TeleVue Optics offers two of the finest short focal length zoom eyepieces available today. TeleVue Nagler zoom eyepieces introduce a new era in high power observing with short focal length telescopes. The short focal length eyepieces needed to produce high magnification with these telescopes were notoriously uncomfortable to use. Both Nagler zoom eyepieces offer a comfortable 10mm eye relief while maintaining a constant focus and 50 degree apparent field.
Zoom eyepieces have been embraced by spotting scope users for their quick power change convenience. Zoom eyepieces represent an interesting option for planetary observing, allowing the user to dial-in the maximum magnification that the seeing conditions will permit at any given time. The ability to fine tune the exit pupil to obtain the best overall object contrast is an overlooked advantage, especially when using nebular filters.