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Bright Nebula in Ara ( NGC 6188 ) source: 500px.com/mikeoday
MikeODay posted a gallery image in Member's Album
From the album: Mike's Images
Bright Nebula NGC 6188 and open cluster NGC 6193 in Ara by Mike O'Day Magnitude +5.19, RA 16h 41m 42s, Dec -48deg 48' 46" Approx. 3800 light years away Skywatcher Quattro 10" f4 Newtonian. Skywatcher AZ Eq6 GT Mount (on concrete pier) Orion 80mm f5 guide scope and auto guider - PHD2. Baader MPCC Mark 3 Coma Corrector, UHC-S 'nebula' filter. Nikon D5300 (unmodified). Field of view (deg) ~ 1.35 x 0.90. UHC-S - 32 x 180 sec ISO800 (14bit NEF, Long Exp. NR on). Pixinsight and photoshop 7 July 15 (processed 29 August 15) source: photo.net/photos/MikeODay 500px.com/mikeoday© Copyright Mike O'Day 2015 - all rights reserved
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From the album: Mike's Images
NGC 6357 in Scorpius Skywatcher Quattro 10" f4 Newtonian. Skywatcher AZ Eq6 GT Mount Orion 80mm f5 guide scope and auto guider - PHD2. Baader MPCC Mark 3 Coma Corrector, UHC-S 'nebula' filter. Nikon D5300 (unmodified). Field of view (deg) ~ 1.35 x 0.90. UHC-S - 100 x 100 sec ISO800 (14bit NEF, Long Exp. NR on). Pixinsight and photoshop© Copyright Mike O'Day 2015 - all rights reserved
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From the album: Mike's Images
Blue Moon - 31st July 2015 Skywatcher Quattro 10" f4 Newtonian ("full moon" dust cap in place). Skywatcher AZ Eq6 GT Mount Orion 80mm f5 guide scope and auto guider - PHD2. Baader MPCC Mark 3 Coma Corrector, UHC-S 'nebula' filter. Nikon D5300 (unmodified). ISO200, 14bit NEF, Long Exp. NR off. 487 sub exposures @ 1/50th Subs taken over 45min period covering Full Moon @ 10:42 UT (8.42pm local time). Processed using Registax and Photoshop© Copyright Mike O'Day 2015 - all rights reserved
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From the album: Mike's Images
NGC 2070 Tarantula Nebula Skywatcher Quattro 10" f4 Newtonian. Skywatcher AZ Eq6 GT Mount. Baader MPCC Mark 3 Coma Corrector. Nikon D300 (unmodified). 80 x 30 sec ISO800 unguided. 24 Apr 14 Reprocessed 9 August 15© Copyright Mike O'Day 2015 - all rights reserved
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From the album: Mike's Images
Eagle Nebula - Messier 16 Skywatcher Quattro 10" f4 Newtonian. Skywatcher AZ Eq6 GT Mount Orion 80mm f5 guide scope and auto guider - PHD2. Baader MPCC Mark 3 Coma Corrector, UHC-S 'nebula' filter. Nikon D5300 (unmodified). Field of view (deg) ~ 1.35 x 0.90. ISO800, 14bit NEF, Long Exp. NR on. 33 x 180sec (1/3 before & 2/3 after zenith) New Moon, 4deg C, 75%RH, moderate LP. PixInsight© Copyright Mike O'Day 2015 - all rights reserved
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From the album: Mike's Images
Eagle Nebula - Messier 16 Skywatcher Quattro 10" f4 Newtonian. Skywatcher AZ Eq6 GT Mount Orion 80mm f5 guide scope and auto guider - PHD2. Baader MPCC Mark 3 Coma Corrector, UHC-S 'nebula' filter. Nikon D5300 (unmodified). Field of view (deg) ~ 1.35 x 0.90. ISO800, 14bit NEF, Long Exp. NR on. 33 x 180sec (1/3 before & 2/3 after zenith) New Moon, 4deg C, 75%RH, moderate LP. PixInsight© Copyright Mike O'Day 2015 - all rights reserved
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From the album: Mike's Images
Eagle Nebula - Messier 16 Skywatcher Quattro 10" f4 Newtonian. Skywatcher AZ Eq6 GT Mount Orion 80mm f5 guide scope and auto guider - PHD2. Baader MPCC Mark 3 Coma Corrector, UHC-S 'nebula' filter. Nikon D5300 (unmodified). Field of view (deg) ~ 1.35 x 0.90. ISO800, 14bit NEF, Long Exp. NR on. 33 x 180sec (1/3 before & 2/3 after zenith) New Moon, 4deg C, 75%RH, moderate LP. PixInsight© Copyright Mike O'Day 2015 - all rights reserved
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From the album: Mike's Images
Eagle Nebula - Messier 16 Skywatcher Quattro 10" f4 Newtonian. Skywatcher AZ Eq6 GT Mount Orion 80mm f5 guide scope and auto guider - PHD2. Baader MPCC Mark 3 Coma Corrector, UHC-S 'nebula' filter. Nikon D5300 (unmodified). Field of view (deg) ~ 1.35 x 0.90. ISO800, 14bit NEF, Long Exp. NR on. 33 x 180sec (1/3 before & 2/3 after zenith) New Moon, 4deg C, 75%RH, moderate LP. PixInsight© Copyright Mike O'Day 2015 - all rights reserved
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From the album: Mike's Images
Orion Nebula Skywatcher Quattro 10" f4 Newtonian. Skywatcher AZ Eq6 GT Mount Orion 80mm f5 guide scope and auto guider - PHD2. Baader MPCC Mark 3 Coma Corrector, UHC-S 'nebula' filter. Nikon D5300 (unmodified). Field of view (deg) ~ 1.35 x 0.90. ISO800, JPEG Fine, Long Exp. NR on. HDR processed in PixInsight - 20x120sec, - 20x30sec, - 20x 8sec, - 12x4sec. Individual groups aligned and integrated. Then four integrated images aligned and HDR combined. 17 January 2015 - reprocessed 25 Apr 2015© Copyright Mike O'Day 2015 - all rights reserved
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From the album: Mike's Images
NGC 3372 Eta Carinae Nebula (RA 10:44:22.47 - Dec -59 56' 36.5"). Skywatcher Quattro 10" f4 Newtonian. Skywatcher AZ Eq6 GT (on Pier) Orion auto guider - PHD2. Baader MPCC Mark 3 Coma Corrector, UHC-S (Nebula) filter, Nikon D5300 (unmodified), Long Exp Noise Reduction on, 12bit NEF, UHC-S 15 x 120 sec ISO800. PixInsight & Photoshop 19 March 15© Copyright Mike O'Day 2015 - all rights reserved
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From the album: Mike's Images
IC2948 Running Chicken Nebula in Centaurus ( bright star is Lambda Cenauri) (RA 11h 39.6m - Dec -63deg 37.2'). Skywatcher Quattro 10" f4 Newtonian. Skywatcher AZ Eq6 GT (on Pier) Orion auto guider - PHD2 (RA only - Dec ungiuded). Baader MPCC Mark 3 Coma Corrector, UHC-S (Nebula) filter, Nikon D5300 (unmodified), Long Exp Noise Reduction on, 14bit NEF, 13 x 300 sec ISO 200. PixInsight & Photoshop 28 March 15© Copyright Mike O'Day 2015 - all rights reserved
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d7500 D7500 has high thermal pattern noise
MikeODay posted a blog entry in Nikon D7500 DSLR for Astrophotography
In an earlier post I examined the noise in single dark frames over a range of exposure times. My conclusion was that the Nikon D7500 was a lower noise camera than the D5300. This was also backed up by an examination of master bias frames that again strongly favoured the D7500. However ... The first image I attempted to produce with the D7500 exhibited very strong streaks in the noise. I had been in the habit of not using dark subtraction with the D5300 as it has very low thermal pattern noise. Accordingly, I again only used bias and flat frame calibration in the workflow that produced the above images. Whilst the streaks are due to patterns in the noise being spread across the image due to errors in the application of dithering during tracking, it did indicate that the D7500 did have significant thermal pattern noise. I found this surprising because the noise in individual frames ( when looked at in isolation ) seems to be completely random. I thought that perhaps my memory had failed me and maybe the D5300 has the same level of pattern noise but my memory was being tricked. That is, all my recent images with the D5300 were taken at lowish air temperatures ( ~5 deg or so ) whereas the image above was captured on warm nights ( low 20s ) and so maybe the D5300 would be just as bad at higher temperatures. To test this I produced bias corrected master darks for both the D7500 and D5300 from images all taken at around 20 deg or just over. The images below have all been stretched using the same screenTransferFunction applied to the Pixinsight histogram tool. The results are striking ... D5300 master dark ( 47 subs, bias corrected ) - red channel: D7500 master dark ( 281 subs, bias corrected ) - red channel: D5300 master dark 100% centre crop - red channel: D7500 master dark 100% centre crop - red channel: And the histograms of the full size images ( red channels ) ... D5300 master dark ( red channel ) histogram: D7500 master dark ( red channel ) histogram: The Pixinsight statistics tool calculates the following: D5300: mean 2.3, standard deviation 9.3 D7500: mean 7.5, standard deviation 20.8 ------------- Analysis: The images and histograms clearly show that the D7500 has higher pattern noise than the D5300. In particular, from the histograms, 0.1% ( 6,286 ) of D5300 pixels are more than 44 ADU whereas, for the D7500 this figure is 27 times as great at 2.7% ( 141,305 pixels ). Furthermore, the master dark for the D5300 was only produced using 47 images -v- 281 for the D7500 so I would expect that this difference would be even higher with more D5300 frames. On the other hand, whilst not shown in the histograms above, my D5300 does have more 'very hot' pixels than the D7500 ( 579 pixels greater than 400 ADU -v- 10 pixels greater than 400 ADU ). However, these hot pixels are very easily removed via dithering during tracking and sigma clipping when integrating. The very large number of warm pixels however are very difficult to remove as dithering just places different warm pixels on top of each other. I went back and examined the 'random' noise seen in the individual D7500 dark frames ... and yes they do look random when seen individually, however, when flicking between a number of frames it is clear that the 'random' pattern is repeated in each frame! Conclusion: My D7500 has very significant thermal pattern noise, albeit randomly distributed in a fixed pattern. ............ Next steps (?) - I could use in dark subtraction during calibration to reduce the impact of pattern noise - however, as my camera is not cooled and the night's temperatures are constantly changing, any master dark will not closely align to the actual thermal pattern noise and as such dark subtraction may help but will not solve the problem - Using in-camera dark subtraction ( Nikon's long exposure noise reduction feature ) would almost completely remove the pattern noise from each frame. However, due to the extra random noise being introduced by subtracting another noisy dark frame from each light frame, as well as the reduction in total light frames by 2, the resultant images will suffer from higher levels of random noise. So whilst this would be an improvement with respect to the pattern noise, it is not a complete solution. - Third option, sell the D7500 and go back to using the D5300 ... -
Below is a comparison between single dark frames taken with the Nikon D7500 and D5300 with exposure durations varying from 1 sec to 240 sec ( my usual main light frame exposure ) all at ISO400. Firstly a graph of the standard deviation of the noise in the dark frames versus exposure time: The standard deviation of the noise is a fairly constant 2 ADU less for the D7500 compared to the D5300 ( pretty much the difference in the read noise between the two ) However, the difference is not just in absolute terms but also in the quality of the noise ... Below are the dark frames - ranging from 240 sec exposures at the top to 1 sec at the bottom: D7500 D5300 The D5300 dark frames clearly show the pattern in the read noise ( banding down the bottom ) and also have far more chrominance noise compared to the D7500. At 240 seconds ( the main exposure I have been using ) the difference is starkly different; the D7500 produces images with much lower noise that is significantly more even and random and hence more likely to be reduced during integration.
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The Nikon D5300 has a well-earned reputation as one of the lowest noise DSLR cameras used for Astrophotography. Now that I have a new Nikon D7500, I was keen to see how it compared to the D5300 in terms of the level of read noise and the extent to which that read noise is non-random ( and thus needs to be removed using a Master Bias frame to prevent it summing up during image integration). So here goes ... ......... A single bias frame Nikon D5300: ISO400, 1/4000th second: This may look pretty bad but really the extreme stretch is bringing out the very small variations across the frame: Standard Deviation: 3.53 ADU ( note: in this context, 3.53 ADU means 3.53 "units" on a real number scale ranging from 0 to 16,383 ( ie. a real conversion of a 14 bit digital scale )) The master bias frame looks like this: Nikon D5300: ISO400, 1000 x 1/4000th sec frames Standard deviation: 0.48 ADU The bands at the bottom are each 1 ADU brighter than the one above. Now for the D7500 ... A single bias frame from the Nikon D7500: ISO400, 1/4000th second: It is immediately clear that the single bias frame is cleaner. The statistics confirm this: Standard Deviation: 1.37 ADU And the master bias ... Nikon D7500: ISO400, 1000 x 1/4000th sec frame Standard deviation: 0.07 ADU The band at the bottom is 1 ADU brighter than the background. The improvement is very obvious Std. Deviation single bias frame: 1.37 versus 3.53 Std. Deviation master bias ( 1000 frames ): 0.07 versus 0.48 In graphical form ... Conclusion: The read noise in a single frame from the D7500 is around 40% of that in one from the D5300. This should give me greater flexibility to reduce exposure times and still ensure that the read noise is only an insignificant component of the overall noise. I will need to consider further the impact of the very low level of pattern noise in the Master Bias; it is so low that I will think about whether or not I still need to calibrate my lights with a Master Bias ( particularly for long exposures when the noise is dominated by light pollution and thermal noise ).
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d7500 My new love - the Nikon D7500
MikeODay posted a blog entry in Nikon D7500 DSLR for Astrophotography
It was love at first sight when I first laid eyes on the gorgeous noise curves of my dear Nikon D5300; young and beautiful with a great body and a large sensor, I was smitten. Now, well, what can I say... my roving eye has spied a new beauty; younger with heaps of energy that should go all night and , whilst I do prefer larger sensors, I can’t stop thinking about the noise curves hidden beneath that lovely new body... I struggled with my guilt for ages, I really did, but the time has come - I’m dumping the D5300 for the new love of my life; the Nikon D7500. -
Here my take on the Iris nebula earlier this summer. 4.5 hours of total integration time on a poorly collimated bresser 750s newt. Heavily cropped as the stars of this image set me on my first collimation journey. Hope you like it.
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Having upgraded from canon 1000D to Nikon D5300 how do users of the 5300 find it for Astro I will be using with APT , and how do you take flats as I can’t use Av mode as there is nothing in tools menu to choose no lens , do you use in manual mode and look at histogram ? .
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Hi guys After processing the Eastern & Wastern Veils separately a couple of months back, I've finally got round to doing the mosaic that was always the end goal (hence the framing of each panel). I'm not sure why I waited so long to do it, I think deep-down I was secretly dreading it really, as this is my first mosaic so I wasn't really sure how it would go. So this is just 2 panels, and each one has 5 hrs of Ha (15 x 1200s), with 3 hrs 20 mins of Oiii in one (10 x 1200s) and 3 hrs 40 mins of Oiii (11 x 1200s) in the other. So 17 hrs in total. APP was used for stacking, gradient reduction, and the mosaic creation. PS used for everything else. Ha assigned to Red, Oiii to Blue, and Green was synthesized from one of Carboni's actions. I've tried to push it as far as I dare to, did I over-do it do you think? I've resized it down to 66% to help hide some of the noise, and being a mosaic it's still plenty big. I might even end up bringing it down to 50%, we'll see. C&C welcome as always. I tend to finish my images very late at night, so I can sometimes fall into the trap of not seeing the image as clearly as I should! So feel free to be as harsh as you like ?
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The Great Barred Spiral Galaxy ( NGC 1365 ) in the Constellation Fornax ………………………. ( edit - star chart added ) The Great Barred Spiral Galaxy ( NGC 1365 ) - Chart ( please click/tap on image see larger and sharper version ) A full size ( 6200 x 4407px ) image can be downloaded from here. ………………………. Details: Below the equator, not seen from much of the Northern hemisphere, NGC 1365 passes very nearly directly overhead an observer situated near Cape Town, as Sir John Herschel was in November of 1837 when he discovered this “remarkable nebula” that is numbered 2552 in his book of observations from the Cape. Not called a “nebula” now, of course, this striking object is one of the nearest and most studied examples of a barred spiral ( SB ) galaxy that also has an active galactic nuclei resulting in its designation as a Seyfert galaxy. At around 60 M light years from Earth, NGC 1365 is still seen to occupy a relatively large area ( 12 by 6 arc minutes ) due to its great size; at some 200,000 light years or so across, NGC 1365 is nearly twice as wide as the Milky Way and considerably wider than both the Sculptor and Andromeda galaxies. This High Dynamic Range ( HDR ) image is built up from multiple exposures ranging from 4 to 240 seconds with the aim of capturing the faint detail in the spiral arms of the galaxy whilst also retaining colour in the brightest star ( the orange-red 7th magnitude giant, HD 22425 ). Also, scattered throughout the image, and somewhat more difficult to see, are numerous and far more distant galaxies. ................. Identification: The Great Barred Spiral Galaxy New General Catalogue - NGC 1365 General Catalogue - GC 731 John Herschel ( Cape of Good Hope ) # 2552 - Nov 28, 29 1837 Principal Galaxy Catlogue - PCG 13179 ESO 358-17 IRAS 03317-3618 RA (2000.0) 3h 33m 37.2 s DEC (2000.0) -36 deg 8' 36.5" 10th magnitude Seyfert-type galaxy in the Fornaux cluster of galaxies 200 Kly diameter 60 Mly distance .................. Capture Details: Telescope: Orion Optics CT12 Newtonian ( mirror 300mm, fl 1200mm, f4 ). Corrector: ASA 2" Coma Corrector Quattro 1.175x. Effective Focal Length / Aperture : 1375mm f4.7 Mount: Skywatcher EQ8 Guiding: TSOAG9 Off-Axis-Guider, Starlight Xpress Lodestar X2, PHD2 Camera: Nikon D5300 (unmodified) (sensor 23.5 x 15.6mm, 6016x4016 3.9um pixels) Location: Blue Mountains, Australia Moderate light pollution ( pale green zone on darksitefinder.com map ) Capture ( 3, 7 & 8 Dec 2018 ) 7 sets of sub-images with exposure duration for each set doubling ( 4s to 240s ) all at unity gain ( ISO 250). 140 x 240s + 10 each @ 4s to 120s total around 9.7 hrs Processing ( Pixinsight ) Calibration: master bias, master flat , master dark Integration in 7 sets HDR combination Links: 500px.com/MikeODay photo.net/photos/MikeODay <a href="http://www.flickr.com/photos/mike-oday">www.flickr.com/photos/mike-oday</a> Image Plate Solution =================================== Resolution ........ 0.586 arcsec/px ( full size image ) Rotation .......... -0.003 deg ( North is up ) Field of view ..... 58' 37" x 38' 55" Image center ...... RA: 03 33 36 Dec: -36 08 27 ===================================
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Went out on Sunday night to try and get some OIII for the Veil Nebula Bi-Colour Mosaic I’m currently working on. It ended up being a largely frustrating night though as I was fighting a big, bright full moon (in hindsight not the smartest decision I’ve ever made in fairness, lol). Factor in just enough intermittent clouds to exacerbate the issue even more, and when it finally set behind the neighbour’s house at 03:30am I was feeling pretty glum and was about to pack up for the night when I suddenly thought, what the heck, let’s try for a quick capture of 21P! As it was fairly low to the East, I had to disconnect all the cables and carry the whole rig to the other side of the house and re-do Polar Alignment, PHD calibration and focus. I did think about not guiding, as I knew the exposures were going to be short, but it just feels wrong not to guide these days so I decided to do it anyway just for peace of mind if nothing else. So I started capturing around 04:15ish and as astro-dark was due to finish shortly after 5am I decided to just do 40 subs of 90s each using the IDAS-D1 filter (we have streetlights nearby). Went in to grab a quick 60 mins of shuteye, except I overslept and didn’t wake until 06:30, so was then in a mad rush to pack up and get ready for work! Which meant I forgot to get Flats, but thankfully I was able to re-use the master Flat from my M13 image from a few months back and it seemed to work just fine ? Processing this one was interesting to say the least. This is my first comet, so I had to do some research beforehand. These days I always do my stacking in APP, but I had to go old-school and use DSS for this one due it’s special Comet-only stacking mode. So I did 2 stacks, a regular Median one just for the stars, and a 2nd Kappa-Sigma one aligned on the Comet (and using the same reference frame as the Median stack). Some subs were badly affected by intermittent clouds, so I could only stack 33 out of the 40 subs (and tbh 33 was really pushing it, quality-wise). I processed each one separately in PS and then layered in just the comet on top using the ‘Screen’ blending mode. I actually wasn’t aware there was red nebulosity in the background until I started stretching, and it certainly would have been easier to process had it not been there, lol. As expected, I have had to use quite a bit of NR compared to my normal amount, due to the pitiful amount of exposure to work with. Hopefully it doesn’t look too bad but let me know if you think it needs more or less of anything in particular. Of course, there’s only so far you can ever go with just 49 mins of data at hand. As the capture was done in such a rush, I didn’t bother worrying about the framing. I just input the co-ordinates into SGP and let it centre on the object for me. But having now worked out where in the sky this is, and looking at the FoV, I can see that had I rotated the camera 90 degrees then the Cone Nebula would have been in the frame. I actually haven’t imaged the Cone before, so I think this winter I will make a point of imaging it in it’s own right, and then I can re-use it to make a much more interesting version of this image with a much better background. Fun times! C&C welcome as always. And thanks for looking! ? Edit: Decided to make a few changes, so here's v2:
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The Cat's Paw Nebula ( NGC 6334 ) in Scorpius updated ( slight tweak to colour balance, a little brighter and tad more contrast ) ( please click / tap on image to see larger and sharper - a full size image can be seen here ) ...... original: ( please click / tap on image to see larger and sharper - a full size image can be seen here ) ……………………... Also known as the Bear Claw Nebula, NGC 6334 is an emission nebula near the scorpion's tail in the Scorpius constellation. Image details: Image centre ...... RA: 17 20 08.185 Dec: -35 52 30.91 Field of view ..... 57' 37.8" x 38' 51.8" Rotation .......... 0.00 deg ( North is up ) Resolution ........ 0.586 arcsec/px Telescope: Orion Optics CT12 Newtonian ( mirror 300mm, fl 1200mm, f4 ). Corrector: ASA 2" Coma Corrector Quattro 1.175x. Effective Focal Length / Aperture : 1470mm f4.7 Mount: Skywatcher EQ8 Guiding: TSOAG9 Off-Axis-Guider, Starlight Xpress Lodestar X2, PHD2 Camera: Nikon D5300 (unmodified) (sensor 23.5 x 15.6mm, 6016x4016 3.9um pixels) Location: Blue Mountains, Australia Moderate light pollution ( pale green zone on darksitefinder.com map ) Capture ( July 2018 ) 6 sets of sub-images with exposure duration for each set doubling ( 4s to 240s ) all at ISO 250. 168 x 4 min frames plus ~10 frames each for the shorter exposures Processing: Calibration: bias, dark and flat Integration in 8 sets HDR combination Pixinsight July 2018
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Hi guys So we had a completely clear night last Thursday and, as luck would have it, i was actually off work all week, so i was able to take full advantage. Well, mostly, as you'll soon find out. As it turned out this was a night that almost went completely awry. The first thing that i messed up was i forgot the external battery that keeps the D5300 powered all night. I only noticed this after driving the 45 min trip back to the family home where i do my imaging. Doh! Luckily though, i dipped into my big bag of astro stuff and found the 2 old camera batteries and charger that i used to use. By my reckoning it was last December when i last used them, so i was amazed to find they still had quite a bit of charge in them! So i was able to charge one while i used the other. Unfortunately though it meant i had to keep going out to the scope every 2-3 hrs to change battery, but tbh i was just relieved that i didn't have to drive home and lose another 90 mins of dark sky time. The next thing to grumble was the guider. For some bizarre reason, i could not see Polaris in the Fov in Sharpcap. I could barely see anything at all tbh so even though Sharpcap told me it was able to platesolve i was very dubious. And then when i came to do the Sharpcap PA routine, the adjustments were jumping around all over the place. It took me about 25 mins to PA instead of the usual 5, and i really thought the guiding was going to be a nightmare, but what do you know, it turned out to be actually really good. It even dipped below 0.5" at times. Go figure! Due to the floodlights of the sports facility (which is rather conveniently only about 100 yards away from the house) i was forced to start with Ha subs, then once they were turned off at 10pm, i switched to Oiii, as i knew the moon was coming up around 00:30 so i needed to take advantage of the darkest part of the night. I figured i'd go for about 3 hrs of Oiii, knowing that with the final filter change back to Ha again, i should end up with about 4-5 hrs of Ha in total. Well, after doing the last filter change and going back in to grab a nap for a couple of hrs, when i woke up and checked Team Viewer i noticed that the sequence had unexpectedly ended. Went out and saw that the 7 Ahr LifePo4 battery i use for the mount had died. I also noticed that the lens of the Finder-Guider had completely dewed up. As it turned out, the dew strip for it had failed so i've had to order a new one. I've also ordered a PSU to power the HEQ5-Pro from the mains, so fingers crossed i shouldn't have to worry about mount power over the winter now. All in all this was a bit of a pain of a night, as i normally only shoot 1 filter per night. Sometimes in the longer winter nights i might do 2, but i've never done 3 before. It's a real hassle too, as i need to shoot flats, change filter, re-frame and re-focus. All of which can take upwards of 30 mins. Hmmphh. So long story short i didn't end up with as much Ha as i wanted for this, which has meant it's been trickier to process than i would have liked. I should probably have just waited and done another night of Ha, but with all the hassle i have to go through to get any imaging done these days (drive, setup, tear down and pack away, drive home, sleep deprivation) i will always just try and use what i've got and move on to the next target. The Mean ADU level was quite low on this one, probably because the target is quite small and only occupies the centre of the frame. I've probably been lucky up to now, by mostly shooting larger targets, so i was disappointed with the low ADU levels, which are scraping the bottom of the barrel for me in terms of getting away from the noise floor. So i upped my exposures a bit, pushing as high as 25 mins, which is the nighest i've ever gone with the HEQ5-Pro. It seemed to still handle it quite well, although it didn't improve the Mean ADU level anywhere near enough. Full capture details: 3 x 1200s, 2 x 1380s, and 4 x 1500s of Ha 9 x 1200s of Oiii. 11 x 480s of RGB (with an IDAS-D1). Used for the stars and sky background only. 7 Hrs 54 Mins in Total. All shot with a Nikon D5300, SW 80ED, and an HEQ5-Pro. The RGB data was shot over a year ago from inner city Belfast (Red Zone) while i was testing out the new Rowan belt mod. It was just a test shot to check the guiding, so the 8 min subs were far, far too long in reality, hence a lot of the medium and bright stars are clipped. But i have to say, the IDAS-D1 together with APP did a nice job of cleaning it right up and making it at least useable (well, by my standards at least!). So on to processing. I've been playing with this for several nights now, and i just can't look at it anymore! i think this is the best i can manage with the limited data i have. It's been enjoyable and yet frustrating at the same time, lol. As usual, this has been stacked in APP and processed in PS. I used the tone-mapping method of processing, and created a synthesised Sii from a 50/50 blend of the Ha and Oiii. I then combined them in the classic Hubble Palette SHO. Obviously, not having any real Sii means i can never get the full range of tonal variations throughout. I'm also not completely happy with the colours if i'm being honest (especially the blue). That was the part i struggled with the most on this one. I've also attached below a quick and dirty HaRGB version, which took me all of about 30 mins to process (in total contrast to the SHO version, which i won't say how long it took!). As always, constructive criticism welcomed with open arms! Ok time for me to stop rambling on now ? Edit - Forgot to say, I resized the sSHO version down to 75% of the original (it's not worthy of 100% viewing).
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I thought i'd revisit this one, as i was never truly sure abut the processing originally. So with this one, i sought to improve the stars (they're a big improvement) but also bring out more of the dark nebulosity. Did i go too far though?! Looking at it again today i think i may have. 🤔 Details: Ha: 7 x 480s, 6 x 1200, 13 x 1200 (a little over 7 Hrs) OIII: 9 x 1200s (3 Hrs) RGB (with IDAS-D1 filter): 20 x 60s The usual Flats & Bias, stacked in APP and processed in PS. Gear used: Nikon D5300 (modded); SW 80ED (522mm FL); HEQ5-Pro; SGPro and PHD2. The original version can be seen on the Astrobin link. C&C welcome and clear skies folks! ps - At the moment this is still at 100%, but i'll probably end up down-sampling it to about 50%. I don't think it can hold up to 100% tbh. Edit - Here's the new, now much more toned-down, version. It's a clear improvement, so i'll have to keep reminding myself not to try and go for big & bright, when subdued nearly always ends up looking better! Original, nasty over-bright version: https://astrob.in/346428/C/
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Back in early Feb I tried imaging Markarian's Chain, but after 2 subs I encountered guiding issues (a first for me) so had to give up. So just for kicks and giggles, I decided to process them! ? So this is 2 x 10mins. With the D5300, 80ED and HEQ5-Pro. 'Stacked' (if it's even right to use that term!) in APP, and processed in PS. Then reduced to 75% for posting. Why oh why oh why..... I honestly don't even know myself ?
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Hi guys First things first, apologies for posting this one out of season. A combination of no astro dark, crappy weather, and being busy at work has meant that there's no imaging getting done at all these days. So, i've had to turn to old data to re-process, and this data set was an obvious candidate as i was never happy with how it came out originally. And looking back on it now with fresh eyes, boy did it need it! Nikon D5300, SW 80ED, HEQ5-Pro. 3 x 1200s, 2 x 1380s, and 4 x 1500s of Ha 9 x 1200s of Oiii. 11 x 480s with an IDAS-D1, for RGB stars only 7 Hrs 54 Mins in Total. Stacked in APP and processed in PS. Combined as SHO (using a 70/30 blend of Ha/Oiii for the Sii). The main differences this time were, using Starnet++ to create the starless versions, using more Ha in the synthesized Sii (70% instead of 50% last time), but mostly the improvement has come from toning down the stretch a lot (ok, a heck of a lot!) before making the colour map for the tone-mapping. From then on it was immediately apparent that i'd made a massive boo-boo first time round 🙈 I've included a 1080p rotated crop too, as i quite liked the framing. Feels like ages since i last did any NB imaging. I almost forgot how much i enjoy it! 🙂 And rather embarrassingly, here's the original. Try not to laugh too hard! 😂 😂 😂
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