…continuedDeep-Sky Imaging with Digital Cameras
Imaging relatively bright deep-sky objects such as globular clusters is a piece of cake for Honis. "In fact, a single 16-second exposure is sometimes acceptable," he says. "For dim clusters, stacking several images can help improve the image. For dimmer galaxies or nebulae, the exposure limit becomes a problem, even with a large aperture. I need to stack multiple exposures to improve the results."
To assist in the camera’s cooling, Honis attached a small computer fan to his C-2000 Z camera. "This involved taking the camera housing apart, removing the tripod-mount socket to create an opening, and mounting a 12-volt DC fan over the opening to force air into the camera body," he explains. "The results are dramatic. Heat generated by the electronics is quickly pumped out of the camera. On freezing nights I can do practically noise-free, single-shot deep-sky imaging with a 2-megapixel $300 point-and-shoot digital camera in full color!"
Bear in mind that modifying your camera will void its warranty, so proceed at your own risk. Failure to take proper precautions can result in permanent damage to the camera’s sensitive electronics and/or optics. "After disassembly and reassembly my camera functioned properly, but your camera may not," warns Honis.
How deep can such an air-cooled camera setup go? "By stacking multiple exposures, the bright galaxies are not a problem," he says, "and I can crudely image very faint objects such as the Horsehead Nebula."