CDC eyepiece specs

I am trying to insert some specs for my equipment in CDC, so as to
simulate EP circles.

Ok, CDC says, for each EP, enter FOVx60', so for my 11x80 (says: "Field
4.5^o"), should be: 270', which is pretty close to what I see.

For the 20x100, the binocs simply say "Field 4.9" (no degrees or
anything such), so here I am stumped: The result certainly can't be 294'
(can it?), since such a circle on CDC is larger than the circle for the
11x80, and the later have lower magnification.

What's the deal here?

Also, how can I calculate the FOV for my zoom EP for my Tasco 60mm/700mm
f.l.? The EP specs don't say anything about its apparent field, only its
focal length: 22-7.4mm.

Thanks much in advance,
--
I. N. Galidakis
http://users.forthnet.gr/ath/jgal/
------------------------------------------
Eventually, _everything_ is understandable

A 4.9 degree field would be unusual for 20x100, I think a 3 degree field is
more likely. There are some of these marketed as 4.9 but its not true.
You'll have to do some field tests. A quick check is how many moons will
line up across the view (.5 degrees each).

As far as the zoom goes, best guess is around 40 degrees at 22mm to around
55-60 degrees at 7.4. These are estimates of the apparent field of view
which you'd have to convert to actual fov by dividing by the magnification
in your scope. Somebody might have the numbers.

Good luck,
Ed T.


"Ioannis" wrote in message
news:1092784059.458348@athnrd02...
I am trying to insert some specs for my equipment in CDC, so as to
simulate EP circles.

Ok, CDC says, for each EP, enter FOVx60', so for my 11x80 (says: "Field
4.5^o"), should be: 270', which is pretty close to what I see.

For the 20x100, the binocs simply say "Field 4.9" (no degrees or
anything such), so here I am stumped: The result certainly can't be 294'
(can it?), since such a circle on CDC is larger than the circle for the
11x80, and the later have lower magnification.

What's the deal here?

Also, how can I calculate the FOV for my zoom EP for my Tasco 60mm/700mm
f.l.? The EP specs don't say anything about its apparent field, only its
focal length: 22-7.4mm.

Thanks much in advance,
--
I. N. Galidakis
http://users.forthnet.gr/ath/jgal/
------------------------------------------
Eventually, _everything_ is understandable