I've wanted to get a good stack of Venus video frames near inferior conjunction. After day after day after day of rain, Dec 28 was my first chance. Venus was 8.1% sunlit this twilight evening. I loaded the 10" LX200 and brought it up to Horticulture Hill (formerly, Observatory Hill). But the seeing was not only poor (which I expected), but the scale of the atmospheric convection cells was small compared to the angular diameter of Venus, giving strongly spatially varying distortions on all frames. Not sure what'll come out (I'm waiting for a new laptop with a 1GB of memory to arrive before downloading off the miniDV). For now, enjoy this image of sunset...

I tried again on Jan 6, 2006. This was probably the most ideal day; Venus was still about 8 degrees up when the sun was -2 degrees and it was dark enough to first spot it in binoculars. And, Venus was only 1.8% sunlit. I drove toward Cabrillo Observatory, but fog was forming over Santa Cruz, and the familiar finger of fog which climbs up to Aptos was also forming. It looked like a poor bet to try Hort hill, so I packed up the 10" and pondered as I drove away from the observatory. I decided the best bet was to drive up to the top of Rodeo Gulch. But Friday afternoon traffic was slow, and as I drove up the Gulch, my hopes of getting set up in time were low. I got to the spot I figured would have a clear horizon, but the sun and Venus set so far south that a ridge was in the way. I drove another few hundred yards and found a spot with about 3 feet of width where one could hope to see where I thought Venus would be. I set up as fast as I could, and realized that there was no way to do an accurate 2-star alignment of the LX200 10" - it was too bright to see any stars. So, I guessed where Aldebaren would be, told the LX200 that's where it was, then guessed where Polaris would be, aimed the scope there and didn't even bother to look in the finder scope to see if the stars could be seen, time was short. And..... I guessed well! when I put the scope on Venus, it tracked well enough to get my imaging, even at the highest zoom so that Venus filled the frame of the camera.

Dec '06 - One year later, I finally get around to working on this project. Original footage was taken using a Canon ZR45mc camcorder and MaxView 40mm eyepiece in afocal projection through a 10" LX200 telescope. I used Adobe Premiere 2.0 to capture several video sequences from the miniDV tape. These turned out to be unreadable by Registax, so I next opened up these Premiere .avi output files into VirtualDub (freeware) and immediately re-saved them ("save as avi") with a new name. This was suggested on the web in a few places so I tried it. It worked! This file could be read by Registax. Otherwise, I was getting a "failed to start avi decompression" error in Registax. In fact, for my longest avi file, even saving it in VirtualDub, I was able to open it in Registax and have it go to work, but when it got to just over 2000 frames it came back with the same dreaded "failed to star avi decompression" error.


Dec 28. My first attempt at avi file stacking. Best 91 out of 225 frames (70% quality cut in Registax 4). Then in Photoshop CS2: levels, cropped. Sharpening just didn't work.

This was from an 885 frame sequence with lower exposure times on the ZR45 camcorder at the time of recording, hence the stronger colors. This was shot on Jan 6 with Venus only 1.8% sunlit and only a couple of degrees above the horizon. Best 166 out of 885 frames (80% quality limit), gradient method aligning on one horn of cresent. Saved as 16bit TIFF and Levels, unsharp mask in Photoshop CS2, and mild cropping.

One of the best single frames from Jan 6, Photoshop CS2: 2x unsharp mask, sharpen edges, sharpen more, gaussian blur, AstroTools 'space noise reduction', levels, cropped.


From same 885 frame sequence as at left, but this time only the top 23 frames retained. The final image suffers for keeping fewer frames and pixel-to-pixel noise is evident. Aligned on horn as before.

Jan 6, this time using the entire disk to align with, and keeping all 885 frames. Photoshop CS2: smart sharpen with large radius 400%, AstroTools 'local conrast enhance', cropped. Using the entire planet was a tip gotten from Don Parker's excellent Sky&Tel article, when seeing is very bad. It clearly makes for a sharper stack.