gerharden

I had a test last night (NGC 3621) and really struggled to find a guide star. The one time I got it right, it worked well. 2min exposure with no issues. I have changed to orientation of the guide camera to aligned with the main camera. I decided to drop the prism deeper into the light path, which does give me more light on the Guide Camera, but does introduce more shadow on the main camera. Any suggestions with regard to settings in PHD for the ASI120MC-S to improve its performance? Below are photos of the changed configuration: Image through the ASI120MC-S Image through the ASI1600MM Pro

Hi Brown Dwarf Not that I'm an expert at all, but from what I have seen and read, it looks like long edge to long edge, so your first image. Gerhard

Hi Mchael, Thanks for that. Did not even think of rotating the periscope to be horizontal to the main camera. The one video I watch, also show the skewed shadow, so I thought that was normal I have also rotated to guide camera to be 90deg to the main camera (USB port pointing to the main camera). Had to make some spacers to get that right. I will have to wait for some clear skies to try this out. With the periscope being horizontal to the main camera, it might be possible to drop it a little bit further into the light path, without affecting the main camera too much. The vignetting is not that bad. The attached image was stretched so it looks a lot worse. I have attached an un-stretched version.

Hi All, Need some guidance with regard to the setup of my ZWO OAG. I have been reading lots of posts and watched a number of YouTube video's. I have it setup, but I have a couple of questions. Firstly this is my setup as shown in the picture OAG Setup. Celestron 11" SCT + Celestron f/6.3 Focal Reducer + Celestron T adapter + M48 - M42 adapter + ZWO OAG + 11mm spacer + T2 - T2 adapter + ZWO EFW mini + ASI 1600MM cooled. I use a ASI 120MC-S as my guide camera. I moved the prism into the light path far enough so as not to block too much of the main camera (See stretched MasterFLAT_-15C_2x2_Lum). Then I focused the the main camera and the guide camera on a piece of paper about 18m away (see picture Focus Target). I noticed two things. 1) The image from the guide camera has about a third of the image blocked (See image ASI120MC-S). Is this normal? I do not want to move the prism deeper into the light path, or should I? 2) Also the main camera and the guide camera are pointing quite far apart of the Focus Target. Is this also normal? I suppose it does not make much difference when looking at the sky. Your guidance (no pun intended) would be appreciated.