Periodic Error Correction.

Sunday night I thought I would attempt to train the drive for periodic error correction or PEC.  It took longer than usual to get the drive aligned tonight. I suspect because I dumbly sync-ed Polaris after each drive Azimuth/Altitude(tilt) adjustment. It was unusually humid and transparency was mediocre. As one might expect clouds moved  in ending the night.

It dawned on me that I should simply clear any PEC data that might be polluting the drive and causing it to correct for non-existent errors. Tonight I bring the scope upstairs and retrain the RA/DEC axes. This is different from PEC training. If I get a break on the sky I'll try imaging one easy DSO. There are few visible from my tree obstructed terrace between 9-12 midnight. This weather is really sucking right now.

First Real Night Out

I caught a break in this almost two week cloudy, showery, foggy spring weather pattern and managed to get the telescope over to the local Donovan elementary school on Friday night. While clear there was high cirrostratus and transparency was poor. I decided to try my hand at M3 and M13. Both are near the zenith between 10 and midnight.

Last winter the Meade 1697 computer drive system needed a repair and I opted to have it upgraded to an AutoStar I. I have mixed feelings about the Autostar. The good news is that alignment and tracking appear to have improved. I rarely have to spend as much time as in the past getting the GEM aligned with Polaris. On the other hand Autostar's usability and documentation is abysmal compared to Meade's original #497 controller. The menu system has become deeper and adds extra annoying steps.

That rant said Friday's results were a mediocre start. Using Arcturus I got rough focus. I then moved over to M3. I fine focused on the globular cluster using 1s preview exposures. In color mode the image had a very orange cast which I hope has to do with all the sodium vapor light pollution scattering off the high clouds and smog. I decided to image in B/W.

To my disappointment I was only able to use 2 to 4 sec exposures because of the severe periodic error. I guess my next night out will be devoted to learning how to and tuning PEC.

The focal end of the scope was getting dangerously close to a tripod leg during my M3 imaging session. Rather than chasing M3 to the other side of the GEM I moved to M13 which was now near the zenith. Again with M13 tweaked into focus I tried imaging the globular in B/W and color. Again the color images featured an orange cast and washout of the brightest stars. I'm not sure if this is a consequence of imaging in JPEG. I'll try using FitsInt, Fits or Fits3D

Barely a first night out

It's been 12 days since I received the DSI-II. The weather has been cloudy with showers with zero clear nights until last night. I wasn't convince the clear sky would hold so I only set up the scope on the terrace. For local observing I usually take the scope to a local elementary school parking lot/play ground. Trees block most of the view from the terrace. However one DSO the Sombrero galaxy was available.at 10PM. I detest daylight saving time.

Scope aligned I used Spica to get a rough focus. From Spica I jumped over to M104. A group of stars in the field to the left of M104 served as a fine focus. To my delightful surprise I could just make out the core of the Sombrero in 1 sec exposure preview mode. This is about as far as I got. I made the mistake of setting dark frames to 5 per average. By the time I got to imaging the Sombero it was moving behind one of those inconvenient trees.

Tonight it's back to crappy, overcast New England spring weather.

Familiarization

The DSI-II comes with Meade AutoStar Suite software on CD. However, I immediately downloaded the latest version which includes Envisage 7.05 which is the the imaging application for the camera.

The underlying business logic of Envisage automates image acquisition, dark frame subtraction, alignment and averaging of a series of images. This is quite impressive, though during this current spell of wet and cloudy weather I have not had a chance to test this.

The Envisage user interface is not particularly intuitive.  That might not be so bad if the software came with a well designed help system. It does not. Nor do the controls and buttons of the interface give hints.

There is a PDF user manual. There is also a helpful video that gives an overview of the imager's usage. Meade's advertising promises spectacular astro-images on the first night out. With careful pre-outing preparation it's possible but don't expect to get the Fedex delivery at noon and expect to have images by midnight if you've not done astroimaging before.

Introduction - Just bought a Meade DSI-2

I've been a skygazer since my parents bought me a dinky 40 mm department telescope when I was 9. I got a lot of moon gazing out of that toy which started a lifelong hobby. Fast forward to day and I now use a Meade 127 ED(5 inch) refractor telescope which I bought back in 1990.

In 2001 I decided to try my hand at deep sky imaging using a modified Philips webcam. I tech savvy guy named Bob White from California was kind enough to surgically alter the webcam for me for a mere $60. I got quite a bit of use out of the camera until a couple of years ago when my parallel port equipped laptop died. A native parallel port was necessary to use the camera and as today's laptops lack parallel ports I was put into limbo.

Last week I decided to jump back in with a Meade DSI-II (deep sky imager). The DSI-2 price had recently been cut to $299. I was actually able to score one from Telescopes.com for $285 including Fedex shipping. The  DSI-2 arrived Friday 13.

It's been cloudy and wet since Friday, thus I have had no chance to test the camera astronomically. Current forecasts for this area(Greater Boston) indicate I'll be lucky to give the camera a real world test by the weekend.  Meanwhile I'm familiarizing myself with the camera and the Envisage imaging software.