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If this is covered already, please mention the thread. I'm reading my way around this, but my search-fu is sometimes weak...
I am wondering how to derive the maximum usable field of view available from any specified scope, based on (1), the scope's type of design, and (2). focal length, and all figured on the best eyepiece choice for that goal?
For a given magnification, does the eyepiece's "wide field" or "wide angle" capability change it or only determine how much you can see at once with normal eye relief?
If this seems a silly Q., just remember this is after all the "Beginners' Forum".
57.3 x Field Stop / focal length will give you the maximum FOV of the telescope is use the diagonal size as the field stop.
My 150mm x 1200mm refractor with a 1.25" diagonal (27mm clear aperture) would be 1.289°, with a 2" diagonal (48mm clear aperture) would be 2.29° SCT and Maks are a bit different as they have a baffle tube inside so that will determine the maximum clear aperture of the system.
A 1.25"diagonal in one will not vignette but a 2" using a eyepiece such as a 35mm 68°AFOV may a bit.
57.3 x 27mm / 1200 = 1.289°
Gabrielle See Far Sticks: Elita 103/1575, AOM FLT 105/1000, Bresser 127/1200 BV, Nočný stopár 152/1200, Vyrobené doma 70/700, Stellarvue NHNG DX 80/552, TAL RS 100/1000, Vixen SD115s/885 EQ: TAL MT-1, Vixen SXP, SXP2, AXJ, AXD Az/Alt: AYO Digi II, Stellarvue M2C, Argo Navis encoders on both Tripods: Berlebach Planet (2), Uni 28 Astro, Report 372, TAL factory maple, Vixen ASG-CB90, Vixen AXD-TR102 Diagonals: Astro-Physics, Baader Amici, Baader Herschel, iStar Blue, Stellarvue DX, Tak prism, TAL, Vixen Eyepieces: Antares to Zeiss (1011110) The only culture I have is from yogurt
In case I have completely misunderstood your question (likely )
Take a look at this calculator, enter your telescope and eyepiece information and it will show how AFOV, TFOV, Exit Pupil change: http://www.stargazing.net/naa/scopemath.htm
Gabrielle See Far Sticks: Elita 103/1575, AOM FLT 105/1000, Bresser 127/1200 BV, Nočný stopár 152/1200, Vyrobené doma 70/700, Stellarvue NHNG DX 80/552, TAL RS 100/1000, Vixen SD115s/885 EQ: TAL MT-1, Vixen SXP, SXP2, AXJ, AXD Az/Alt: AYO Digi II, Stellarvue M2C, Argo Navis encoders on both Tripods: Berlebach Planet (2), Uni 28 Astro, Report 372, TAL factory maple, Vixen ASG-CB90, Vixen AXD-TR102 Diagonals: Astro-Physics, Baader Amici, Baader Herschel, iStar Blue, Stellarvue DX, Tak prism, TAL, Vixen Eyepieces: Antares to Zeiss (1011110) The only culture I have is from yogurt
M'Lady Fraktor and Refractordude, these two calculators are now going to be permanently in my toolbox.
Between the two of those and some trial and error, I think I can nail down the max angles for my three scopes. I had not thought about the 'reducer', (opposite of Barlow's increase of focal length), concept, but it might hasten one's arrival at too wide of an eyepiece??? I told you I am new to most of this!!!
Yes, I was thinking of the purely physical characteristics of the telescope, including that mirror in the middle effect, any built in non-removable shade's impact, and AnyThing else that would be a factor in finding out the arc of, "As wide as it gets".
I can foresee times when a tighter view will not be the prize.
