45deg diagonal for frac?

[markse68]

Hi there, just wondering if you find having a 45deg diagonal beneficial in addition to a 90deg one when viewing through a frac? I imagine I could just rotate the 90deg one to get comfortable? I have come to realise a diagonal is pretty much essential either way!

[Stu]

14 minutes ago, markse68 said:

Hi there, just wondering if you find having a 45deg diagonal beneficial in addition to a 90deg one when viewing through a frac? I imagine I could just rotate the 90deg one to get comfortable? I have come to realise a diagonal is pretty much essential either way!

Only time I use a 45 degree is if using the frac as a spotting scope, then it’s a 45 degree erecting prism but I wouldn’t use that for Astro.

90 all the way, I don’t think I’ve ever view ‘Japanese style’ ie straight through with no diagonal, although I guess that would be slightly higher quality, but pretty uncomfortable.

You can turn the diagonal to the side to view, or I often prefer it straight up then sit up high on my observing chair. If you put it to one side with a heavier eyepiece in, make sure it is acting to tighten the barrel up, not undo it. More than once I’ve found my expensive binoviewer and eyepieces hanging upside down having unscrewed the barrel. Fortunately ClickLock fittings mean they didn’t fall out!

[markse68]

Thanks Stu- one less thing to buy 👍 and thanks for the safety tip too!

[johninderby]

I find a 90 degree diagonal is all I need. 45 degree are for spotting scopes.

There is the oddball Televue 60 degree dilectric mirror diagonal ir you really wanted a different angle for nightime observing. 🤔