Browse by Manufacturers

More Information  · Recommended Accessories Price $112.00 $118.00 SAVE: $6.00 (5%) List Price $150.00 Field of view 43° Eye Relief 23mm Focal Length 40mm Number of optical elements 4 Barrel Size 1.25" Weight 8 oz Warranty 5 years Telescope Eyepiece Formula To calculate the magnification and approximate actual field of view of this eyepiece on your telescope, enter the focal length of your telescope below and press the "Calculate" button. mm

It provides a huge 8.9mm exit pupil with an f/4.5 Dobsonian reflector. As the eyes of most observers are unable to dilate to this size, this eyepiece will probably waste a good portion of the light-gathering capacity of a fast focal ratio scope. It is better suited to the longer focal ratios of refractors, Schmidt-Cassegrains, and Maksutov-Cassegrains than it is to reflectors with focal ratios shorter than f/6.

At f/6 and above, it would be an excellent choice to give you the widest and brightest field possible from a 1.25" focuser telescope. The very long eye relief makes it a good choice for those who wear eyeglasses.