Photographic attachment - need data

[ranjan_pendharkar2]

I have recently got a Nikon fieldscope ED III A with a Nikon 20 - 45x

eyepiece. I am thinking of getting the photographic attachment which can be

hooked up to the ED III A making it a 800mm f12.8 lens. What I want to know -

A) which magnification setting of the eyepiece (20 - 45x) has the same field

of view as the 800mm lens, which I get when I couple the ED III A & the

photographic attachment?

B) I will use my F90x with the combo. I suppose I have to set it to aperture

priority or is it manual only?

Thanks for replying...........

[todd peach seattle, washi]

Speaking in general terms, if it's an 800mm lens, the magnification will be about 16x on your F90x (800/50).