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Fair enough Raymo. The point I was trying to make is that an EP is not better or worse simply because it is a 2" or 1.25" barrel. What matters are the focal length and apparent FOV, as well as less obvious factors such as sharpness across the field, ellimination of false colours etc.
The barrel diameter is a consequence of the focal length and the FOV, and those are the factors taht should be looked at when considering an EP. For example if I was looking at an EP in the 20mm range and want a high end one. I could look at a 20 or 22mm Nagler or a 21mm Ethos. Both have 2" barrels, but the Ethos has a much bigger field of view for virtually the same power.
In the particular example you mention, the Superview has a 68deg AFOV, which requires a 2" barrel, while a 30mm plossl will only have a 50deg AFOV so a 1.25" is enough, and is also cheaper!
Malcolm
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