Image of the day

From the
ATWB Customer Gallery

Comet Neowise setting over Mt. Princeton, July 18

My Account

New to Astromart?

Register an account...

Need Help?

Max TFOV with BV?

Started by williamichang, 08/15/2003 08:34PM
Posted 08/15/2003 08:34PM Opening Post
Does a (1.25") binoviewer limit the maximum _true_ FOV, in addition to the EP fieldstop? For example, the 35mm Ultima cheats by not having a fieldstop, and is definitely wider than the 30mm. Do I get to keep that extra bit of FOV in a Denkmeier II (or another BV) or lose it anyway, to the 27mm clear aperture of the Denk? Thanks, -- William
Posted 08/16/2003 12:12AM #1
The "glass path" through a typical binocular viewer is between 5 and 5.5 inches. Imagine having a 5-inch barrel on your 30mm or 35mm Ultima... Sounds pretty "narrow," doesn't it?

However -- binocular viewers with 27mm entrance apertures *can* accomodate scopes as fast as ~f/6ish *without* restricting aperture and true field of view.

Best wishes.