Does barlowing change the AFOV?

[WayBig]

...or to give an example, if I 2x barlow my 60degree 16mm eyepiece, should I get the equivalent of an 8mm 60degree eyepiece?

and if so, is there any limit, would it still hold true for 82 or 100 degree eyepieces?

does a powermate behave the same way?

Thanks

[John]

Generally the answer is no, the AFoV remains unchanged. I say generally because there are some eyepiece / barlow combinations where the barlow vignettes the FoV of the eyepiece - so you loose a bit at the edges. If you use a 2" barlow with 1.25" eyepieces there is no chance of this of course.

I use a 2" 1.6x Antares barlow with my 8mm and 6mm Ethe and get 5mm and 3.75mm with a 100 degree FoV - it's a superb combination IMHO