Re: [William Optics] Re: 2 inch optics
- It should be also mentioned that to avoid vignetting in a 32mm Plossl 1.25 inch eyepiece one needs a 2-inch diagonal. This is because the light path widens as it gets closer to the objective. The faster the scope the more difference this makes.Scott Walker----- Original Message -----From: GregSent: Saturday, June 30, 2007 10:46 AMSubject: [William Optics] Re: 2 inch optics
The reason for going to 2 inch optics is to increase the true field of
view available. A good example of this are the typical 32 mm and 40 mm
Plossl. Both are 1.25 inch eyepieces but the 32 mm has a 50 degree
apparent filed of view while the 40 mm has a 42 degree apparent field
of view. Both have the same true field of view because the 1.25 inch
light path is limiting it. Any wider true field requires a 2 inch
light path. With a 2 inch light path the true field limit it reached
by eye pieces like the 31 mm Nagler and 41 mm Panoptic.
--- In William-Optics@ yahoogroups. com, "keepers80" <jlutkin@... > wrote:
> As an amateur new to the game could I pose a question?
> "2 inch diagonals and eyepieces are over weight, over priced, over
> hyped and provide no overall advantage over 1.25 inch optics for
> either visual or photographic purposes"? Please discuss.