Enrique
04-03-2009, 09:05 PM
All pictures taken with Canon 40D, LX200 Classic 12” at F6.3. Auto guiding with ED80 and QHY5.
M42#1, my first try with M42, Dec 2007.
Issues: focusing-collimation, polar alignment, comma, scope balance, tracking and vignetting.
I worked in improving the focusing and the collimation. The stars were not round in the live view of the camera. I did some work with the collimation, I am still not happy, and I changed the plastic bearings of the focuser to reduce the backlash. It improved quite a lot, I could focus better.
Polar alignment: I did the polar alignment manually. I had all the classic bad pictures that show the stars like long sticks. Fortunately, I started using the program EQAlign that improved the alignment and had a positive impact in the tracking. Last time I used the program the alignment was so good that I could have shut down the Dec motor.
Tracking: it was being affected by the scope balance, bad polar alignment and lack of experience with the tracking software. I started using Guidemaster with good results but with the tendency to have errors in RA (the stars where like ovals elongated in RA direction). I did not use PHD because I had troubles with the serial port and the ASCOM drivers (part of this issue is fixed but still something is not working 100%).
Comma: some stars looked like “hamburgers” (with a piece of meat in the middle). Most of them were cropped from the M42 image. The main reason for the heavy comma was the position of the focal reducer. I had it at 105 mm from the sensor. The design distance is 87 mm. I changed the T adapter for a shorter one and the comma was reduced substantially. I have included a picture of the Omega Centaury globular cluster that shows comma clearly at the bottom left corner. The picture is heavily cropped at the other corners.
Vignetting: I think that getting rid of the vignetting by using Photoshop reduces the extension of the nebula. One solution is to use an Eye Opener or a Giant Easy Guider to send more light to the sensor. This is a well know issue with the LX200 and the focal reducer.
M42#2: this is my latest picture. They were taking at the end of Nov 2008. Besides all the improvements noted above, there is still room for more, I have spent time in picture processing. I am using DSS, IRIS, and Photoshop. I am happier know, I like the shape and size of the stars, the improvement in the details of the nebula, despite fighting with the vignetting, and, of course for the purists, the colours.
Any comments in how to improve my results are welcome.
Thanks for looking,
Enrique
M42#1, my first try with M42, Dec 2007.
Issues: focusing-collimation, polar alignment, comma, scope balance, tracking and vignetting.
I worked in improving the focusing and the collimation. The stars were not round in the live view of the camera. I did some work with the collimation, I am still not happy, and I changed the plastic bearings of the focuser to reduce the backlash. It improved quite a lot, I could focus better.
Polar alignment: I did the polar alignment manually. I had all the classic bad pictures that show the stars like long sticks. Fortunately, I started using the program EQAlign that improved the alignment and had a positive impact in the tracking. Last time I used the program the alignment was so good that I could have shut down the Dec motor.
Tracking: it was being affected by the scope balance, bad polar alignment and lack of experience with the tracking software. I started using Guidemaster with good results but with the tendency to have errors in RA (the stars where like ovals elongated in RA direction). I did not use PHD because I had troubles with the serial port and the ASCOM drivers (part of this issue is fixed but still something is not working 100%).
Comma: some stars looked like “hamburgers” (with a piece of meat in the middle). Most of them were cropped from the M42 image. The main reason for the heavy comma was the position of the focal reducer. I had it at 105 mm from the sensor. The design distance is 87 mm. I changed the T adapter for a shorter one and the comma was reduced substantially. I have included a picture of the Omega Centaury globular cluster that shows comma clearly at the bottom left corner. The picture is heavily cropped at the other corners.
Vignetting: I think that getting rid of the vignetting by using Photoshop reduces the extension of the nebula. One solution is to use an Eye Opener or a Giant Easy Guider to send more light to the sensor. This is a well know issue with the LX200 and the focal reducer.
M42#2: this is my latest picture. They were taking at the end of Nov 2008. Besides all the improvements noted above, there is still room for more, I have spent time in picture processing. I am using DSS, IRIS, and Photoshop. I am happier know, I like the shape and size of the stars, the improvement in the details of the nebula, despite fighting with the vignetting, and, of course for the purists, the colours.
Any comments in how to improve my results are welcome.
Thanks for looking,
Enrique