I wonder if the FOV of the EPs plays a role in this? WHat I mean is , do Naglars with their 82º fields show more coma than the Vixen LVW's with their 65º fields?
Yes , because Naglers don't correct coma, but they do correct off-axis astigmatism . The edge of the field in the Vixen of the same focal length would be worse as it is probably not as well corrected. Only a Parracor or similar will correct the coma, which is by far the least dominant aberration compared to filed curvature and astigmatism.
But even a Paracorr can't fix an 'ordinary' eyepiece, so don't buy one unless you are willing to get serious about your oculars
But if you do spend serious money on quality eyepieces and have a scope of f5 or shorter, you're missing out big time on performance you paid for if you dont use a paracorr imo.
Its not only coma thats corrected, it also helps as a field flattener and in that regard alone it improves performance of certain naglers and pentax models affected by field curvature.
Yep. I noticed a lot less field curvature in my 28mm UWAN with the paracorr in the 22" F3.6. This was noticeable even compared to F5 scopes without the coma corrector. In these scopes the outside and inside of the field did not reach focus at the same time.
But if you do spend serious money on quality eyepieces and have a scope of f5 or shorter, you're missing out big time on performance you paid for if you dont use a paracorr imo.
Completely agree.
The moment I saw the difference one made to the eta carina nebula on-axis never mind at the edges I was sold. The second biggest improvement I made was over-sizing the secondary mirror which really helped to illuminate the edge of the field with the Nagler.
Find some very faint stars at the limit of detection in centre field. Once moved off centre they disappear, with the paracorr they do not. Witnessing that convinced me and that its not just about aesthetics alone.
Thanks all. It is actually quite an adrenaline rush as you press the open button in your email for your first look at your new scope. Picking it up this weekend, the weather is naturally looking like garbage.
Almost there now....
