# The Great Orion Nebula in Narrowband

- By: Astrofalls
- Date: 2019-11-12
- Classification: Photograph
- Museum: [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:The_Great_Orion_Nebula_in_Narrowband.jpg)
- Rights: [CC BY 4.0](https://creativecommons.org/licenses/by/4.0)
- Picture: https://invisiblenetwork.ai/thumbs/commons/thumb/e/e9/The_Great_Orion_Nebula_in_Narrowband.jpg/1920px-The_Great_Orion_Nebula_in_Narrowband.jpg
- Who can see it: Kids profiles and older (museums give no ratings; placed by Invisible Network from the museum's own words)

Here's an image I captured this last week of the Orion Nebula M42. Everyone who has done any astronomy is probably quite familiar with this star-forming region that sits in the middle of Orion's sword. The colors will not be familiar to most people, since the colors are falsely introduced by using narrowband filters. Red represents Sii emission, green/orange represents H-alpha emission, and blue represents Oiii emissions. The most interesting photographic thing about the Orion nebula is the immense brightness dynamic range in the area. The inner core, the trapezium, can be seen well in just small fifteen second exposures in most amateur telescopes, but the outer wispy clouds took me over 16hrs of exposure to properly show. This also presents a problem in how one can show both the dim and faint at the same time, which is actually quite easily solved in post-processing using HDR composition and adaptive histogram transformations.

Technical details: Equipment: Orion ed80tcf refractor SBIG ST8300m CCD Baader narrowband filters Paramount MyT equatorial mount Exposure: 28*1800" Ha 35*120" Ha 15*1800" Oiii 30*120" Oiii 10*1800" Sii

Total: 30hrs