The Sky-Watcher Esprit line of high-quality ED Triplet APO refractors will perform flawlessly whether you enjoy it as a visual instrument or use it as a giant lens to image the Universe with one of today's amazing CCD cameras. The designers of this telescope line concentrated on the desires and requirements of the avid astro-imager, from a three-element apochromatic objective with included thread-on field flattener to the beefy oversized micro-focuser. The air-spaced ED APO optics are fully multi-coated for extra clarity, contrast, and protection, and the two-element corrector, which comes standard with the Sky-Watcher Esprit, will ensure a flat field across the entire focal plane. This system produces a 43mm image circle, and you have about 100mm of back focus for plenty of imaging accessories. The dew shield, when extended, will protect the optics from dew and help increase contrast by blocking stray light that might otherwise strike the glass. However, the shield is fully retractable when necessary in order to shorten your OTA for storage and travel The Helinear Track Focusing System, a Sky-Watcher exclusive, is a rock-solid 3.4" rack & pinion focuser that will perform smoothly, without image shift, due to the extra support rail on the top of the drawtube. The micro focuser allows you to make course and fine adjustments to focus, and the knobs are easy to turn, even with cold hands or with gloves on. A thread-on step down ring takes the opening down for 2" accessories, and a 2" to 1.25" adapter is included in the package. Accessories are a big part of any telescope system, and Sky-Watcher wants to make sure that you start out right. Included with every Esprit refractor is a 2" dielectric diagonal, a 9 x 50 RA erect-image finderscope and bracket, a Canon camera adapter, tube rings with a CGE ("D" style) dovetail bar, and an aluminum foam-lined case.