Jump to content




EP's eye relief question


Recommended Posts

I wonder when you see the E.R. figure for an EP like 15mm, 20mm etc if that's the distance that you will still be able to see the _whole_ field the EP provides, right out to the barrel circle sides.

I've never seen into Naglers or anything > 68fov. Do those who own those megawide view EPs see right out to the circle edge with their eye at the spec relief position?

For my own EPs that supposedly have between 10-20mm relief, I cannot see to the edge, I have to almost do the "eyelash graze" to see the edge.

Of course, the object I'm interested in isn't at the edge and like most, maybe lower price stuff there is some aberration at the outer.

Link to comment
Share on other sites

The quoted eyerelief is the maximum distance your eye can be from the eyepiece

and still see all of the field of view, right out to the field stop.

Sometimes the eye relief is measured from the glass, sometimes from the metal or

rubber upper end of the eyepiece.

10mm or 12mm ER is quite tight, and if you wear specs, you may not see all of the

fov, 15mm or more is much nicer. But as with all things, what bothers some, may

not be an issue with another. It does bother me, and I use a 27mm Panoptic (19mm

ER) and Radians & Vixen LVs, all 20mm ER, even though I don't wear glasses to

observe. I can easily see out to the field stop with all these eyepieces.

Regards, Ed.

Edited by NGC 1502
Link to comment
Share on other sites

If I get my eye in the right position I can just about see the edges of all of the field of view of my Nagler and Ethe eyepieces. But really the intention with these eyepiece designs, I feel, is that you get the impression of looking into a "pool" of space without an apparent limit at the edges. Personally, I like that :)

I appreciate though that some people don't like that approach and there are a wide variety of fields of view to suit all tastes :(

Edited by John
Link to comment
Share on other sites

Just back from some skiing and skies are clear so while gear settles I'm checking in. :)

Alright then. I know it's not going to be accurately determined but a rough guide is the little finger which is around 15mm and for sure that's still a distance I won't see the "corners" in mine and need to get closer. I suspect with the giant Naglers which appear to have a larger bit of glass at the viewing end anyway, that one will still get the "pool or spacey" effect.

I don't use spectacles though I need to have them for the charts but I was curious about how much the given spec meant.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.