Focal Length: 7mm, 82° field of view
Supplier: Telescope House
Telephone: 01342 837098
The Nagler has a traditional no-frills look about it – it appears that all the research and development has gone into the optics.
With a compact 42mm diameter, it has a fixed, fold-down rubber eye shield.
We found this a little low, and not especially effective at blocking stray light.
In use, it was a bit tricky to find exactly the right position to view from: if your eye is too close your lashes or cheek can interfere with the view, especially when peering round towards the edge of the field.
Eye relief was also too short if you wear spectacles.
In optical tests the Nagler performed very well.
The contrast was impressive, especially between the lunar limb and the background sky. We were also able to resolve some fine detail on the lunar surface.
There was no chromatic aberration visible in the Tele Vue’s field even when we strained to see the very edge, and the eyepiece maintained resolution and separation of the Double-Double’s four stars from field stop to field stop.
It also exhibited a crisp-edged field stop. Colour definition in the double star Albireo was excellent.