Widest 1.5" eyepiece

[tsh]

Searching in vain for M82 has lead me to think about upgrading the standard 20mm erecting eyepiece (which to be fair seems better than the included 10mm).

Scope is a Celestron astromaster 130-EQ (650 mm, F/5).

From what I've read, it seems that somewhere between 32 and 24mm will give the same field of view (which I guess is why the better EPs move to 2" before 32mm?).

Before I buy a Baader Hyperion 68*, am I missing anything, and would I be as well off buying a cheaper 32mm EP (and maybe a finder scope for the same overall price - or finder scope as well). The ability to fit a T adaptor to the EP is useful, if I can use this with my DSLR. I'm also planning on upgrading the red dot to a Rigel quickfinder at the same time.

[Mr Spock]

A 32mm Plössl will give you x20 and a 2.46° field, a Hyperion 24mm will give you x27 and a 2.51° field. Not much in it so It's down to personal preference.

The higher magnification will give you a darker sky background and allow you to go fainter, but because of the wider field will also increase coma... swings and roundabouts.

If it were me, I'd get a 32mm Plössl. I use a Meade 4000 and it's perfectly sharp but you can get a Revelation for about £27.

[John]

The widest field eyepiece I've ever found in the 1.25" fitting was the Celestron Ultima 35mm (which is the same as the Orion Ultrascopic 35mm) which has an apparent field of view (AFoV) of 49 degrees which would give you 18.6x and 2.63 degree true field of view with your scope. The exit pupil would be 7mm which is on the large side though. It's an out of production eyepiece though so the used market is the only way to get them.

Otherwise Mr Spock's suggestions are spot on.

[Alfian]

Don't forget that a 32mm will give you a 6.4mm exit pupil.  Something like a 25mm Celestron X-Cel LX 60 degree might be better - give you a 2.3 degree fov. and a 5mm exit pupil. The Rigel Quickfinder is a huge improvement over the standard Celestron finder.

[dag123]

Hi Vacuum,

I have this scope and have been able to view M82 quite easily given a dark-enough sky with no clouds.

I use the 32mm EP from the Celestron EP kit to locate both M81 and M82 in the same field of view - no need to use the red-dot-finder, just align the whole scope roughly at the right point in the sky and in the 32mm FOV it is quite easy to locate, especially if you have used the ocular view in Stelarium so you have an idea of what to expect.

If looking at one or the other I'll then switch to the 17mm, although to try and spot the current supernova I have been using the 10mm and 5mm X-Cel EDs, the 10mm probably giving me the most confidence I did actually see it.

Hope this helps

dag123