Hi again,
Thanks for your imput Jonathan
, and your use of a standard to compare the split is an extremely valuable bit of science. I should know better as I come from a chemistry field, lab work etc where we use standards or Media Blanks as we call them, something to reference against. I will do this next time to check for any aberations or reflections from the barlows.
Dennis you have been great with this and I really appreacited the input and and the help
. I have found that SCT scopes can produce extremely bright diffraction rings on bright stars on nights of good seeing (the Meade 8" LX10 showed me this), and hiding any faint secondary. Where with a straight colminated Newt that the tube can be turned in the mount rings, So the spider that causes the spikes don't hide the secondary. An excellent trick, and found very effective a number of times when previously the spike would hide the secondary.
Generally I will not check the current position (angle/seperation) of any double prior to trying to get the split, so if I get it I generally check what I get with what it is suppose to be. If I don't get the split I try and turn the tube to make sure it's not covering it's supposed current position and try again. As I knew where the approx position of the pup was from my previous observation I made sure the diffraction spike wouldn't cover it.
I'll hopefully get some more imaging of this wonderful double with a comparison image (standard) in the next few months.
I'll post what I get here, as Jonathan said there should be a few such images starting to appear when the Dog Star rises in our skies over the next comming months.
Rod