1.25" or 2"?

[04Stefan07 (Stefan)]

My scope can take both the 1.25" and 2" eyepieces.

I have never used a 2". Can someone tell me the difference and if it's worth spending more of them?

Thanks.

[mswhin63 (Malcolm)]

I had trouble initially so instead of fighting it I purchased Baader Planetarium lenses which can work both 1.25 and 2".

If I didn't decide to go into Astro Photography I would have set my lenses to 2" and run it that way. Instead I use them in 1.25" inch mode especially when do planetary imaging. I only use the eyepieces sparingly now possibly for sharing observations or very quick set-ups.

[ZeroID (Brent)]

As far as I understand it for short focal length larger scopes a 2" EP is better as it allows the wider angle light rays to not be vignetted at the EP focusser entry.
For higher f# smaller scopes there appears to be no advantage.

I bought a 32mm 2" Kellner for my 10" F5 cheap on sale to see if it made any difference to viewing. Other than being a nice wide view lens and a lot heavier it was no better visually than my 20mm GSO Superview EP.
The real advantage with 2" IMHO is being able to attach the DSLR via a T Mount adapter to take pix.

Your mileage may vary of course ..

[TrevorW]

A 2" wide field of view has no comparison

I've got both but I'd probaly go 2" for the 15-40mm range and 1.25 for the 5-10 range

personally I'd only ever have 5 eyepieces

5mm 10mm 15mm 30mm 40mm