Thursday, January 3, 2013

Lodestar rocks!

Last night, I tried again to setup autoguiding with Lodestar/SkyX. First, I had some weird artifacts in the Lodestar image. But after a while they went away. When I then started using it, I couldn't believe how many stars it picked up. The Orion 3MP autoguider would normally pick up a few faint stars in any image. Lodestar had almost 100 stars - and all of them very crisp and clear. Unfortunately, I didn't store any images for comparison.

Then I calibrated my scope in SkyX - I had to set the calibration time to some really high values (120 seconds!) But after that was done, starting guiding was a breeze. In the end, I suffered the same image shift issue that I had with PHD. It must be either bad polar alignment or shift between the guidescope on top and the main scope. I am looking forward to seeing how this will work once I can use the OAG (still waiting for the filter wheel :-(

Just for fun, I then wanted to take some guided images (without filter). But I forgot that SkyX by default always wants to take a dark image. So, when I came back an hour later, all I could see was a popup box saying that I need to cover my scope and press OK... Well, it was only a test, but I have to remember that in the future!

At the beginning of the imaging session, I tried to use the CCD camera for 2 star and polar alignment. But all I got was a black image - no stars. Not even when I put a light in front of the scope did it catch anything. I finally realized, that the (new 3 Ampere) fuse blew again and that the camera didn't get any cooling. It was all the way up to 13 degrees - which apparently is so high that you don't see anything. After I started cooling it, I did the alignment again. The field of view of the CCD camera is so small, that I needed to center the star very well in the starfinder. What helped was to use the lodestar with continuous photos as well. Because of the larger field of view, it showed the star immediately. I then used its image in SkyX to do a rough alignment and then the star would show up in the field of view of the CCD and I could center it there. Also, having the crosshairs in the camera displays in SkyX helped a lot! After the first 2 or 3 stars, all subsequent stars showed up immediately in the CCD camera and alignment was a breeze!

Over the weekend, I will read more about autofocusing with Robofocus. There are lots of threads on the bisque forum. And I should also try the collimation with CCDInspector. What I did find out was that moving the focus in still works (yesterday, I thought that it won't stop). This is the backlash setting that I set (as recommended to a really high value). Robofocus oversteps by this many steps and then moves the focuser back.

So, I still have to figure out what to do about the fuse for the CCD camera. Starlight Xpress support said that 3 Ampere should be high enough. But when I turn on the camera it can have a REALLY high spike. Maybe I follow John Smith' recommendation and not use any fuse for the camera at all.

And the cable in the 12 Volt AC/DC converter broke :-( Need to get a new one. That's the second cable that broke (the other was the original Laptop power supply). Ordered a new one. But I have to figure out what to do about cable breakage...