Quote:
Originally Posted by 209herschel
I'm now thinking that the 8mm magnification won't be enough. I've got a 9mm plossl and while the better quality, greater AFOV might be great, I guess it won't increase the size of the view.
After reading a few things and getting some responses along the same lines as yours, I'm now thinking of something in the range of 5-7mm. If I can get by without glasses, I'll definitely go the ES 6.7mm. I'd love to get the Vixen LVW 5mm. Then if I hold off, the Delos 6mm at the end of the year would be my ultimate choice. Would you agree that the quality runs in this order?
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I can't comment on any of those eyepieces, since I haven't tried them.
If you are pushing your dob around though, you'd definitely want something with at least a 60 degree or better field of view. The 50 degree ones are do-able, but do get annoying.
The other factor that isn't mentioned much is the size of the sweet spot in an eyepiece. The eyepiece I've used most over the years has been my old 6.4mm 5 element series 4000 Meade Superplossl. When S&T did a comparison, they found that the Televue Plossl was slightly better at the sweet spot than the Meade, but that the Meade had a much bigger sweet spot covering most of the field. See the problem? While better, the Televue would be harder to keep in the sweet spot for the best view than would the be the case with the Meade. So try keep an eye out for this factor in reviews that you read for the wider angle eyepieces -probably the newer Televue eyepieces address this.
Also, a lot depends on where you live, and how quickly your dob cools down, and how well collimated it is. The best views of the planets I've ever seen with any of my telescopes have been through my 14.5" f/4.5 dob - but that was extremely rare and always at the end of a four hour observing session. So - depending on circumstances, you may not actually wind up using the expensive eyepiece that much or you may. Perhaps if you got an inexpensive Barlow and used it with your 9mm, you'd get a good idea of how quickly things settle down, and how often you would use a better quality eyepiece.
Regards,
Renato