First Light Testing:
This was the first test of the modified Microsoft Lifecam Cinema HD Webcam (LifeCam HD) for astro imaging. Skies were clear on 11/06/09 with a few thin high clouds so I took the opportunity to image Jupiter and the Moon. Mild daytime temperatures dropped to 24 degrees Fahrenheit overnight and the radiational cooling resulted in the usual bad seeing we are cursed with in Northeast Pennsylvania. Under these seeing conditions, I would not normally attempt planetary or lunar imaging.
Over the years I have imaged with a variety of webcams including the Philips Vesta webcams, Philips Toucam, Logitech Fusion and Logitech Pro 9000. During this first astro-imaging test of the LifeCam HD, I found it to be a very light sensitive webcam. When imaging the Moon, I needed to set the BRIGHTNESS to minimum, CONTRAST to maximum, and the EXPOSURE to its shortest setting. During these test images it was almost Full Moon. I found that the webcam's auto exposure setting was very useful for imaging the Moon. In "Auto Exposure" mode, I was able to scan all areas of the nearly Full Moon, and the exposure setting was actually beyond the shortest exposure setting that I could adjust manually. Since the "Auto Exposure" feature was enabling shorter exposures than could be set manually for bright objects, I thought maybe for very dim objects, the "Auto Exposure" feature might enable a long exposure mode. This was not the case when I tested it on a bright globular cluster.
Jupiter:
The webcam was used with a 2.5X Televue Powermate in my 20 inch Starmaster Dobsonian with GOTO Skytracker. The webcam image was kept centered on the notebook display using a wireless control system; see Honis Ground Control.
2 minute video files of Jupiter were captured using three different video capture programs:
I mostly used the HD resolution of 1280X720 for the videos, but also captured at 960X544, 800X600 and 800X448.
Despite the poor seeing, I imaged Jupiter to get experience with the webcam and its settings. Achieving focus was difficult because of the poor seeing, but to help with focusing, I set the webcam in a low resolution mode and applied the 4X magnification mode in the software driver. In 1280X720 resolution mode the webcam captured video at a maximum of 10 frames per second. After the imaging session, I found that if I don't install the Microsoft-provided driver for the webcam, a faster capture rate of 30 fps is possible.
When imaging with the Microsoft LifeCam software, the resulting video file is in the Microsoft .WVM format. This is a disadvantage in that all of the astro-image processing software that I use can open .AVI video files, not .WMV files. For the .WMV files that I captured, I used the free software SUPER to convert the .WVM files to uncompressed .AVI files. When imaging with non-Microsoft capture software, the more astro-friendly .AVI video format files are recorded.
My processing workflow for the captured Jupiter video files was:
Images:
Jupiter was imaged as it set beginning at 6:05pm (32 degrees elevation) until 9:00pm (22 degrees elevation). A two-minute video file at 10 frames per second capture rate provided 1200 frames. About 60 frames were stacked n Registax 5 for each image.
6:05pm:
7:19pm:
7:34pm:
8:14pm:
8:30pm:
2.7 hour Animation:
13 frames - Animated GIF - 6:03pm to 8:40pm
11/06/09 - Lunar image taken same night
Because of poor seeing, only 3 frames were stacked in Registax 5. Crater Theohilus on upper right corner and crater Piccolomini on lower left corner. Reduced to 1000X550 size for display:
Lunar videos to be posted soon. Next time out I will do comparison tests to the Logitech Fusion webcam and Canon 450D DSLR using video mode capure.
Mars - 1/23/10
Seeing was poor and with the temperature dropping to 15 degrees Fahrenheit, there was a lot of blur/distortion from radiational cooling in the captured AVI file. My scope and everything around me was covered in heavy frost. Mars was near its highest elevation (67 degrees). I was unable to use multipoint alignment in Registax 5 because of the poor seeing as I could not avoid seams in the image after many tries. Surprisingly, I tried the free software AVISTACK because I heard it works better on lunar processing during poor seeing, and it worked on Mars. I first selected 148 better frames from the 7236 frames of the 4 minute AVI file by eye and aligned/stacked them in AVISTACK.
20 inch Starmaster was used with 5X powermate. AVI captured at 1280X720 HD resolution with frames captured at 30 frames per second using the lossless Huffyuv codec.
Mars - 2/16/10
Desperate to image Mars, I captured this image while it was snowing. There was a sucker hole in the clouds that opened up long enough to capture a three minute AVI file. Seeing was poor. Temperature was 19 degrees Fahrenheit. AVISTACK was used to stack 95 frames.
Mars - 2/21/10
Another try at Mars during very poor seeing. Temperature was 14 degrees Fahrenheit. AVISTACK was used to stack 140 frames from a total of 7217 frames of a 4 minute AVI file. 20 inch Starmaster was used with 5X powermate. AVI captured at 1280X720 HD resolution with frames captured at 30 frames per second using the lossless Huffyuv codec.
Mars - 3/08/10
Another try at Mars during very poor seeing. Temperature was 21 degrees Fahrenheit. AVISTACK was used to stack 128 frames from a total of 7200 frames of a 4 minute AVI file. 20 inch Starmaster was used with 5X powermate. AVI captured at 1280X720 HD resolution with frames captured at 30 frames per second using the lossless Huffyuv codec.