Quote:
Originally Posted by SkyWatch
Have you considered the Long Perng planetary eyepieces? I understand they are the same as the Orion "edge on", but only $79 at Andrews. I have used the 3mm and 5mm versions and they compare very well with a barlowed Nagler 13, and even my Nagler 3-6 zoom (which is magic by the way!). Not quite as wide-field (55-60 degree) as the Nagler 13, but nice and sharp across the field.
While on-axis performance is critical for any eyepiece, for a non-motorised dob it is good to have a relatively wide sharp field, even for planetary viewing, because it gives you more time looking and less pushing and waiting for the vibrations to settle again. It is really annoying if the image worsens significantly when the planet moves off centre, and this is often the case for budget eyepieces.
The LP's also have a 20mm eye-relief, which is very helpful with glasses and makes a big difference compared with plossls or orthos, irrespective of their cost.
All the best,
- Dean
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Thanks very much Dean. I ended up buying a Tmb Planetary II 9mm to compare with my plossl. 58 degrees field and 12mm eye relief and they're supposed to be pretty good for planetary. I'd never even thought of the Long Perng and I knew Andrews had them. I'll start researching now - I appreciate the advice. The wide and sharp field on planetary is what I'm after before I get something great for dso which will be another topic entirely! Even with the 9mm plossl now, Saturn is pretty much through the field by the time the vibration settles and I've only seen it somewhat sharp when I've put the scope ahead and waited and had the focus on. Thanks again.