Swansea Astronomical Society Blog

A Seestar S50 was used in EQ mode to capture 1 hour 40 minutes of 10s exposures of the Swan nebula.

The data were stacked in PixInsight and futher processed in PixInsight, GraXpert and Gimp with G'MIC qt.

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HOO rendering

HOO RGB blend

SHO rendering

SHO-HOO rendering blend

Steve Wainwright and Nicola Mackin

posted by astroimager  # 10:10 PM 0 Comments

M17 in RGB/SHO & HOO: I added a further 3.25 hours of data (as much as a mid July night allows) to my M17 data set taken with my ASI 533MM Pro and Sky-Watcher Esprit 80 triplet refractor, to take the current total integration time to 6.25 hours worth. Using all of the available data I edited three separate versions; RGB, HOO and SHO and combined all three as a final blend of all the data.

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M17 in LRGB/SHO/HOO: I attempted to add some luminance data to my data set, however twilight thwarted its quality, so I was only able to use 15 minutes worth to add to the previous data set which is shown here as an uncropped edit of the full FOV this camera and scope arrangement allows. 

Chris Bowden

posted by astroimager  # 9:55 PM 0 Comments

NGC6960 Western Veil Nebula. 3.3 hours data using Seestar S50 in EQ and Mosaic mode. Stacked and processed in Pixinsight. The stacking has cropped some of the outer edge of the image, so unfortunately the nebula is not in the centre of the image as planned.

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 NGC6960 Western Veil Nebula.

Robert Elson

posted by astroimager  # 9:39 PM 0 Comments

The 94.7% Moon last night with a Seestar S50 in EQ mode. Best 60% of frames in a 6 minute RAW AVI were debayered and stacked with 1.5 drizzle in Autostakkert4. Wavelet sharpened in waveSharp and finished in the Gimp. 

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94.7% Moon

Steve Wainwright and Nicola Mackin

posted by astroimager  # 9:20 PM 0 Comments

 Seestar S50 in EQ mode

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M13

Steve Wainwright and Nicola Mackin

posted by astroimager  # 4:39 PM 0 Comments

M18 (The Black Swan Cluster): Just 6 minutes of RGB data in total were acquired on this sparsely populated and dim open cluster Messier object which lies in the constellation of Sagittarius. Just four 30 second subs per channel were taken with an ASI 533MM Pro camera and EFW using a Sky-Watcher Esprit 80ED triplet refractor fitted with a field flattener. Data were integrated and processed in Pixinsight along with an annotated version. M18 lies at a distance of 4,900 LY from Earth and is often overlooked due to it lying close to the more interesting targets of the Omega nebula and the small Sagittarius star cloud.

M23: Just 9 minutes of RGB data in total were acquired on this open cluster Messier object which lies in the NW corner of the constellation Sagittarius. Six 30 second subs per channel were taken with an ASI 533MM Pro camera and EFW using a Sky-Watcher Esprit 80ED triplet refractor fitted with a field flattener. Data were integrated and processed in Pixinsight along with an annotated version. M23 lies at a distance of 2,050 LY from Earth and contains around 400 small faint stars. The single brighter star is 6th magnitude which is unrelated to the cluster and appears as a foreground star in the same region of sky.

Albireo: Some 30 minutes of RGB data were acquired of this fine double star in the constellation of Cygnus located at the foot of the so called "Northern Cross". Six 60 second subs per channel were taken with an ASI 533MM Pro camera and EFW using a Sky-Watcher Esprit 80ED triplet refractor fitted with a field flattener. Data were integrated and processed in Pixinsight along with an annotated version and an additional image stepped down to reveal the double stars more clearly and colourfully.This must be one of the most popular objects for amateur astronomers and makes for a lovely sight in just about any scope due to the contrasting colours of the pair which are of magnitude 3 and 5. The brightest star is itself a binary but requires a much larger instrument than mine to resolve the pair.

Chris Bowden

posted by astroimager  # 12:59 PM 0 Comments

My image of M13 taken with my 80ED APO Skywatcher Refractor telescope with a field flattener. My 1300D DSLR Canon camera was mounted on the telescope.The telescope was mounted on my EQ5 Skywatcher GOTO mountt. Settings were 35s exposure, 800ISO. 230 images, 25 flat frames and 25 dark frames were captured. All were stacked in Sequator, edited in Siril, Photo Pea to reduce noise and Gimp 2.10. I used an intervalometer to control the camera and a Bahtinov mask to focus on a bright star. 

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M13

Chris Playle

posted by astroimager  # 6:17 PM 0 Comments

 Some recent noctilucent clouds as seen from my house in Gowerton!

posted by Gaynor Thomas  # 6:21 AM 0 Comments

IC1795 Fish Head Nebula. 4 hours data of 20 second subs using Seestar S50 in EQ mode. Processed in Pixinsight.

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IC1795 Fish Head Nebula

Robert Elson

posted by astroimager  # 5:11 PM 0 Comments

My wide field image of the Lagoon and Trifid Nebulae taken with my Rokinon 135MM prime lens at f/2 and my 1300D DLSR Canon camera and my Star Adventure 2i pro tracking mount. Settings were 45s and 800ISO. 120 subframes, 30 flat frames and 20 dark frames all stacked in Sequator and Edited in Siril, Starnet++, Gimp 2.10 and Photo pea for noise reduction. I used an intervalometer to control the camera and a Bahtiinov mask to focus on a bright star.

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Lagoon and Trifid Nebulae

 Chris Playle

posted by astroimager  # 5:17 AM 0 Comments

Just 62 minutes  of captured 10s frames were used to build the Mosaic. I used all of the time that this combination of nebulae was above my horizon before it set behind the mountain. Stacked in Siril using the DSA_Seestar_Mosaic_Preprocessing.ssf Siril script. Cropped, background extracted, denoised and part stretched in GraXpert, stars removed by Starnet++ sharpened and denoised in SetiAstro Suite. Separately sharpened in G'Mic Gimp plugin and finished in Gimp. The final canvass size is 1929 x 3502 compared with a normal Seestar S50 image of 1088 x 1920.

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Mosaic of The Lagoon and Trifid nebulae

HOO rendering using the PixInsight Toolbox script CreateHubblePaletteFromOSC then finishing in Gimp.

posted by astroimager  # 5:03 PM 0 Comments

51% Moon tonight. 153 bridge camera images precisely cropped and registered in Nicola's AstroCrop, stacked in Autostakkert!, wavelet sharpened in waveSharp and finished in the Gimp.

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51% Moon

Steve Wainwright and Nicola Mackin

posted by astroimager  # 11:32 PM 0 Comments

The Sun in white light today. 138 bridge camera (60x optical zoom)  images precisely cropped and registered in Nicola's AstroCrop, stacked in Autostakkert!, wavelet sharpened in waveSharp and finished in the Gimp.

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The Sun in white

Steve Wainwright and Nicola Mackin

posted by astroimager  # 7:42 PM 0 Comments

This example is based on an imaging session with a Seestar S50 in Equatorial mode and capturing 10s exposures. The total capture time was 102 minutes.

The Seestar was fitted with a long dewshield that not only acts as a dewshield but also quite effectively cuts out light from the side from streetlights impinging on the objective and causing gradients across the image. The dewshield does not introduce any vignetting. An external powerpack was attached to the Seestar to enable it to maintain its charge and also effectively run its anti-dew heater.

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The equipment

The Seestar was controlled by a 10.1” Android tablet, also connected to a smaller external power bank to keep it charged during the imaging session

The Seestar was set to place a watermark at the bottom of the image that is saved at the end of the session or an image saved at any stage during capture. If the Seestar is set not to include a watermark then the whole of the captured live-stacked image would be available for the following procedures without cropping.

The saved, fairly noisy image as saved to the tablet

The Seestar app has an AI denoise function that can be applied to the image on the screen at any time and then saved. This was done a minute before the imaging session was terminated after 102 minutes.

The AI denoising did quite a good job and the image is much improved over the normal saved image. However the image still needs stretching to show the nebula better.

Here we have used the standard Google images editor that is standard in Android, and experimented with the functions to produce a satisfactory enhancement.

At this stage, it would be possible and acceptable to consider the process completed, as we have a pleasant, and in this case watermarked image.

The image could, however, benefit from the removal of the stars and their replacement with less prominence, as the stretching increased their prominence, which could distract from the nebula.

In order to do this, we first need to crop the image to get rid of the watermarked region. As we indicated earlier, this would be unnecessary if the Seestar had been set not to watermark the image. Cropping can easily be done in the Gimp image processing software on a computer.

The cropped image

Whilst in the Gimp, the image should be converted to 16bit integer and Linear light and exported as a tif, as this is needed for the star-removal program Starnet++.

posted by astroimager  # 3:57 PM 0 Comments

Chinese Dragon nebula. 101 minutes worth of 10s exposures with a Seestar S50. Stacked and SPCC in PixInsight. Further processing with GraXpert, SetiAstro Suite with Starnet++ and Gimp 3.0

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Chinese Dragon nebula

Steve Wainwright and Nicola Mackin

posted by astroimager  # 4:38 PM 0 Comments

 A Panasonic Lumix DMC-FZ72 60x Optical Zoom Bridge camera mounted on a static tripod was used to capture 150 images of the waxing crescent Moon. The best 95% of the images were stacked in Autostakkert!4, wavelet processed in waveSharp and finished in Gimp 3.

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22.5% waxing, crescent Moon

Steve Wainwright

posted by astroimager  # 2:00 AM 0 Comments

A Panasonic Lumix DMC-FZ72 Bridge camera was used to capture images of noctilucent clouds at the Head of the Avan Valley.

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Noctilucent Clouds

posted by astroimager  # 1:53 AM 0 Comments