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iansmith

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About iansmith

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    Star Forming

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    Swindon
  1. Very nice image. Cheers, Ian.
  2. I prefer the smoother finish to the galaxies in B, the softer stars doesn’t bother me. But as Adam suggests, mask them off before applying Noise reduction or mask the rest off and use MT to tighten them up after noose reduction. Cheers, Ian
  3. Nope, I like imaging at 2800mm. It’s great for small targets like galaxies and planetary nebula I wouldn’t worry too much about the dust bunnies, I’ve seen much worse. Flat fielding will take care of it. Not sure what the dark spots are. Cheers, Ian
  4. One thought occurred to me on using longer integration times. The longer the integration, the smoother the target will be, but you will also get more faint stuff in the background, which is bound to be noisy. To me (looking on my phone) the main targets look great, it’s just the background where you have some noise. I don’t think there is much you can do about this other than targeted noise reduction on the background. Cheers, Ian.
  5. Yes, being able to come back to the same target night after night (or, with our weather, year after year ?), allows you to capture much more data on it. I get anywhere between 4 to 8 hours per filter. I’m inclined these days to go for 8 hours, which makes for a low output of images, but I think the extra SNR makes for a better picture. Also, going mono allows for the use of narrow band filters and that brings the option to image when the Moon is up (depending on the faintness of your target and it’s proximity to the Moon). Cheers, Ian.
  6. Not bad, but you need more data. Aim for as much as you have time/patience for. At least 4 hours to double the SNR. Cheers, Ian
  7. Also known as PK 204.1+4.7, Kohoutek 2-2 is a large, faint planetary nebula in the constellation of Monoceros. It is probably an old planetary nebula and appears embedded within a complex of even fainter nebulosity. Whether this is part of the original star’s red giant envelope or is something unrelated is unknown to me. According to The Simbad database, the planetary nebula has a diameter of 6.9’ and a distance of 2816 light years. There doesn’t appear to be much more information than that available about this particular planetary nebula. This image was taken over several nights between the beginning of February 2019 and mid-March 2019. The equipment used was a Celestron Edge HD11 telescope with Celestron f7 focal reducer, QSI6120 CCD camera (cooled to -25 C) and Astrodon 3nm Ha and O3 filters. The scope was guided with an ONAG and Ultrastar guide camera. The mount was a Mesu 200. The exposures were: 32x900s, binned 2x2, through the Ha filter and 32x900s, binned 2x2, through the O3 filter, giving a total of 16 hours. The image scale is 0.67” per pixel. After stacking the images in PixInsight I then separated the stars and nebula and processed them separately, before recombining to get the final colour image. I would have liked to replace the NB stars with RGB stars but ran out of time. For both stars and nebula the red channel is 100% Ha, the green channel is 50% Ha, 50% O3 and the blue channel is 100% O3. I hope you like it. Cheers, Ian
  8. Nice image. I had a similar plate solving issue once with Abell 5. The catalogues are not always perfect! Cheers, Ian
  9. Hello All, Below is an image of the planetary nebula NGC 7354. This little nebula is in Cepheus, about 4200 light years from us, and thought to be approx 0.5 light years in diameter. The image is a combination of narrow band for the nebula and broadband for the stars. Taken over several nights between October of last year and January this year it consists of: 16x900s 3nm Ha and 16x900s 3nm O3 subs for the nebula, mixed as red: 100% Ha; green: 50% Ha & 50% O3; blue 100% O3. The stars were captured using 15x120s subs through broadband red, green and blue filters. Equipment used: Celestron Edge HD 11 with 0.7 focal reducer, QSI 6120 CCD camera, ONAG and Ultrastar guide camera, mounted on a Mesu 200. Hope you like it, comments and criticisms welcome. Cheers, Ian
  10. Hello All, I've finally managed to finish processing my image of Abell 71, a faint planetary nebula in the constellation Cygnus. Filling most of the background is the emission nebula SH2-115. Because the O3 signal is quite weak compared to other planetary nebula, some consider this object to be an H2 region rather than a planetary nebula. I found the O3 signal to be weak, but not so faint it couldn't contribute to the final image. The image below is a combination of H alpha and O3 images for the nebulae and RGB images for the stars. The equipment used was: Edge HD 11 with 0.7 focal reducer QSI 6120 mono camera and 8 position filter wheel Mesu 200 mount ONAG with Ultrastar guide camera Exposure details are: Ha (Astrodon 3nm): 36x600s at 2x2 binning O3 (Astrodon 3nm): 36x600s at 2x2 binning R/G/B (Astrodon): 30x120s at 2x2 binning Taken between September and November 2018 from my backyard observatory in Swindon. This is the first imaging project for which I've used the QSI 6120, which I bought earlier this year. The purchase of the QSI was a cunning plan to get a low read noise CCD camera. The QSI already has a low read noise for a CCD, but by using the 2x2 binning I have (hopefully) reduced it further. The 2x2 binning mode also matches the sample rate to my usual seeing conditions, so this should produce a viable system with low read noise. According to the PixInsight script BasicCCDParameters. the read noise is 2.348e-. Although this is pretty low for a CCD I think I may need to use longer sub exposures to properly bury the read noise. In the unprocessed images SH2-115 is pretty noisy and I've used a fair bit of noise reduction to make it look smoother here, but I feel it could be better. Your comments on this aspect of the image would be appreciated. With so little imaging time available (thanks to the UK weather) I feel loath to spend it on experimentation, so for my next project I have gone for 15 minute subs to see what that gets me. The processing for this image was quite hard thanks to all that background nebulosity. My usual workflow is to remove/reduce the stars in the NB images, process them separately, and then combine to produce a colour starless narrow band image. Then I create a stars only image by processing the RGB images before combining the two for the final image. But with this project I kept getting nasty halos round the stars in my final image, as my star removal was too aggressive. Normally this wouldn't matter because there is rarely any background nebulosity to deal with, but not with this time. I have had to find another way to reduce the stars, which I hope as proven successful here. Please tell me if you think it hasn't worked, or could be done better. Anyway, after all that waffle, here is the final picture: Happy new year to you all, Ian
  11. Definitely needs more data to smooth out the noise, but you can already see plenty of structure in the nebula. Cheers, Ian
  12. Great image, I like the detail in the nebula and the nice star colours. Cheers, Ian
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