Quote:
Originally Posted by mental4astro
As Newtonians present such technical difficulties, and Newt specific EPs are so expensive, finding inexpensive and optically good EPs can be difficult - but it's not impossible!
There's a trick to this. And it comes from the complex nature of contemporary EP designs meaning that there are some convex specific eyepieces that actually do a fantastic job in Newts as well. From a given line of eyepieces, take for example the Baader Hyperion line, every single focal length shows significant aberrations such as astigmatism and field curvature EXCEPT for the 5mm! The 5mm Hyperion is sensational in Newts as fast as f/4.
There may be just one, or two or three individual EPs from a whole line that perform really well in Newts, so it is important when reading reviews to make a point of finding out what scope an EP is being used in so you can figure out if the EP being reviewed is good for your Newt or not. As most people do not know about optical matching, they may write off an entire line wholly because they used the EP in the wrong scope design. This is VERY COMMON. The amateur astronomer in the know can "read between the lines" of these reviews.
For some of these less expensive gems, you may need to cope with some mild aberrations, but these will be right the very edge of the field of view, where no one does any serious observing. Accept this, and some absolute and less expensive gems can be had!  |
I've seen the Hyperion at Astro Anarchy for a decent price...I might start with that, but worried a 5mm would only be useful with perfect conditions and optimal cool down.