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A quick try at the Horse Head...

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#1 jhayes_tucson

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Posted 22 January 2014 - 03:27 PM

Here's a quick try at the Horse Head using a Hyperstar/C14. Freezing fog shut me down early so this is only about 26 minutes with an unmodified Canon 7D. There are some minor processing artifacts along with some optical artifacts due to an slowly iced up front correct plate during the exposures, but hey, you can see the horse head! Now I'm inspired to get it better (yep, I'll probably need another camera!)
John

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#2 mpgxsvcd

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Posted 22 January 2014 - 03:30 PM

Wow. That looks incredible for an unmodified camera in such a short time. It looks like you definitely used a filter because of the star color. What filter was this? Also what were your exposure durations and ISO? What scope did you use.

Tell us more. Inquiring minds want to know.

#3 jhayes_tucson

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Posted 22 January 2014 - 03:47 PM

Sure…happy to tell you more. ISO was 800, OAT was probably 26 degrees so thermal noise was low. I took 5 subs at 30 seconds to check position and tracking and then managed to get 13 subs at 60 seconds before the corrector iced up. The last few images probably had a fair amount of fog freezing to the optics before I discovered the problem. That almost certainly caused the big halos around the bright stars. The Hyperstar operates at f/1.9 on the C14 so it gathers light pretty fast. I was also using an IDAS LPS-D1 light pollution filter. Saturation is turned up pretty high which amplifies the color of the halos around the bright stars. Diffraction from the small water/ice drops may have caused some of that color (just a guess.)
John

#4 nodalpoint

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Posted 22 January 2014 - 03:59 PM

Looks nice.

Just FYI, all the pictures posted seem to be flipped. I guess from the SCT.

#5 srosenfraz

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Posted 22 January 2014 - 05:07 PM

Very nice looking HH, John - surprisingly nice reds for an unmodded camera. Imaging at f/2 sure has its advantages!

Nodalpoint is correct about the image being flipped. You can correct it by flipping (or mirroring) the image horizontally.

Congrats on such a nice image.

#6 jhayes_tucson

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Posted 22 January 2014 - 05:17 PM

Very nice looking HH, John - surprisingly nice reds for an unmodded camera. Imaging at f/2 sure has its advantages!

Nodalpoint is correct about the image being flipped. You can correct it by flipping (or mirroring) the image horizontally.

Congrats on such a nice image.


Ok guys, you are right. Putting the sensor at the prime focus flips everything and I didn't think much of it until you guys pointed it out. Thanks for the tip--I'll flip photos from now on. So, here it is as you would see it in the sky.
John

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#7 gsrs.family

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Posted 22 January 2014 - 06:14 PM

Sure…happy to tell you more. ISO was 800, OAT was probably 26 degrees so thermal noise was low. I took 5 subs at 30 seconds to check position and tracking and then managed to get 13 subs at 60 seconds before the corrector iced up. The last few images probably had a fair amount of fog freezing to the optics before I discovered the problem. That almost certainly caused the big halos around the bright stars. The Hyperstar operates at f/1.9 on the C14 so it gathers light pretty fast. I was also using an IDAS LPS-D1 light pollution filter. Saturation is turned up pretty high which amplifies the color of the halos around the bright stars. Diffraction from the small water/ice drops may have caused some of that color (just a guess.)
John


Very nice for the unmodified camera, and you gave lots of information. Thanks






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