Science, Astronomy, & Engineering projects
Object
IC 1848, SH2-199 The Soul Nebula
Description
HOO Composition
The Soul Nebula is located right next the Heart Nebula and occupies a large field of view. Best photographed with a wide field lens or telescope. I shot this with a 200mm Nikon lens.
Camera
Mount
Guide Scope
Guide Camera
Filters
Integration Time
300S sub frames for a total integration time of 385Min or 6.4Hrs
Aquisition Date
2/8/2023
Object
IC 1805 SH2-190
Description
Also known as the Running Dog Nebula.
HSO Composition
Camera
Mount
Filters
Integration Time
3 Hours with 60S sub frames
Aquisition Date
1/21/2023
I recently purchased the ZWO 1.25″ narrowband filter set. The set include 3 filters H-alpha, S-II, and O3.
Narrowband filters are a great way to battle light pollution when photographing emission nebula. I live in a Bortle 8-9 area so for me narrow band is a must have. Even in light polluted skies, you can achieve highly detailed color images with a monochrome camera.
Thickness – 2mm (glass)
Cost – $369 as of post date
Light Pass – up to 90% (see chart) The manufacturer says “up to 80%” but if you look at the chart, it clearly say 90%. I suspect it’s just a typo on their site since the chart is more reliable.
Band Pass – 7 +/- .5nm
Wavelength
H-alpha – 656nm
S-II – 672nm
O3 – 500nm
Mounted – yes (standard 1.25″ filter thread male)
The filters are pre mounted onto standard 1.25″ male filter threads. I have used them individually and also with the ZWO Filter wheel. All you have to do is to screw them into the filter holder.
The following images were taken in my back yard using all three of these filters.
Camera – ZWO 1178mm
Mount – Skywatcher EQM-35 Pro
Guide Software – AsiAir Plus
Guide Scope – SVBony SV165
Agena AstroProducts has a rating of 4.3 stars with 6 reviews.
High Point Scientific has a 5 star rating with 2 reviews.
Most of the feedback posted from customers has been positive. The 4 star ratings mention difficulty focusing and not fitting the filter wheel. For me they fit perfectly so I cannot replicate any issue that the customer mentioned. As far as focuing goes, I can attest that it is more difficult to focus with the filters. The issue is that there is a significant reduction in the amount of light passed to the camera. To overcome this, I use a 15 to 30 second exposure time in the focus and preview mode. With the addition of a Bahtinov mask, I can use the preview function with long exposure to fine tune the focus.
As I just mentioned, focusing is a challenge. Here is how I get to focus fast with my setup. I use a filter wheel with my kit. I bought a cheap CLS filter and added it to the wheel. To get close but not yet perfect, I just switch to the CLS filter and increase my exposure time to 2 to 5 seconds. This get’s me very close to what the narrow band filter need to be at.
After this step, I switch to the filter I intend to use and use the preview mode with 30 seconds. With the mask, I can achieve perfect focus this way.
There was a recent break in the weeks of rainy weather. I jumped on this opportunity to capture one of my most favorite nebula – IC434 also known as the Horsehead Nebula.
Since I was using a wide field lens of 200mm, I added the Flame Nebula to the composition. The Flame Nebula is an emission nebula which is unlike the Horsehead Nebula. The Horsehead is a dark nebula that does not emit much of it’s own light. Instead, this nebula is illuminated from behind where there is a type HII emission nebula. This arrangement creates a mystical looking scene with horse head appearing from the shadows.
This region of the sky is located near the infamous Orion Nebula.
This region of space has significant amounts of hydrogen and S-II gases with some Oxygen 3. I captured all three of these with narrowband filters that I purchased here.
Using these filters allowed me to get strong data even in my Bortle 8 light polluted back yard.
I just love Hydrogen Alpha monochrome images. They have so much detail and show a great deal of the emission.
There are many color palettes to choose from when creating images from monochrome data. I get the best results when I use Hydrogen-alpha as Red. For the Blue and Green channels, it depends on what the next strongest signal I have obtained. Since this image has so much Sulfur, I used the S-II for both the Blue and the Green channels. I have found that also adding a luminance layer greatly increases the color and detail. For this image I used the H-alpha as the luminance layer. All of this data was processed using Siril, the free open source astrophotography imaging processing program.
