Eye relief

[Daz Type-R]

Can somebody explain this in laymens terms?

Is it how far your eye has to be away from the ep in order to get the maximum ammount of fov from the ep?

Or is that utter rubbish and it's just how long you can keep looking through the ep before you get eye ache?

Regards,

Darren.

[John]

...Is it how far your eye has to be away from the ep in order to get the maximum ammount of fov from the ep?....

Thats more or less it Darren

Eye relief is measured in mm from the top of the eye (top) lens of the eyepiece. It's the point at which your eye needs to be to be able to see the full field of view that the eyepiece is giving.

[NGC 1502]

Is it how far your eye has to be away from the ep in order to get the maximum ammount of fov from the ep

Hi Darren, yes thats correct. If your eye is too far from the eyepiece, you won't see the whole of the field of view.

if you wear specs to observe, long eye relief is especially welcome,

but is a nice feature for everyone.

Regards, Ed.

Edit : John beat me to it

[Mikea]

I think you have got it right (the first answer!). Normally only an issue if you need to wear specs for viewing like me

[Daz Type-R]

Thanks for that.

I wear glasses, do most people take their glasses off and adjust the viewer to componsate, or do you leave them on but when buying ep's make sure you get one with good eye relief?

Am I right in thinking that plossals give good eye relief but only down to about 6mm?

Should I be looking at any other type of ep?

[Daz Type-R]

Doh, just seen everybodys reply above.

Cheers.

[John]

....Am I right in thinking that plossals give good eye relief but only down to about 6mm?

Should I be looking at any other type of ep?

Plossls are not good for eye relief to be honest. The TMB Planetary eyepieces are a bit better than plossls optically and provide significantly more ER in all focal lengths.