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Re: [ATM] Eyepiece in question
Hi Maingot,
On 0, Maingot Fabrice <Fabrice.Maingot@ipcms.u-strasbg.fr> wrote:
> I got an Erfle eyepiece of focal length f=20mm;
> I measured the field stop : d = 18mm.
> The telescope has a focal length F=1103mm.
>
> I compute the angular field of view :
> FOV = 2 atan(d/2F) = 0.93 deg
> so the apparent field of view :
> AFOV = F/f * FOV = 51 deg !!
>
> An Erfle has rather 70 deg of field. Is there
> a problem with my equations, or this eyepiece
> will not suit well with that scope ?
There's nothing wrong with your calculations. To get a 70 degrees fov
you'll need a field stop of 24 mm. So despite this eye piece being an
Erfle, it does have a 51 deg fov.
Clear skies!
Wouter van Reeven
--
Black holes are where God is dividing by zero.
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