Last night had transparent skies but not so steady. With my 4 inch f/15, no luck with E or F in the Trapezium and no joy on the "Pup". The 4th star of Sigma Orionis was harder than I expecded confirming unsteady air. So I decided to play with magnification and see the results. Best view of the dim star was with 9mm/166X. Using my favorite 4.8mm Nagler at 312X the star was 100% invisable. Good demonstration that correct magnification for the conditions is paramount for dim doubles. Bill
Re: Magnification demo
#5723524 - 03/10/13 08:58 AM
It's dispiriting just how detrimental poor seeing can be to doubles and conversely just how flattering in good conditions. There have been a few nights this past winter where either a 26 or 20mm ocular were about max for stellar clarity before bloating or disappearance became evident.