Page 1 of 1

ORION NEBULA at 1,000 frames of 1 second exposures

Posted: Thu Jan 28, 2021 2:53 am
by RickBG
Image
Orion Nebula up close taken on January 23, 2021. I took 17 minutes of exposures (1000 frames of 1 second each) which would be considered very short. Note, the Trapezium (four stars) can be seen when zoomed in.
Hardware:
CPC 800 SCT 8" telescope
ZWO ASI 183 color cooled camera
Optolong L-Pro filter
HyperStar 1.9 focal reducer
Software:
SharpCap Pro 3.3
PhotoShop

Re: ORION NEBULA at 1,000 frames of 1 second exposures

Posted: Thu Jan 28, 2021 2:24 pm
by admin
Hi,

a nice image, captured by an unusual technique. It just shows what modern, low noise cameras are capable of :)

Cheers, Robin

Re: ORION NEBULA at 1,000 frames of 1 second exposures

Posted: Thu Jan 28, 2021 3:56 pm
by turfpit
Very nice image.

You might find these interesting https://www.astrokraai.nl/viewimages.php?t=y&category=7 from the author of Autostakkert. many are 2000x1s.

Consider not having an email address as your username - it is open to spammers as it is.

Dave

Re: ORION NEBULA at 1,000 frames of 1 second exposures

Posted: Thu Jan 28, 2021 4:45 pm
by oopfan
Interesting effect but eminently expected. It looks like a "paint-by-numbers" kit. I ran your equipment through my calculator and discovered that a one-second exposure is allowing in only about two photons per pixel in the mid-tones. Your sensor can handle a lot more.

Re: ORION NEBULA at 1,000 frames of 1 second exposures

Posted: Thu Jan 28, 2021 5:42 pm
by oopfan
Dave,

Yes but those images were captured with a 16-inch scope. You need a large aperture like that in order to Hoover-up enough photons in one second to mitigate the quantization seen in RBGDMD's image.

Brian

Re: ORION NEBULA at 1,000 frames of 1 second exposures

Posted: Fri Jan 29, 2021 3:46 am
by RickBG
Thanks for your comments.
I started somewhat late that evening when Orion Nebula was around 50 degrees latitude, causing a degradation of the image due to the balcony above. I live in a high-rise and when I photograph celestial objects on my balcony I am limited to 55 degrees or so in latitude. Using the Smart Histogram Brain, SharpCap Pro recommended little over three thousand frame at 1.1 seconds with a gain of 115 (the gain never changes no matter what object). I decided to stop live stacking at around 1,000 frames to avoid degradation of the finale image due to the above balcony issue and experiment to see how much data I can get out of it. I was surprised by the amount of data and decided to post it and to get some feedback. Since I'm using HyperStar focal reducer, it allows an 8" telescope to operate at a focal ratio of f/1.9, an incredible 28 times faster than the standard f/10 focal ratio, therefore no guiding necessary with extremely short exposures in the seconds not minutes.
That being said, having the three times the frames, as recommended by SharpCap, would certainly give more photons (data) to work with which increases detail...it is a matter of starting 40 minutes earlier. Looking forward to clear skies to post 3,000 frames to see the difference.
Thanks Dave for suggesting not to use my email as my user name. I'm thinking of changing it to "High-Rise Balcony Astronomer". Any thoughts?

Rick