1.25" or 2" diagonal?

[AndyH]

Sorry about that Paul. Should've mentioned that sooner

Mind you, you can still get wide field ep's in 1.25" under 25mm. The widest lowest power 'piece would be a 32mm 52 degree plossl in the smaller size. Still should give a decently wide view.

Cheers,

Andy.

[John]

The thing (piece) i need to convert my 1.25" EPs so they work as 2" EPs (have a wider FOV).

Can it be done or do i have things backwards?,and only 2" EP can be reduced to being 1.25" EPs?.

You can't really do it that way unfortunately. The manufacturers utilise the 2" barrel to enable a larger field of view but there is more to it than that.

The part of the eyepiece that defines the edges of the field of view is called the field stop. It's diameter defines how wide the field of view will be and, obviously, the diameter of the barrel of the eyepiece determines the maximum field stop size - which is why a 32mm 2" eyepiece can be designed to have a larger field of view than a 32mm 1.25" one.

The lenses used in 2" eyepieces tend to be larger diameter to accomodate the wider field of view as well.

A popular approach is to have a scope that will accept 2" and 1.25" eyepieces (through an adaptor) then use the smaller format for medium and high power (where the 2" design has no advantages) and 2" EP's for low power.

Of course you also need 2" filters if you use 2" eyepieces - more £'s as usual !

[LukeSkywatcher]

I have a 32mm Celestron Plossl. It is my absolute favourite EP. It gives me fantastic widefield views. I will never part with it.

Thanks for the advice. Sorry i was so confused and confused the hell out of you all.

[michael.h.f.wilkinson]

Most 2" focusers come with a 1.25" adapters.