Well, I am afraid that the definition of the apparent field of view is as I stated. There is no "Real Field of View", or "effective apparent field of view", as those are artificial concepts used to attempt to make the old formula for true field appear to be more accurate than it actually is. The only "real" fields are the actual angles measured for the angular span that the eye sees in the eyepiece (the Apparent Field of View), or that the observer measures on the actual "real" sky (the True Field of View). One should either use the old formula and accept its "ballpark" results, use the field stop formula, or just go ahead and measure the true field of view in a telescope and forget about formulae altogether. Clear skies to you.