Last weekend occasioned a rare day for this time of year. Saturday was a day of high visibility, high transparency, and moderate seeing. It would have been irresponsible of me to not take full advantage of that, and so I did. Starting at about 10:30 AM I was set up and shooting the sun. I wanted to focus on detailed surface areas more than the full disk this time so I started pointing at active regions. I have discovered, and I should have expected, that the narrower the bandwidth I tuned into, the smaller the sweetspot became in the field of view. I wanted to get award winning detail with a 60mm aperture that would rival a space satellite image. OK so I was over ambitious a little bit, but that’s how I roll. The narrower I squeezed the bandwidth (I was well within 1/2 angstrom) the less total surface area I collected. I did get some good detailed shots of AR11704 but I can only get so close. I have also discovered increased difficulty of producing a flat frame with the new larger camera. The level of detail makes a blurred flat frame too detailed and when registering the frame the software over-corrects and produces noise in the image. I will have to find a new solution to this. There are a lot of DMK41 users out there, so I’m sure I will find the answer. All in all I snapped about 100,000 images but in the end I didn’t actually get much I could work with. I am still trying to pull data out of the raw images at night after work, but have had little success. I was able to get a nice prominence or two and will continue posting them as I get more processed.
The sun reaches a point in the afternoon sky where the atmosphere becomes too thick at low angles to get anything good. I packed it away around 4pm and went out for dinner. I was amazed at how clear the skies were well into the evening. I decided to pull out the big guns and go for some night shots. I started with the intent to image only Saturn and the Moon. Saturn was not visible above my horizon until about 11:30 pm so I had time to kill. I pointed to M51… but I discovered serious problems with my scope. I was drifting again and the collimation was again off. I have been having trouble with this before. I recollimated and did a full focus limits test along with several 2 star re-alignments. I was able to fix the collimation, at least for the night, but I must have a drag in one of the tracking directions. It’s an Alt-Azimuth fork mount so both directions have to move to track the earths rotation. By the time Saturn crested above my horizon I had gotten things ‘good enough’ for Saturn. I started shooting in monochrome only as I didn’t have my filters set up for the new camera yet. It didn’t turn out too bad. I did’t trust my histogram on this one, the images appeared overexposed so I dropped the f/stop back 2 spots and took some darker images. I was able to get better ring structure and then I just increased the exposure with software later to show the detail.
The Moon made it’s expected appearance at about 1AM through the trees. I started focusing in on the terminator waiting patiently for a full disk so I could a get a flat frame. My field of view was pretty narrow, so I decided to get as much as I could to put together a composite. I took 22 .avi files consisting of 1500 images each. The air was getting pretty turbulent and I was getting worried about losing detail. I spent a few hours trying to get every region lined up in the histogram. I wrapped it all up at about 3:30AM. The telescope was still dry and we hadn’t even hit dew point yet. I wish this would happen more often.
12 hours of stacking post processing on Sunday pretty much encapsulated my day, but it was cloudy so it all worked out. I had to get some beta
software from microsoft designed for panoramics to stitch the images together because the Moon had rotated in the field of view over the 90 minutes or so I was observing. While I did not get the level of detail I wanted at the full resolution size of each part, the overall composite, after reduced in size, turned out to be quite nice. No complaints this time. I also developed a new set of goals specifically focused on the Lunar surface. I hope we have more clear nights this summer.
I’ll post more stuff as I get it processed. As you can see, it takes much longer to process the images than it does to collect them.