Working out the FoV of an eyepiece....

[John]

Could some kind person remind me of the formula to use to work ot the aparrant field of view of an eyepiece from the focal length and the field stop size.

If it was clear I could try the drift method, but ....

Thanks,

John

[Chubster]

This might help.....cant remember if what you want is in there or not, click on the link in the first post

http://stargazerslounge.co.uk/index.php?topic=4475.0

[GazOC]

FOV = eyepiece field stop/telescope focal length x 57.3° is the exact formula

FOV = eyepiece AFOV/ (focal length of scope/ focal length of eyepiece) is a very good approximation.

[John]

Thanks folks - that'll do the trick

John