Quote:
Originally Posted by Steffen
How so? According to the tech specs their field stop diameters and the resulting TFOVs and magnifications on a 1500mm focal length scope are:
TV Plössl 32 - 27mm - 50.4' - 68x
TV Radian 18 - 18.3mm - 43' - 83x
TV Nagler 11 - 14.9mm - 34' - 136x
Cheers
Steffen.
|
I didn't use the field stop in my calcs for TFOV. Generally i just use AFOV / magnification. The mag for the 32 is only 46x
The televue website advocates the use of the formula you used and just about every other site i've found uses the AFOV/mag. Backyard Astronomers Guide lists both but states the AFOV/mag is generally ok as Televue are about the only company that releases field stop. Will have to do some more reading on this. Thanks Steffen.