Quick question about eye-relief

[Jasonb]

Hi all,

So, if I'm right, eye-relief effectively means how far away your eye should be from the eyepiece to see through it perfectly? I've seen some reviews/comments on Eye Relief along the lines that if it has 'good eye-relief' (let's say 16mm or something) then it's handy for people who wear glasses, as I'm guessing that means they can have the glasses on and still see through the eyepiece correctly. This interests me as I've only recently started wearing glasses.

However, what I'm curious about is what's the eye relief on the stock eyepieces I got with my scope? Is there any way I can find this out, or are they too generic to know? 

The two eyepieces I have came with my Skywatcher StarQuest 130P and are labelled Super 25 Wide Angle Long Eye Relief and Super 10 Long Eye Relief.

Thanks in advance!

[Zermelo]

Hi Jason,

I have it that the 10mm has 9.1mm relief and the 25mm has 21.8mm

[Jasonb]

1 minute ago, Zermelo said:

Hi Jason,

I have it that the 10mm has 9.1mm relief and the 25mm has 21.8mm

Great, thanks! Will have to check them out the next time, so far I haven't tried wearing my glasses while using the scope...

[Zermelo]

I can't remember where I found those, I just have them in my own spreadsheet because I have the same eyepieces.
I suspect they are the manufacturer's official figures. Sometimes these are not quite accurate, but they will be close enough.

[Jasonb]

Definitely gives me something to go on Zermelo, thanks! While I think of it, would you know their FOV as well?

[Zermelo]

The 10mm is 52 degrees, the 25mm is 50 degrees (again, probably manufacturers figures)

[Jasonb]

Great, thanks a lot Zermelo, good to have those figures!

[KP82]

The eye-relief is measured from the top surface of the eye lens. So if that piece of glass is recessed in the housing of the eyepiece, the actual useable eye-relief will be much less than quoted by the manufacturer.