Celestron CGX Equatorial 800 HD Telescopes Whitepaper EdgeHD Optics - Page 19

Celestron EdgeHD 1100 Celestron EdgeHD 1100 The 11-inch EdgeHD is optimized to produce its sharpest images in green and red; at these wavelengths it is diffractionlimited over roughly two-thirds of the full 42mm image circle. The relative illumination remains 100% across the central 16mm, then falls slowly to 83% at the very edge of a 42mm image circle. For pictorial images with an APS-C digital SLR camera, flats are unnecessary. For monochrome imaging with an astronomical CCD camera, we always recommend making flat-field images. On nights when the seeing achieves 1.5 arcseconds FWHM, star images shrink to 18µm at the focal plane. On such nights, the EdgeHD 1100 delivers fine images over a 30mm image circle, and well-defined stars over the full 42mm field. The EdgeHD 1100 is a serious telescope. Its long focal length and large image scale give it the ability to capture stunning wide-field images of deep-sky objects with a large-format CCD camera. The Celestron EdgeHD 19