We all knew it was going to happen: I was going to take the CCD plunge. John Hales had been giving me trouble about it for some time. So, I ordered a new ST-7, made by SBIG. It arrived a couple of days ago and I spent the first night installing software and reading the phone book sized manuals. Last night was the first time that I attempted to image with the thing.
The ST-7 is a CCD camera that also contains a smaller guiding chip (ST-4X). One of the draws of this system is that is it a self-contained unit, allowing imaging and guiding with the same unit or camera. One of the drawbacks is that the CCD chip is rather small (most CCD chips are small). The chip in the ST-7 is 6.9X4.6 MM in diameter. One of the merits is that the pixels are 9 microns, allowing high resolution images to be obtained. At the prime focus of the 6" AP, the field of view is 22X14.6 minutes of arc. This will allow some of the smaller NGC galaxies to be captured.
Setting up the telescope proceeded as it normally would. One new twist is the number of power cords needed: One for the laptop and one for the CCD. The G-11 mount was powered from the 12v in the truck as was the Kendrick dew zapper. After plugging things in, I was ready to go......
Ah, what to go after.....well there is the moon, big and bright so lets try that..... After fumbling around for over an hour, I had a little trouble reaching focus.....OK, lets try Jupiter......better luck here, I did finally see something of a round blob with two smaller blobs next to it....say, where are the belts anyway....???? Boy, it sure is cold...(by this point, the low 20s). Ok, enough of this let's try Saturn.....Oh....the #@#@# image is tooooo small...let's try a higher power eyepiece (my Meade eyepiece projection tube screws into the ST-7 body). So in went the 4.8 Nagler....this didn't seem to help....Where is my 4mm Ortho??? OK, into the tube it went and then the camera was into focus mode. Now where is the ....ing planet....Oh (fumble fumble...bump!!) here it is. What the hell is THAT!?!? After messing with the focus, rings began to be visible...after a few more minutes there was Saturn at something like 220X displayed on the computer screen. I could see the Cassini division and some subtle markings on the globe. I took several images and will try a little processing today.
A few points seem to stand out: focus with this thing is critical. The almost any movement of the knob resulted in a BIG change of the image. The field of view is small. Imagine trying to find a small dim galaxy at 300X. While it could be done, it would not be fun or easy. The software is easy enough to use (Software Bisques' CCDSOFT) but now that I have used this thing, I can give the manual a critical reading.
I would say that the first night was something of a success. I now know where the focus for the camera/eyepiece combination is. Thus, focusing next time should be much easier and quicker. This should cut down on the time needed to actually get an image. Also, now that I have some familiarity with the software, the manual will make more sense and I will be able to use all of the little aspects of the program that I had to keep looking up in the manual, in the dark, and in the cold......