Testing the Optolong L-eNhance OSC filter
Added December 6, 2021...
Optolong L-eNhance Spectrum Filter
This is from a test for a new filter, the Optolong L-eNhance, for the one-shot-color astronomy camera (ZWO ASI 071mc pro). I used these two nebulae, The Flaming star and the Horsehead as the test targets. This filter blocks out much of the green and yellow light which is in the middle of the visible light spectrum, which is responsible for most of the city light pollution interference.
The filter allows the red light on the lower end of the color spectrum, and blue light on the higher end of the visible light spectrum to pass through. Much of the light from nebulae is composed of this light. I am extremely pleased with the results of this filter.
![]() The Flaming Star Nebula |
![]() The Horsehead Nebula |
The Flaming Star Nebula
This is also known as IC 405. This is a case where the nebula came first, then the star. The bright star in the top center is known as AE Aurigae, which is part of the Auriga constellation. The star once belonged to the constellation of Orion within the Orion nebula and was part of what is known today as "The Trapezium", the four stars in the core of the nebula. About 2.7 million years ago, there was a stellar collision that bumped AE Auriga outward toward Auriga and the gaseous nebula. The star is burning at an incredible temperature of around 33,000°K (as compared to our sun's temperature of 5,778°K). This causes the star to appear bluish in color. The intense radiation given off by this star is causing the predominate hydrogen gasses in the nebula to glow in the red light. However, there are also hints of blue light which is a reflection from the star itself. The high speed velocity of this star is generating a violent bow shock which can be seen in this image below and to the right of the star. The star is about 1,320 light-years from earth and is about 23 times more massive than the sun.
The Horsehead Nebula
This nebula is about 1,375 light-years away and the horse's head is mainly a large cloud of interstellar dust obscuring the stars and nebulous gasses. The red color originates from hydrogen gas predominantly behind the nebula, ionized by the nearby bright star Sigma Orionis above the horse's head but not seen in this picture.
Equipment:
Telescope: Orion EON 130mm Triplet Refractor
Focal length: 910mm
Focal ratio: f/7
Camera: ZWO ASI 071 mc Pro
Filter: Optolong L-eNhance
Subframes: 300 seconds each
Camera Gain ... sensor temp: 250 ... -10°C
Mount: SkyWatcher EQ6-R Pro
Capture Software: N.I.N.A. Beta 2.007 nightly build
Guiding: PHD2
Stacking: Deep SkyStacker
Post-processing: PixInsight, Photoshop CC, and TOPAZ DeNoiseAI
Return to Pat Prokop's Heavenly Backyard Astronomy Page