Rumors has it that the new Sigma SD14 will have a 14 megapixel sensor. I have always admired the Foveon X3 sensor and I’m a bit surprised it has not been used in other DSLR.

The Foveon X3 sensor is different in that it captures all RGB colours at each and every pixel. The sensor features three silicon-embedded layers of pixel sensors, stacked to take advantage of silicon’s ability to absorb red, green, and blue light at different respective depths. This results in more accurate colours, sharper resolution, pixel for pixel than any conventional image sensor without the need for interpolation.

Conventional image sensors feature just a single layer of pixel sensors in a tiled mosaic pattern. Each pixel detects only one colour of light, which has been filtered through a single red or green or blue colour filter. As a result, two thirds of the colour information at each pixel is blocked out. Therefore to compensate for this, colour interpolation is used. Unfortunately, this leads to colour errors, colour artifacts and loss of image detail.

It will be really interesting to see the new specification of the SD14 and whether the new sensor can improve on the poor night performance mentioned in reviews of the SD10.