Bob, There is no issue in paying attention to terms like AFov especially when it is an actual value that accounts for the distortion profile. Beyond that just make sure it's an apples to apples comparison and she'll be, well .... apples ! , and Bob's your uncle ! :-O
'Real' 'AFov' as listed by Allbinos is the product of the measured Magnification × 'measured' RFov. Allbino's measures this real field of view at somewhere from 6-15m (and either scales, or calculates using a narrow angle approximation from there) according to their test protocols, but obviously 1000m would give the least margin of error due to measurement.
Regardless of that, your post#82 is still a bowl of fruit salad ! :eat: since based on your mixed convention AFov's you have the EDG and the MHG *rs* about (compared to the real world experience - or what it will be, the accuracy of Nikon's mail notwithstanding
It is very important to use the same AFov conventions and compare apples with apples. The ISO convention gives lower numerical values, but has 'much' wider real fields of view than that would indicate.
The MHG will have 'much' wider RFov's than the EDG ........ as you yourself said, (somewhat in contradiction to your conclusions you posted from the AFov's).
Henry, according to the Allbino's test protocols, they get the measured Magnification power by the ratio of the measured objective diameter divided by the measured exit pupil diameter. As mentioned, they measure the Real Field of View at a distance of somewhere between 6m and 15m. Allbino's doesn't explicitly specify, but I would think? they would apply the small angle approximation to the measured distance to get the angle they quote. They then multiply these two 'measured' values to get the AFov figure they quote. Obviously this is not 'entirely' 'perfect'. :cat:
Could you please elaborate for us on the
"couple of accurate home hobbyist methods" you mentioned? Thanks. :t:
PS. Don't be so 'down' on the 'Rabbit Hole', fable has it, that it can lead to 'Wonderful' things! 3
Chosun :gh: