Quote:
Originally Posted by ausastronomer
That is simply not true. I have cleanly split Antares on hundreds of occasions in newtonians from 6" to 25", which is the sizes I have tried on it. The mirror needs to be cool, the telescope needs to be collimated, the optics need to be decent, the seeing needs to be decent and Antares needs to have reasonable elevation, to achieve a clean split. I have also split it in high quality APO refractors down to 4". The smallest being a Takahashi FS 102. The same type of conditions apply when splitting it in a refractor.
Two nights ago at Coonabarabran under reasonably good seeing we split Sirius at 300x in my 18" Obsession and Antares at 200x in my 14" SDM. These were at different times. Had I swapped the scopes around the 14" would have split Sirius easily and the 18" would have split Antares. My 10" SDM has split them both under favourable conditions on many occasions.
I first split Sirius many years ago, when it was infinitely harder due to the closer separation, in my 18" Obsession, under excellent conditions at 1050x (5mm Pentax XW + 2.5x TV powermate).
You should try 1050x in a refractor, (I am sure a 6" APO can pull 175x per inch of aperture)  , it does an excellent job of showing extended detail in targets like the homonculus and planetary nebula like the Ghost of Jupiter (NGC 3242).
Cheers
John B |
Thanks John, I did say "suspect" and am happy to be corrected. The best views of Jupiter I've ever had with any of my telescopes is through my 14.5" dob, but that's only been on a couple of occasions at the end of a four or five hour observing session, and in the middle of rural fields. Unfortunately, I can't do those sessions any more, and have never been able to get anything sharp from my old suburban backyard or current semi-suburban backyard. Even my C8 struggles where I now live - after six weeks of lousy views of Jupiter, Mars and Saturn, I had a friend pop in who I showed them to, and magically, the C8 worked perfectly for a change.
I'll try 175X per inch in my 4" APO when I remount it in a few weeks, though given seeing conditions here, I'm not optimistic.
Regards,
Renato