Well it's time to upgrade to much better eyepieces. At the moment have just the 'cooking' versions that came with the scopes, possel and a celestron 8-24mm zoom. So I'd like a bit of advice what type to get, Nagler Delos etc. etc. and also the advantages and disadvantages of the types. Oppps forgot to say I have a 6" sct and a 8" reflector with 2" focuser, and I'm going to upgrade that 8" to a 12"
If upgrading from the 8" you will want eyepieces that handle a faster scope. As you have mentioned the likes of the televues.
What are your target objects?
For my future use, and I pretty much am interested in everything from planets to DSO's, in a 10" or 12" dob I've shortlisted pentax xw10 and denkmeier 14mm based on the excellent feedback here for dso and cluster use. I require good eye relief as I use eyeglasses and these both provide that.
This is my strategy for setting up a nice eyepiece lineup. Find the longest focal length eyepiece that will give you an exit pupil around 6mm to 7mm. Then choose the shortest focal length eyepiece that will give you a regularly useful magnification under the sky conditions you observe. Now fill in the gap between these extremes with logical steps in focal lengths, which might require another 2 or 3 or more eyepieces, depending how many telescopes you end up with.
The first focal length to buy, and the one to spend most cash on if you can only buy one expensive eyepiece is a focal length that is twice your telescope f/ratio. That eyepiece will give a 2mm exit pupil which is a very good place for observing a whole range of targets.
Once you have figured out the focal lengths you want, it's time to choose the brand. You list some TeleVue's, I like them a lot and have tended to keep buying them. I would suggest you get along to some star party's and try a few out before you part with your own cash on them. There is plenty of info around the net reviewing the TV eyepieces and I'm sure you will figure out the advantages and disadvantages of each.
What eyepieces do you currently have? It may be cheaper to just get a coma corrector like Paracorr or ES HDCC to clean up the views in fast Newtonian then redo your entire eyepiece collection.
On a side note answering your question.
PROS of Naglers, Delos and Ethos:
Sharper views, better corrected field, less light scatter improving perceived contrast, more eye relief - thus more comfortable viewing and larger apparent fields of view from starter eyepieces.
CONS:
They can be quite heavy and cause balancing issues.
Your wallet and significant other will hate you. Not might hate you. They WILL hate you.
If upgrading from the 8" you will want eyepieces that handle a faster scope. As you have mentioned the likes of the televues.
In a 10" or 12" dob I've shortlisted pentax xw10 and denkmeier 14mm based on the excellent feedback here for dso and cluster use. I require good eye relief as I use eyeglasses and these both provide that.
I have used both of these eyepieces extensively over the past decade in telescopes from 4" to 36" and as fast as F4. They are both outstanding eyepieces and certainly the equal of anything Televue has ever produced.
Oppps forgot to say I have a 6" sct and a 8" reflector with 2" focuser, and I'm going to upgrade that 8" to a 12"
