Canon USA has released its EOS 20Da digital SLR, designed to address the specific requirements of astrophotography. Its features include a preview LCD and a low-pass filter positioned in front of an 8.2-megapixel CMOS sensor that has been modified to yield sharper and higher-contrast images of various astronomical phenomena, such as diffuse reddish nebulae. The modification increases the transmission of light at the specific wavelength of 656 nanometers, known as the Hydrogen Alpha line, or H wavelength, by a factor of 2.5x.
Live previews have been made possible by locking up the mirror and opening the shutter to display a magnified view of the subject on the 1.8-inch LCD monitor. To help ensure a sharp focus, the central portion of the image can be magnified on the LCD by 5x or 10x. The live-view mode also can be seen on most television monitors while connected to the EOS 20Da camera's video out terminal.
The EOS 20Da incorporates enhanced noise reduction for long exposures and an array of ISO settings from 50 to 3200. Other features include a nine-point autofocus system, full manual controls, up to five frames per second burst mode, and a choice between RAW, JPEG, and RAW+JPEG image recording capabilities.
The EOS 20Da has an estimated selling price of $2,199.