skymuster
22-08-2019, 10:26 PM
I had my own NASA moment this week. After purchasing my new dedicated mono astrophotography camera (ASI1600MM) I endured the obligatory cloudy nights for the next 3 weeks solid! I used this time to give my scope a spring clean, including the primary mirror. When the clouds finally broke I was excited to finally experience "first light" with my new camera. The results were, however, underwhelming. I just couldn't seem to achieve sharp focus and my guider was showing every star as a double star! I had the same feeling as the NASA scientists when the first blurry images from Hubble came back.
Here is the original image:
248313
[single 300s exposure, unity gain, Ha filter]
After much head scratching, and a bit of buyer's regret about this expensive camera I'd just bought that didn't seem to work, I found a couple of posts online indicating it could be due to "pinched optics" when I reinstalled the primary mirror. This resonated with me (I recalled tightening the mirror clips) so I set about performing my own "Hubble repair mission". An evening of removing the primary mirror again, lossening off the retaining clips, reinstalling and recollimating and I was ready to attempt "second light". No spacewalks were involved.
When the clouds finally cleared again I was able to take a single test image. I really wasn't expecting much difference but as soon as the exposure was done and the image materialised in front of my eyes, I almost fell off my chair. The grin on my face was almost comical!
Here is the new image:
248314
[single 300s exposure, unity gain, Ha filter]
Like the intrepid NASA astronauts many years ago, my own Hubble repair mission was a resounding success. I had corrected the dodgy optics and now had a sharp image. This hobby definitely has its ups and downs but I am pleased to say this is definitely one of the highs!
I now can't wait to put this camera through its paces and put together my very first narrowband image. Lots of fun times ahead!
Here is the original image:
248313
[single 300s exposure, unity gain, Ha filter]
After much head scratching, and a bit of buyer's regret about this expensive camera I'd just bought that didn't seem to work, I found a couple of posts online indicating it could be due to "pinched optics" when I reinstalled the primary mirror. This resonated with me (I recalled tightening the mirror clips) so I set about performing my own "Hubble repair mission". An evening of removing the primary mirror again, lossening off the retaining clips, reinstalling and recollimating and I was ready to attempt "second light". No spacewalks were involved.
When the clouds finally cleared again I was able to take a single test image. I really wasn't expecting much difference but as soon as the exposure was done and the image materialised in front of my eyes, I almost fell off my chair. The grin on my face was almost comical!
Here is the new image:
248314
[single 300s exposure, unity gain, Ha filter]
Like the intrepid NASA astronauts many years ago, my own Hubble repair mission was a resounding success. I had corrected the dodgy optics and now had a sharp image. This hobby definitely has its ups and downs but I am pleased to say this is definitely one of the highs!
I now can't wait to put this camera through its paces and put together my very first narrowband image. Lots of fun times ahead!