## Re: Can someone do some TFOV math for me?

The formula for maximum FOV of a refractor is

1 Radian (57.3) multiplied by 27mm or 46mm (clear aperture of a 1.25" or 2" diagonal) divided by the focal length of the scope.

So for example, my 150mm f/8 refractor with a focal length of 1200mm and a 2" diagonal

57.3 x 46 / 1200 = 2.19° FOV

*Refractors:* Antares 105 f/15, Celestron 150 f/8, Stellarvue NHNG 80 f/6.9, TAL 100RS f/10, TS 102 f/11, UR 70 f/10, Vixen SD115s f/7.7

*Mounts:* Celestron SLT w/ pier mod & EQ-3 tripod, Celestron hypertuned CG-5 w/ tracking motor & Argo Navis, Manfrotto 028B w/ Stellarvue M2C, Manfrotto 055PRO w/ 128RC, TAL-1 HD EQ, Vixen SXP w/ HAL-130 SXG & half pier

*Diagonals:* 2" Astro-Physics MaxBright, 2" Zeiss/ Baader prism, 2" Baader Herschel Wedge (Photo Version), 2"

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Amici prism, 2" Stellarvue Dielectric, 2" TeleVue Everbrite

*Eyepieces:* A-Z

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*The weakest link in the optical chain is the large nut located directly behind the eyepiece/ camera. - Gabrielle*

*Ya gotta keep this Apo/*

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thing in some balance of perspective. Apos are awesome, but long focus Achros aren't that far behind them - Siriusandthepup (CN)

*Refractors kick arse precisely because they don't hide behind excuses. That is, they have no obstructions to hide behind. - Jon Isaacs (CN)*