Starless Rosette Nebula by Robert Huerbsch

Starless Rosette Nebula

June 15, 2018

Imaged over several nights in Jan and Feb, this false color image was composed from about 6 hours worth of:

Red = hydrogen alpha 6nm filter
Green = 30% Ha 70% OIII
Blue = Oyxgen III 6nm filter

Using a 730mm refracting telescope at F/5.6 with a small 4/3 monochrome CMOS camera cooled to -15c to reduce noise.

Panasonic MN34230ALJ 4/3 mono sensor
730mm · f/5.6 · 6 hours (120 x 3m)
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11 Comments

Bill Peppas's picture

Very good capture and processing Robert!
The starless process needs some refinements, you can do away with the few remaining stars ( which method are you using ? )

I have a version on my PC at home with the all the tiny stars removed, but when they get this small its a PITA and you loose additional detail. I remove them a variety of ways. Select > Color Range > Highlights and have a plug in that makes them smaller as well. Spot healing brush or even clone stamp can help as well.

Bill Peppas's picture

Try this to eliminate the rest.

Create a duplicate layer of the final layer ( merged ) of your photo.
Turn the duplicated layer into Grayscale/B&W.
Create a clipping mask on it.
Use the brush tool with its mode set to Lighten to paint only over the white spots.
Apply the mask, now use the clone stamp tool to fill in the tiny blank spots with the your false colors from the final image layer.

wow nice, thanks for the tip! I have a conference call starting soon but will def try that for sure.

I'm very good at the technical part of acquiring the data but still learning how to use Photoshop. Pix Insight is more commonly used but I wanted to learn Photoshop since I also have an interest in portrait and nightscape photography : )

Bill Peppas's picture

Photoshop is such a powerful tool, there's pretty much nothing it can't do ( except DSO stacking which is... possible but going to be done frustratingly manual most of the time and inconveniently ). There are plenty of ways to skin a cat they say, and in Photoshop, that is so true. Even the most experienced photoshopper learns something new every single day ( our only limit is our imagination on how we use its tools and settings ).

Hey Bill, found a terrific program for star removal, and it does it with the data in its raw/linear unstretched state! Will reprocess this when I get some time.

http://www.zipproth.com/Straton/

Ben Lockett's picture

Amazing depth, I don't know much about the complications of 'serious' Astro photography like this but you can't argue with the results, looks like something NASA would exhibit

thanks Ben! Its complicated to do because the Earth’s surface is spinning at 900mph while traveling at 3000mph through space. Your camera then has to track to within a pixel on a galaxy or nebula thousands of light years away…

This is why equatorial mounts (trackers) are needed. The good ones start at $6,000... but in the $1500-$2000 range is good enough for amateurs to start at longer focal lengths. The Star adventurers work well probably up to maybe 300mm which is actually great for a lot of large objects, usually nebulas and supernova remnants, with the exception of Andromeda

At first I thought it was a recreation of the cloud rendering of the titular character from "The Mummy". :-)

no worries, here is a wider field shot without star removal: https://www.astrobin.com/full/333380/B/

I like that much better. Thanks!