Ep's millimeters

[leenewtoastro]

a Ep's "size in mm" is the diameter or it visually looks like it is?.

but is there any change in its thickness or shape?

i ask because i don't see why you would get more magnification if it was the exact same piece of glass/lens/angles but just smaller

[johninderby]

The "mm" refers to the focal length and hence magnification factor of the eyepiece. It has nothing really to do with the physical size of the eyepiece.

John

[yeti monster]

^^^hence the enormousness of a 5mm Hyperion!

[Moonshane]

As John says. e.g. compare the 3.7mm Ethos with a 25mm Plossl.

[johninderby]

As John says. e.g. compare the 3.7mm Ethos with a 25mm Plossl.

I'll go grab my camera and take a relevant pic.

John

[Moonshane]

he took the bait!!

[leenewtoastro]

hmm of course the distance changes too. so is the diameter important?

i must be to do with lens angles / shape that dictates the diameter

[johninderby]

he took the bait!!

"Hook line and sinker" :D

John

[Moonshane]

cheers John

amazing eyepiece. the 3.7mm Ethos isn't bad either

[NGC 1502]

cheers John

amazing eyepiece. the 3.7mm Ethos isn't bad either