The ATIK 4000 Monochrome incorporates a 4 megapixel Kodak sensor with 7.4um pixels, which provides an ideal introduction to the joys of large-format imaging, being much bigger than the Sony sensors which are typically used for astronomy. At 15mmx15mm, the sensor array is a perfect fit for standard 1.25" filters, offering a considerable saving over the 2" filters required by anything larger. Resolution from the ATIK 4000 is fine enough for printing at A4 or even A3 size, and when viewing images on a computer monitor it is a pleasure to see details emerging at ever-deeper zoom levels.
While the other cameras in the ATIK range use Sony sensors, the large-format cameras incorporate Kodak devices. These have gained a great reputation in astrophotography and offer qualities not available in the Sony CCDs. However, optimum performance from the Kodak chips is only obtained with the use of highly sophisticated control electronics and advanced cooling systems, and this is where ATIK's expertise in design and build comes to the fore. The Kodak sensors require dark frames to be used for calibration, and these must be taken at the same temperature as the primary image.
The ATIK 4000 achieves this through the provision of full, set-point, temperature regulation using a two-stage Peltier element and fan. This can provide cooling to 40 degrees below ambient and will be suitable for the majority of conditions. For more demanding use, water can be pumped though the camera's internal heat exchanger. When water cooling is employed, the maximum amount of cooling depends on the water temperature, with approximately 45 degrees of cooling being available using water from a typical cold tap. Such efficient cooling cuts thermal noise to an absolute minimum and reduces the prevalence of hot pixels, but it raises the risk of condensation forming in or on the camera.
A high-efficiency desiccant is used to dry the air inside the sensor chamber, preventing internal condensation, while condensation on the outside of the camera is avoided with the use of heater elements which gently warm the window. The power supplied to this heater is controllable through software so that it can be adapted to the environmental conditions. The ATIK large-format cameras have been designed and built to fulfill the needs of the most demanding users, whilst offering an unparalleled simplicity of use. The cameras have only two sockets - a 2.1mm socket for the 12V power supply and a USB2 port for communicating with the computer - and they are compatible with the highly acclaimed Capture software as well as AstroArt, CCDSoft and MaximDL.