Tag Archives: Baader

The source to the halo around bright stars

When I moved to the Sky-Watcher Quattro telescope I noticed some bizzare halo’s around bright stars in my images, this was evident in both my Atik 383L+ CCD Camera as well as my QHY183M ColdMOS Camera, if you browse my galleries you will see what I mean, and it was more noticable in my Narrowband images. Below is one of my recent images where you can see the halo around Magnitude 3.9 star 15 Mon in the Christmas Tree Cluster / NGC2264.

I contacted Baader back in February 2019 since all of my filters were Baader, and I noticed that the Halo was present in all of my filters but significantly less in Red, but more prevalent in Narrowband filters, so the logical cause would be the filters. Baader immediately dismissed this to be the fault of their filters and suggested that my Coma Corrector be the root cause.

Not convinced that the Coma Corrector was causing the issue, I did some research online and came across a brilliant page on the Astronomik website where they claim to have resolved the majority of the Halo issue, and after reading the following line from the page I was convinced the filters were my issue:

In recent years very fast optical systems have become popular for imaging. The energy in a filter induced halo grows exponentially as the f-ratio decreases. Additional to this, the smaller the FWHM band pass of the filter, the stronger the halo.

The above line described my issue perfectly so I mentioned this to Baader who again dismissed the possibility of it being their filters and again put the blame firmly to my optical train. Again not happy, I contacted Astronomik and Eric emailed me back very promptly and offered to send me out one of their 6nm Ha filters to test. A few days ago the filter arrived and I was able to perform some testing against the Baader filter also for comparison on the same star.

Since the star in my image above was of magnitude 3.9, I wanted to find something similar, so I found star Alhaud VI and proceeded to obtain 15x300S Exposures for each filter, and here are the results:

Astronomik 6nm HA filter, 15x300S with Darks and Flats applied
Baader 7nm Ha filter, 15x300S with Darks and Flats applied

So as you can see the Baader filter shows a high amount of Halo around the bright star and the Astronomik filter does not, now if this was something to do with the rest of the optical train there would be evidence in the Astronomik filter also.

Now I agree there will be some reflection in the optical train, all that glass in the coma corrector, the glass on the camera etc, so I thought I would have a look at both images in a bit more detail, zoomed in on the stars there is what appears to be a slight halo in the same place on both images:

Astronomik 6nm Ha Filter
Baader 7nm Ha Filter

So both filters show the Inner Halo which in my opinion would not be visible in an image, but again clearly the Baader filter has some reflection issues happening as you can clearly see two additional Halos. The interesting thing about all three Halos is that the central one visible in both filters has no relationship to the distances between the other two in the Baader, however the two outer Halos on the baader are the same distance apart as the middle halo is from the star, so clearly this is some sort of reflection.

Conclusion:
Astronomik have done a fantastic job at eliminating Halo artifacts around bright stars, clearly the Baader filters are causing major Halo artifacts because if this was the optical train then it would be evident in the Astronimik filters also, I suspect that the Baader filters are not optimised for faster focal ratio imaging systems. I have provided this information to Baader and await a response from them.

Good job Astronomik Filters

IC5146 / Cocoon Nebula in HaRGB

This is my first time ever imaging this target, and like the Crescent Nebula and Pelican Nebula I am limited to a 2.5 hour window per night to acquire data due to trees / house getting in the way, luckily I managed to get a lot of Ha data on this subject to blend this into the RGB image which smoothed out the lack of data for RGB somewhat, I would have liked to have got more RGB Data and I may re-image this with longer exposures on RGB next time also

Cocoon Nebula in HaRGB
Cocoon Nebula in HaRGB with PIxInsight 2x Drizzle

Image Details:
56x150S in R
56x150S in G
66x150S in B
101x300S in Ha

Acquisition Dates: Sept. 25, 2018, Sept. 27, 2018, Sept. 29, 2018, Oct. 20, 2018, Oct. 22, 2018, Oct. 26, 2018, Oct. 28, 2018, Oct. 29, 2018, Nov. 14, 2018, Nov. 17, 2018, Nov. 18, 2018, Nov. 30, 2018, Dec. 7, 2018, Dec. 9, 2018, Dec. 12, 2018, Dec. 13, 2018, Dec. 27, 2018, Jan. 4, 2019

All frames had 101 Darks and Flats applied, the Ha layer was blended using the new NBRGB Script in PixInsight 1.8.6, the more zoomed in picture is of the same data but with a 2x drizzle applied then cropped

Equipment Details:
Imaging Camera: Qhyccd 183M Mono ColdMOS Camera at -20C
Imaging Scope: Sky-Watcher Quattro 8″ F4 Imaging Newtonian
Guide Camera: Qhyccd QHY5L-II
Guide Scope: Sky-Watcher Finder Scope
Mount: Sky-Watcher EQ8 Pro
Focuser: Primalucelab ROBO Focuser
FIlterwheel: Starlight Xpress Ltd 7x36mm EFW
Filters: Baader Planetarium RGB and Ha
Power and USB Control: Pegasus Astro USB Ultimate Hub Pro
Acquisition Software: Main-Sequence Software Inc. Sequence Generator Pro
Processing Software: PixInsight 1.8.6

Flickr Link: https://www.flickr.com/…/465843…/in/album-72157688487449350/

AstroBin Link: https://www.astrobin.com/384658/

NGC6888 – Crescent Nebula in SHO Narrowband

This object is a little tricker for me since I only have a 3-3.5 hour window per evening due to trees and the house blocking my view, this is also the first image that I used the drizzle function within PixInsight to be able to provide a detailed up close version of the image, I was very happy to have captured the brown “Globules” within the nebula to

Crescent Nebula in SHO Narrowband
Same object but with a 2x drizzle function in PixInsight applied

Image Details:
Red Channel – SII Data – 89x300S
Green Channel – Ha Data – 64x300S
Blue Channel – OIII Data – 109x300S

101 Darks, Flats and BIAS Frames used 

Equipment Used:-
Imaging Camera: QHY183M Mono ColdMOS Camera at -20C
Imaging Scope: Skywatcher Quattro 8″ F4 Newtonian
Guide Scope: Skywatcher Finder Scope
Guide Camera: QHY5L-II
Mount: Skywatcher EQ8 Pro GEM Mount
Focuser: PrimaluceLabs ROBO Focuser
Filterwheel: StarlightXpress 7x36mm EFW
Filters: Baader 7nm Ha, SII and OIII
Acquision Software: Main Sequence Software Sequence Generator Pro
Processing Software: Pixinsight 1.8.5

M51 – Whirlpool Galaxy in LRGB

Another Image that I have previously imaged with the Atik Camera, again demonstrating a different resolution obviously showing off a bit more detail, here’s the image previously:

Equipment Used:
Imaging Scope: Sky-Watcher Quattro 8″ F4 Imaging Newtonian
Imaging Camera: Qhyccd 183M 20mpx ColdMOS Camera at -20C
Guide Scope: Sky-Watcher Finder Scope
Guide Camera: Qhyccd QHY5L-II
Mount: Sky-Watcher EQ8-Pro GEM Goto Mount
Filterwheel: Starlight Xpress Ltd 7x36mm EFW
Filters: Baader Planetarium 36mm LRGB Filters

Software:
Image Acquisition: Main Sequence Software SGPro 3
Guiding: PHD2
Image Processing: PixInsight

Target Details:
Name: M51 / NGC5194 / Whirlpool Galaxy
Constellation:Canes Venatici
RA: 13h 29m 53.00s
Dec: 47° 11′ 51.10″
Distance from Earth: >23 Million Light Years

Image Details:
Luminance: 101×150 Second Exposures
Red: 85×150 Second Exposures
Green: 85×150 Second Exposures
Blue: 85×150 Second Exposures
Total Exposure Time: 14.83 Hours

Acquisition Dates: 6 Apr 2018, 19/20/21 Apr 2018, 5/6/7/8/9 May 2018

 

 

 

Leo Triplet in LRGB

This is not the first time I have imaged this trio of trespassers, I have imaged them before on the same scope but with my previous Atik 383L+ CCD Imager, so again similar to M81 and M82, you can clearly see the difference in resolution the new camera offers, here’s the previous image taken from my previous post here:

Equipment Used:
Imaging Scope: Sky-Watcher Quattro 8″ F4 Imaging Newtonian
Imaging Camera: Qhyccd 183M 20mpx ColdMOS Camera at -20C
Guide Scope: Sky-Watcher Finder Scope
Guide Camera: Qhyccd QHY5L-II
Mount: Sky-Watcher EQ8-Pro GEM Goto Mount
Filterwheel: Starlight Xpress Ltd 7x36mm EFW
Filters: Baader Planetarium 36mm LRGB Filters

Software:
Image Acquisition: Main Sequence Software SGPro 3
Guiding: PHD2
Image Processing: PixInsight

Image Details:
Luminance: 101×150 Second Exposures
Red: 101×150 Second Exposures
Green: 101×150 Second Exposures
Blue: 101×150 Second Exposures
Acquisition Dates: 18/19/20/21 Apr 2018,  4/5/6/7/8/9 May 2018

Total Exposure Time: 16.83 Hours

Target Details: Leo Triplet
Constellation: Leo
RA: 11h 19m 36.15s
Dec: 13° 17′ 2.90″
Distance from Earth: 35 Million Light Years
Galaxies: M65 (Top Right), M66 (Bottom Right) and NGC3628 (Bottom Left) also known as The Hamburger Galaxy or Sarah’s Galaxy

M97 / NGC3587 – Owl Nebula in LHaRGB

I have imaged this before in the same frame as the Surfboard Galaxy, however the 0.62 Arcseconds Per Pixel the Qhyccd 183M gives me on my Sky-Watcher Quattro 8″ F4 gives me a much higher resolution image, so here it is, the Owl Nebula in the constellation of Ursa Major at a distance of 2030 Light years from Earth

Gear:
Imaging Scope: Sky-Watcher Quattro 8″ F4 Imaging Newtonian
Imaging Camera: Qhyccd 183M 20mpx ColdMOS Camera at -20C and DSO Gain
Mount: Sky-Watcher EQ8 Pro
Guide Camera: Qhyccd QHY5L-II Mono
Guide Scope: Sky-Watcher 50×90 Finder Scope
Filter Wheel: Starlight Xpress Ltd 7x36mm EFW
Filters: Baader Planetarium 36mm RGB
Coma Corrector: Sky-Watcher Aplanatic Coma Corrector
Image Acquisition: Main Sequence Software SGPro
Image Processing: PixInsight

Image Details:
Target: M97/NGC3587 – Owl Nebula
Constelation: Ursa Major
Red: 27x300S
Green: 27x300S
Blue: 27x300S
Ha: 25x600S
Darks: 51x300S
Flats: 101
Bias: 251 converted to SuperBIAS and deducted from Flats
Imaging Dates: Feb. 12, 2018,  Feb. 16, 2018,  Feb. 24, 2018,  Feb. 25, 2018

PixInsight Image processing workflow:
1. Calibrated against darks and Bias Subtracted Flats
2. Star Alignment for all RGB and Ha Frames
3. Least noise frame from each colour chosen as Normalization Frame and Dynamic Background Extraction Performed
4. Normalization of all frames
5. Stacking of frames and generation of drizle data (for larger quality image in future)
6. Performed LinearFit using Red stacked image as reference for RGB Frames
7. Performed DynamicCrop on all channels and Ha
8. Performed MultiMedianTransformation to reduce background noise
9. Performed SCNR to remove excessive green in image
10. Stretched the image using HistogramTransformation
11. Performed an Unsharp Mask on RGB and HA Data
12. Performed an ATWT on the Background
11. Merged the Ha Data using the HaRVB-AIP Script in PixInsight
12. Performed a CurvesTransformation to bring out the star colour

IC434 – Horsehead Nebula in LRGB

My first RGB Image from the Qhyccd 183M 20mpx Back Illuminated ColdMOS Camera, so here’s what I hope is one of many images taken with this awesome camera

Gear:
Imaging Scope: Sky-Watcher Quattro 8″ F4 Imaging Newtonian
Imaging Camera: Qhyccd 183M 20mpx ColdMOS Camera at -20C and DSO Gain
Mount: Sky-Watcher EQ8 Pro
Guide Camera: Qhyccd QHY5L-II Mono
Guide Scope: Sky-Watcher 50×90 Finder Scope
Filter Wheel: Starlight Xpress Ltd 7x36mm EFW
Filters: Baader Planetarium 36mm RGB
Coma Corrector: Sky-Watcher Aplanatic Coma Corrector
Image Acquisition: Main Sequence Software SGPro
Image Processing: PixInsight

Image Details:
Target: IC434 – Horsehead Nebula
Constelation: Orion
Red: 19x300S
Green: 19x300S
Blue: 19x300S
Darks: 51x300S
Flats: 101
Bias: 251 converted to SuperBIAS and deducted from Flats

Data acquired on: Feb. 9, 2018,  Feb. 11, 2018,  Feb. 15, 2018

PixInsight Image processing workflow:
1. Calibrated against darks and Bias Subtracted Flats
2. Star Alignment
3. Least noise frame from each colour chosen as Normalization Frame and Dynamic Background Extraction Performed
4. Normalization of all frames
5. Stacking of frames and generation of drizle data (for larger quality image in future)
6. Performed LinearFit using Red stacked image as reference
7. Performed MultiMedianTransformation to reduce background noise
8. Performed SCNR to remove excessive green in image
9. Stretched the image using HistogramTransformation
10. Performed a CurvesTransformation to bring out the star colour

Right now I have not performed any Sharpening of the image, nor have I added the Ha data to this image, I’ll post an updated image when I get round to doing that

QHY183M Review – Part 2

As promised, now that I have done some imaging with my new QHYCCD 183M Mono ColdMOS Back Illuminated camera here’s the second part of my review on the camera.

Pixel size:- The pixel size on the 183M is 2.4um which I absolutely love, on my Sky-Watcher 8 Inch Quattro F4 the camera gives me a field of view of 0.62 Arcseconds/Pixel, which is a fantastic resolution, I remember when I had my Atik 383L+ and my Astro-Tech AT8RC F8, that offered me a resolution of around 0.63 Arcseconds/Pixel, so I am now imaging at almost the same field of view but at F4 and at 20mpx, but let’s just put that into comparison on the same scope, the first image below is IC434 taken with the Atik 383L+ on the Quattro, and the second image below is taken with the QHY183M on the same telescope, you can see what impact it has on the field of view:

FOV on Atik 383L+ with 8″ Quattro F4

FOV on QHY183M with 8″ Quattro F4

As you can see from the above two images the difference in the field of view due to the chip size.

Camera Sensitivity:- Since moving to the QHY183M I have had to make changes to how I image, having owned the Atik 383L+ for a good few years, I got used to imaging with it, so when I moved to the QHY183M I suddenly noticed that this camera was quite a bit more sensitive, the first image above consists of 300 second frames for the LRGB whereas the second image consists of just 150 second frames, yes 150 second frames!!!

When I first started imaging M81/M82 with the QHY183M, I immediately started with 300 Second frames, I ended up with the same amount of 300 second frames that I had with the Atik 383L+ but I just could not process it, after further analysis I noticed then that the lights were severely clipped, to put this into perspective, below is the Sequence Generator Pro Histogram for both the 300 second exposure (left) and the 150 second exposure (right)

As you can see the histogram on the left for the 300 second exposure is severly clipped on the right side of the histogram indicating that the exposure was too long, the histogram on the right for the 150 second exposure is a lot better, there is still some slight clipping happening but this was a luminance frame, this clearly indicates that the 183M is much more sensitive than my previous CCD imager.

The following two images were produced with the 183M, firstly IC434 consists of 19×300 Second Exposures in RGB and the Second Image of The Owl Nebula consists of 27×300 second exposures in RGB + 25x600S in Ha

Software Integration:- As you probably know already, I use Sequence Generator Pro for my image acquisition and the integration with the camera has been pretty seemless, the ASCOM platform driver works pretty well, and I have the camera set to the default gain and offset setting that QHY have provided which is 16 of Gain and 76 for offset:

UV/IR Sensitivity:- I have read online that the 183M is a little bit sensitive to UV/IR Light, so I asked the guys at QHYCCD about this abd they informed be that the window on the senor is straight clear glass, so it also lets in UV/IR Light, which for me is not an issue as all of my Baader filters are UV/IR Blocked anyway, but it is something to consider if I ever change filters.

Conclusion
The camera has performed way beyond my expectations, had to change some of my approaches to image acquisition but that was to be expected, I am extremely happy with the camera and look forward to getting more data to compliment the Luminance for M81/M82 in the not so distant future.

If you are considering the QHY183M as an imaging camera, and would like to discuss, then feel free to reach out to me.

Clear Skies

M97 and M108 – Owl Nebula and Surfboard Galaxy in LRGB

M97 and M108

The Owl Nebula (also known as Messier 97, M97 or NGC 3587) is a planetary nebula located approximately 2,030 light years away in the constellation Ursa Major.  It was discovered by French astronomer Pierre Méchain on February 16, 1781

Messier 108 (also known as NGC 3556) is a barred spiral galaxy in the constellation Ursa Major. It was discovered by Pierre Méchain in 1781 or 1782. From the perspective of the Earth, this galaxy is seen almost edge-on.

The image consists of the following
23x180S – Red
23x180S – Green
23x180S – Blue
25x180S – Luminance

25 Darks, 25 Flats and 25 BIAS frames have also been applied

Equipment Used:-
Imaging Scope: Sky-Watcher Quattro Series 8-CF F4 Imaging Newtonian
Flattener: Sky-Watcher Aplanatic Coma Corrector
Imaging Camera: Atik Cameras 383L+ Mono CCD -20C
Guide Scope: Celestron Telescopes C80ED Reftractor
Guide Camera: Qhyccd QHY5L-II
Mount: Sky-Watcher EQ8 Pro
Filterwheel: Starlight Xpress Ltd 7x36mm EFW
Filters: Baader Planetarium 36mm Unmounted LRGB
Image Capture: Main Sequence Software SGPro
Image Stacking: Maxim-DL
Image Processing: PixInsight

Leo Triplet of Galaxies

Leo Triplet In LRGB (above) and LRGB+HA (below)

The Leo Triplet consists of three galaxies at a distance of around 35 million light years, M65 (top right), M66 (bottom right) and NGC3628 (left).  I have always aimed at imaging the triplet since I started imaging but never got around to it.

M65 (NGC 3623) and M66 (NGC 3627) are classed as intermiediate spiral galaxies and NGC3628 is also known as the Hamburger Galaxy or Sarah’s Galaxy and is classed as an Unbarred Spiral Galaxy.

The image consists of:-
29x300S of Luminance
14x300S Red, Green and Blue
15x600S of 7nm HA in the LRGB+HA Image
25 Darks and flats subtracted from all frames

Equipment Details:
Imaging Telescope: Sky-Watcher Quattro 8-CF F4 Imaging Newtonian
Imaging Camera: Atik Cameras 383L+ Mono CCD
Coma Corrector: Sky-Watcher Aplanatic Coma Corrector
Guide Camera: Qhyccd QHY5L-II
Guide Scoope: Celestron Telescopes C80ED Refractor
Mount: Sky-Watcher EQ8 Pro
Filter Wheel: Starlight Xpress Ltd 7x36mm USB EFW
Filters: Baader Planetarium LRGB + 7NM HA

Image Aquisition: Main Sequence Software SGPro
Image Pre-Processing and STacking: Maxim-DL
Post Processing: PixInsight

In my opinion, there’s only a subtle difference between the LRGB and LRGBHA images, personally I preffer the LRGB Version, the data was captured over multiple nights since the beginning of 2017 but in total gives 5.91 Hours on the LRGB Image and 8.41 Hours for the LRGB+HA Image