Received the secondary heater for the RC today. Installed as per instruction and gave it a rip tonight to see what its like. It certainly keeps the dew off but the fit isnt so good and now my star shapes are horrendous. Examples are a 10 min shot from a while ago and varying length shots tonight. The original shot has nice round stars but tonights all have weird flaring, I believe it is because the outer edge of the secondary heater slightly protrudes into the light path. Not sure if I can trim it so there is no protrusion or not. These pics have only had a stretch. Any suggestions appreciated, especially from those that have added the secondary heater to their RC's in the past.
The first 2 things I would be checking is if the collimation of the secondary moved while you were fitting the heater or possibly your guiding is not as smooth as it could be because of the seeing conditions tonight.
How far does the the heaters edge protrude from the secondary holder, photo would help.
Thanks for the suggestion Rick, unfortunately I tried the other night with different settings from off to full and everywhere inbetween with no difference to the strange flairs in the stars.
It could well be the hairy bits, here's what a bit of spider web next to the secondary showed up like on an rc6 image. I thought it was a smudge on my sensor but it moved between frames.
Collimation checked and is good(probably needs small tweak but not bad). Just trying with secondary heater turned down low again, I probably didn't let it cool long enough to make a difference last time. fingers crossed as i tried with heater off and apart from a slightly larger diffraction spike it looked better.
That spider web would have driven you crazy to find mate.
Shane
That web messed up a lot of subs (it really stands out on the overexposed subs), but was quickly found in daylight. I try hard to keep the optics clean, but I'm dreading the time when I have to pull it apart for a mirror wash.
