17 or 21 Ethos

[ENVY]

I have a 12"lightbridge and am off to a dark site in the Flinders Ranges in a few weeks.
I have been saving and would like to get a new eyepiece (ethos) for the trip.
Help required as am not sure which would suit this scope.
I have a 35mm pan,20mm nagler 9mm nagler and a14mm radian,and 26mm
Meade qx.
Suggestions/help please

[sasup]

I run a 17mm ethos on my 12" and its very nice. I also have the 9mm 13mm and 20mm Naglers; also nice. I never use my 24mm pan or my 32mm but its great to have a mix. My advice buy what you can afford, they wont go amiss.

[Satchmo]

Peter - I would recommend a 17mm Ethos as a better all - rounder than a 21mm giving a little more detail and background sky darkness and still quite a rich 3.5mm exit pupil .

[jeff65]

I would give consideration to the 13mm Ethos. The 17mm would likely make your 20mm Nagler redundant while the 13mm would make your 14mm Radian redundant. The 13mm is closer to the sweet spot of a 2mm exit pupil in that scope.

I just did the same sort of research for my 10 inch f/4.7 scope and purchased the 10mm Ethos. I haven't yet had a chance for first light with the combo so I can't comment on the result.

[sasup]

Not sure I agree that the 13mm is a better chose then the 17mm as a all a rounder but it is a fine bit of gear and next on my list. I was told that with a f5 9mm to 32mm is the range and 17 ethos is mid field. Only what I have been told..

[jamespierce]

Owning a mix of Ethos, Nagler and Panoptic EPs myself (including the 35mm Pan and 20mm Nag) I'm not sure I'd spend the small fortune an Ethos cost when you already have the 20mm Nag... It's tiny and great to look through. The Ethos will be massive and significantly change the balance on your DOB.

We have a 21mm Ethos and a 20mm Nag - I far prefer using the 20mm Nag on our dob, we tend to use the Ethos in the refractors.

Perhaps consider a 13mm Nagler to fill our your set nicely ?

Of course I have no idea what other astro extras you have already, but if you don't have a good adjustable chair, a laser for quick collimation (still expect to tweak by eye) and a good dew system (you're going to need this in the flinders) - spend some money on those first. Next buy the three volume 'Night Sky Observers Guide'. Also if you don't have a freezer suit or similar very warm observing gear, that can make a huge difference to enjoyment and how long you stay out looking.

Oh final thought, adding an Argo Navis to my DOB was perhaps the single best thing I've ever spend astro money on.