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Old 12-01-2012, 04:26 PM
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mswhin63 (Malcolm)
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mswhin63 is offline
 
Join Date: May 2009
Location: Para Hills, South Australia
Posts: 3,622
PHD, Pulse-Guiding and EQMOD

Hi,

This is not much a thread to talk about problems or assistance but a huge success.

I have never really been able to capture images greater than 60 seconds mostly because it is difficult to polar align in my backyard. Next door house blocks the celestial pole. Using Alignmaster helped a bit and was able to get approx 120 seconds, then the mount errors would prevent this from getting further.

I recently made a cheap guider and was ready to create a low cost ST4 guide controller when I found EQMOD uses pulse-guiding method. So I downloaded PHD and spent 15 minute watching a video and lo-and-behold I can guide quite well. I didn't need to create the ST4 controller (I will eventually).

Below are some images before and after shots:
1 - 1st image unguided 60 seconds
2 - 2nd image guided 90 seconds
3 - 3rd image guided 240 seconds
4 - 4th image guided 480 seconds

The 95% waning moon does not do justice the images and further to that at longer exposures I reduced the ISO.

The stars are a bit square though and I believe this would be related to accurate polar alignment. The beauty of a good low light webcam is the ability to real-time capture stars instead of long exposure. This should hopefully reduce the updates needed and keep the stars more round.

Still have plenty of mucking around to get the best shot but so far I could not be happier.
Attached Thumbnails
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Click for full-size image (l_m41_0128.jpg)
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Click for full-size image (l_m41_0129.jpg)
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Last edited by mswhin63; 12-01-2012 at 04:27 PM. Reason: OOPs forgot the photos
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