The official spotting scope of the U.S. Army's XM110 Semi-Automatic Sniper System (SASS). The Multicoat 4® lens system optimizes light transmission for peak brightness, resolution, and contrast, even at the highest magnification settings. Folded light path technology provides powerful magnification in a lightweight, compact design (just 12.4" long and 37 oz). The Front Focal reticle magnifies the reticle along with the image, so you can estimate range at any power setting using the Mil Dot or Tactical Milling Reticle. The universal, ¼-20 thread tripod attachment is standard. Digital camera compatible, it makes capturing images easy. The McCann Rail accessory allows you to adapt your spotting scope for night-vision and other accessories. Accessories for the Mark 4 spotting scope give you powerful, performance enhancements for a variety of tactical situations and weather conditions. Includes a protective, soft-side case that remains on the spotting scope during viewing for maximum utility. Incredibly rugged and absolutely waterproof.
- Actual magnification: 12.7x to 38.1x
- Linear field of view: 168 to 52 feet per 1000 yards/56 to 18 meters per 1000 meters
- Angular field of view: 3.2 to 1.0 degrees
- Objective aperture: 60mm
- Twilight factor: 26.8 to 48.9
- Exit pupil: 4.8 to 1.5mm
- Eye relief: 30 to 30mm
- Close focus distance: 36 feet/11 meters
- Weight: 37 ounces
- Length: 12.4 inches
Light reflecting off lens surfaces diminishes image quality. So Leupold engineers developed Multicoat 4, our own proprietary lens coating system to keep image quality pristine. Multicoat 4 greatly increases the amount of all available light that reaches your eye, while at the same time, it minimizes the reflections of the sky on the outer eyepiece. You'll never be able to control the light, but with Leupold's Multicoat 4, you can always make the most of it.
What is Twilight Factor?
The factor that has the greatest impact on resolution or image detail, will be dependent upon the amount of light available during the time of observation. During daylight hours, when your eye pupil size will be only about 2 to 3mm, magnification will be the principal factor in image resolution. At night, with the eye pupil dilated to 6 to 8mm, aperture size is the controlling factor. In twilight conditions both of these factors control resolution effectiveness and the twilight factor is the term that compares binocular performance under these conditions.
The twilight factor is calculated by taking the square root of the product of the magnification and the aperture. The higher the twilight factor, the better the resolution of the binocular when observing under dim light conditions. For example, a 10 X 40 (twilight factor 20) would effectively resolve better under these conditions than a 7 X 35 (twilight factor 15.4) even though the 10 X 40 has a smaller exit pupil. Remember, however, that the twilight factor does not take into account the transmittance or quality of the optical system.
Leupold Mark 4 Spotting Scope, 12-40X60, Mil Dot Reticle, Black Matt Finish 53756