2" or 1.25" diagonal?

[Donkeiller]

Got a Skywatcher ED 80 on Synscan AZ Goto with Celestron "Eyeopener"

1.25" eyepieces.

I also have 2" and 1.25" diagonals.

I there any observable advantage using the 2" instead of the 1.25" diagonal with this setup?

[milkyjoe]

2" eps give you a wider view of the sky (see my thread 'Star Diagonals') ;-)

[Donkeiller]

Thanks, milkyjoe.

Will the view though 1.25" eps be any better with a 2" diagonal as opposed to a 1.25" diagonal?

[russ]

Thanks, milkyjoe.

Will the view though 1.25" eps be any better with a 2" diagonal as opposed to a 1.25" diagonal?

There is an argument that the 2" diagonal will also benefit 1.25" eyepieces. Which is maybe the case compared to a cheap 1.25" diagonal (a small mirror will probably be the least of your worries with a cheap diagonal). But the quality 1.25" diagonals use a slightly oversized mirror to make sure all light is reaching the eyepiece. So probably no gain at all.

[russ]

Thanks, milkyjoe.

Will the view though 1.25" eps be any better with a 2" diagonal as opposed to a 1.25" diagonal?

There is an argument that the 2" diagonal will also benefit 1.25" eyepieces. Which maybe the case compared to a cheap 1.25" diagonal but the quality 1.25" diagonals use an oversized mirror. So probably no gain at all.

But if you have option or chance to have a 2" diagonal, it makes sense to go that route. At the very least it saves you some hassle down the road should you wish to try some 2" eyepieces.