Tracking accuray depends on the alignment accuracy and inherent tolerances such as mechanical play, however, star Polaris), Polarie tracks the sky to minimize the effect of This is the absolute minimum configuration which should not exceed a payload of 3 kilograms (7 lb).Īfter pointing to or near the celestial pole (e.g. It attaches to a standard tripod and accepts a ballhead onto which a camera is mounted. The Vixen "Polarie" is a compact, highly portable equatorial tracking mount for wide angle nightscape andĬonstellation photography. The original images are 1.5° wide, but sacrificed both a little width and height during stacking. The following samples have been produced with a Nikon D5300 in the prime focus of a Vixen A80Mf Ø80mm, 910mm, f11.4 refractorĪnd stacked using "DeepSky Stacker" software with trimming in Photoshop 9. To be stacked in software, in that you may not wish to spend a lot for a motorized mount. High tracking precision is not required if you take several images, say, under one minute exposure While tracking is not required for a good shot of the bright moon, all other objects will need to be Wide field objects, such as the Rosette or North America nebulas require a shorter focal length, say 400mm (3.4°) to 600mm (2.2°) This is quite right for popular deepsky objects, such as the Orion NebulaĪnd the half degree wide Earth moon. In comparison, say, a 300mm f6.3 telephoto lens has a clear aperture of 48mm,Ī standard mirror lens 500mm f8 sports 62mm, but is obstructed by its secondary mirror.Ī scope with a focal length of, say, 1000mm will yield a FOV of 2.1° on a full frame sensor or 1.3° on an APS-C sensor. Thus collecting more light and contrast at a higher optical resolution. Since the adapter is threaded you can use your eyepiece filters, such as skyglow and IR blockers. For astrophotography autofocus and other CPU controlsĪre not required anyway in that a low cost (used) telescope and a simple DSLR T-ring adapter (pictured) is a true alternative. Lenses with a focal length of over 300 millimeters tend to be expensive. With a Telescope The Moon - Nebulae - Galaxies Objects on or near the celestial equator (declination = 0°) draw the longest trails. ISO6400 should not be exceeded (ISO800 <= 1.4, ISO1600 <= 2.0, ISO2000 <= 2.8, else ISO3200 or 6400).Īllowable exposure times until stars trail depend on the focal length of the lens, sensor size and object declination. Required ISO values depend on exposure time and sky glow in that desired results are best obtained by tests, while When shooting in intervals for stacking, time lapse movies or saving images in RAW format,īoth noise reduction functions should be disengaged. High-ISO Noise Reduction: Try with "Low" or "Normal". Hence, a noise reduced image takes a bit over twice Only which is subtracted from the exposure and so saved. Long-Exposure Noise Reduction: after an exposure the camera takes another image using the same parameters but
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