A New Addition to the Eyepiece Stable

When I purchased the GT-81 refractor in 2011 the retailer suggested and provided two Vixen NLV eyepieces; a 20mm and 6mm. A Celestron 2x Barlow lens was thrown also into deal. Being short sighted I wear spectacles so eye relief is an important consideration when selecting eyepieces.  The 20mm of eye relief the Vixens provide is sufficient for me to observe comfortably wearing glasses.

Normally I use the 20mm eyepiece, having the lower ( x24) magnification for observing those deep sky objects (DSO) I'm interested in, particularly star clusters. For binary star observations I start at low magnification then swap to the 6mm (x80) for splitting multiples with small separations.

Whenever I wish to engage in planetary work I make use the 6mm and the Barlow to observe and recently have enjoyed seeing Jupiter's Galilean moons displayed through Central London's skies and during occasional brief periods of good seeing observing transits and the GRS on Jove.

For lunar viewing I screw in a variable polarising filter into the thread of the 6mm and pop it into the x2 Barlow for excellent views of the Moon - I have a current fondness for the various features of Mare Imbrium.

This month (2013 Feb) I've decided to plug a gap in my eyepiece range and add one with a wider field of view than the 45 deg of the 6mm and the 50 deg of the 20mm Vixens. Researching suitable eyepieces with sufficient eye-relief I was attracted to the TeleVue range and in particular the 17 mm ER offered by the Nagler4 12mm.

I took one on trial from my local supplier, Widescreen Centre, to put it through its paces. It’s a bit of a beast: approx three times as heavy as my little Vixens and stands much taller on the GT-81. Initial concerns whether my 'scope or my grab'n'go mount I use in Central London, the light but sturdy Skywatcher AZ4, couldn't take the EP's weight were allayed quickly. Viewing the waning gibbous Moon on the first trial night provided the best lunar experience I've ever had. Tiny craters and rilles, slightly difficult to discern with the Vixen, shot out at me with pin-sharp clarity. The field of view of course is immense with no apparent fall off at the edge in sharpness of the star field surrounding the Moon.

I will be keeping the Nagler and look forward to using it on a regular basis.