Quote:
Originally Posted by AdamJL
So I have two guiding setups.
1. ASI 290MM Mini with a 50mm SkyWatcher guidescope
2. Another ASI 290MM Mini with the William Optic 32mm guidescope
It's obvious, but the 50mm scope gives me much better star selection. It just lets more light in. With the WO I can tell the difference when I start taking frames compared to the other scope. It's dimmer, and stars aren't as punchy.
I also find getting focus with that scope a bit harder than the SkyWatcher
That said, it's a great size for a portable solution. But my advice would always be to go for more aperture, yes even on the guide scope.
As for the camera, the 120MM Mini is a good camera, but that 290MM is super super sensitive.
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Thumbs up to the 290MM
I use a 120MM standard in my Orion 60mm guide scope with helical focuser on both my 6 and 8 newts which work well at 3.9:1 guiding image scale.My new 10 f5 CF newt is a big long tube and most recommended an OAG for its 1250mm focal length but I decided to go guide scope again ( Orion 60mm again ). Due to minimal flexure in Carbon fibre and using the 290MM due its smaller pixels and maintaining a 4:1 guiding image scale, the 3 sessions I had so far have been good around 0.60 to 0.70 arc sec total. The 290MM has a much higher QE and sensitivity than the 120MM. Although being so sensitive, the 290MM does require good focus to get the best out of it. In PHD2 I use Gain 60 which equates to a Gain of 210 ( native driver ) which so far works well
Martin