another eyepiece question

[mojolomjl]

Thanks to all who replied to my question about long eye relief EPs, but I now have another question which I hope doesn't sound too daft. I called in at a small telescope shop in Liverpool today to ask about LREPs and he suggested that my EPs should have an eyecup which you can attach to the EP, as without one you have no eye relief at all as the lens is almost flush to the rim.

Any advice would be greatly appreciated.

Maurice.

[thing]

My advice would be not to go there again. Eye relief is eye relief, it has nothing to do with rubber eyecups.

[philf]

I thought rubber eye cups were to stop stray light entering from the side ... not to do with eye relief at all

[Astro_Baby]

They kind of vaguely control eye relief on some EPs where the rubber cup screws out - in the sense that with the rubber cup screwed out you cant put your eyeball too close BUT eye relief is in the optics not in the rubber cup which is there to keep out stray light - at least as far as I know.

[GazOC]

The eye-relief is in the optics, the rubber cups are there for stray light, comfort and can be used as a guide where to place the eye. They don't govern the eye relief of the eyepiece.

[Astro_Baby]

Thats what I meant Gaz - you said it better