Merlin
Im looking at the Lumicon Newtonian OAG at the moment as a replacement for the Orion OAG. Although thtter works fine on stars at 1800mm focal length it starts to fall away at 2500 FL. Although I must admit I was able to do a 40 min sub at 2500mm FL and still get round stars (see
http://www.iceinspace.com.au/forum/s...ad.php?t=73559).
But thanks for the advice.
Allan