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Petergoodhew

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Posts posted by Petergoodhew

  1. 3 minutes ago, alan potts said:

    That's another beautiful image there from the Spanish side of you scopes, must find some new words, but another I don't believe I have seen before, maybe worth a try with my M/N 190-mm one day.

    Alan

    Thanks Alan. I do tend to go for the more obscure targets! This one isn't that common in part because it's fairly low on the horizon at 12 degrees declination. Even in southern Spain it was only just peeping over the observatory walls.

    Peter

    • Like 1
  2. NGC 7479 (also known as Caldwell 44) is a barred spiral galaxy about 105 million light-years away in the constellation Pegasus.

    This is a total of 21 hours of integration.

    Captured on my dual rig in Spain.
    Scopes: APM TMB LZOS 152
    Cameras: QSI6120wsg8
    Mount: 10Micron GM2000 HPS

    NGC7479.jpg

    • Like 11
  3. 23 hours ago, alan potts said:

    A really wonderful capture, 57 hours hells bells, that dedication for you, 3 hours for me is just about enough then I get fed of seeing the same thing on screen. I don't think I have seen this before and you can see where the name comes from.

    Alan

    Thanks Alan. It’s rarely imaged because the core is very small and very bright. I’ve searched extensively online and haven’t found any images of these outer halos.

    Peter

  4. Before starting an imaging run I now do some test images with different filters, exposures, and binning to see which combinations work best. When I examined the OIII 1800s bin 2x2 test image I was surprised to see an asymmetric outer shell with intricate structures, and so factored this into my image capture plan.  This is the result. There is also a very faint diffuse OIII shell that is even further out from the core.
    I found processing this to be a real challenge, with 7 filters, and exposures varying from 30 sec bin 1x1 to 1800s bin 2x2. Integrating images with such extreme dynamic range was also a challenge. I was concerned by some lighter parts of the sky background, but after checking with other images available online it became clear that this was integrated flux nebula.

    This is a total of 57 hours of integration.

    Captured on my dual rig in Spain.
    Scopes: APM TMB LZOS 152
    Cameras: QSI6120wsg8
    Mount: 10Micron GM2000 HPS

    NGC7009.jpg

    • Like 18
  5. That's got to be the best 7331+quintet I've ever come across Olly.  It's worth foregoing the IFN for this!

    Interesting how things aren't what they seem.  I had always assumed the quintet were all together. You got some really good colours too - the three hours per channel were well worth it. 

    Smashing job. Bravo.

    • Thanks 1
  6. 4 minutes ago, Craney said:

    Fantastic image.  Well done.

    This is a faint, faint target.....  A case of pointing and hoping for me.     I tried for 3 hours and got a 'possible'  blur.   I shall be inspired by this.

     

    It's tricky. The bubble is only visible in narrowband - more so in OIII than Ha.  I did 30-minute subs binned 3x3 to extract as much signal as I could.  Clear dark skies help a lot too!

    • Like 1
  7. 3 minutes ago, steppenwolf said:

    Very nice indeed, Peter, this one is already on my 'hit list' if we ever get another clear night or rather nights!! This is a lovely rendition.

    What filters did you use for this image?

    Thanks Steve. I've been wanting to have a go at this one for a long time. The filters were all Astrodons. Ha was 5nm, OIII was 3 nm.

  8. A planetary nebula in the constellation of Cygnus - close to the Crescent Nebula.
    Only relatively recently discovered (2007) because of its extreme faintness hidden in bright hydrogen clouds.
    Also known as PN G75.5+1.7

    43 hours total integration, captured from Extramadura, Spain.

    Scopes: APM TMB 152 F8 LZOS

    Mount: 10Micron GM2000 HPS

    Cameras: QSI 6120wsg8

    APM TMB 152 F8 LZOS, 10 Micron GM2000HPS, QSI6120ws8

    Soap.jpg

    • Like 26
  9. 5 hours ago, carastro said:

    Interesting.  I imaged this target not so long ago, but the Soap Bubble is not in the FOV, so was thinking to add an extra panel, but does the soap bubble show up in broadband or narrowband as my original image in in narrowband?

    Carole

    Carole, I find it's much, much more faint in broadband than narrowband.

    • Like 1
  10. On 19/07/2019 at 23:23, Datalord said:

    This is so interesting. I'm currently processing NGC6888 and have a thread on the selection on subs here: 

    I came to the exact opposite conclusion. Difference is that I don't have the final image to show for... yet. 🙂

    And btw, fantastic image. Well done!

    I don't this there's a right or wrong to this.  I've some images where selected the best subs made no difference at all - and others where it does. I think it will be down to the data. If there's very little difference between the quality of the subs, and especially if the target is faint, adding more will of course improve signal strength and thus help with deconvolution. However if a few subs are of exceptional quality, only using them could turn out to be the best strategy.

  11. On 18/07/2019 at 15:50, alan4908 said:

    That is a very impressive Bubble Peter.  Excellent stars and good detail.

    One thought....on the Ha 30min subs used for the detail you mentioned above that you decided to use the best 15 out of 128. I was curious to know if you'd tried using an alternative approach: use a much higher percentage of subs,  which would give you a slightly less detailed result but much improved signal to noise ratio.  This would enable you to apply a much stronger deconvolution which would assist in recovering the lost detail. 

    Alan

    Hi Alan, yes I've experiemented with different selections of subs.  The sugnal is very strong in these and so signal to noise isn't a problem. 15 subs represents 7 1/2 hours of data. Here I was able to do 200 iterations of deconvolution. I find that larger numbers of subs does reduce the clarity, and so settled on 15.
    Peter

  12. A rarely-imaged extremely faint planetary nebula in the constellation of Serpens Cauda.
    It's also known as RCW 181 and PN G038.7+01.9.

    Captured on my dual rig in Spain.

    RGB 20x600 each

    Lum 22x600

    Ha 21x1800 bin 2x2

    YM16 finalise.jpg

    • Like 13
  13. 7 hours ago, Brian Maurer said:

    Wow, you got so much detail.

    Thanks Brian - the secret is lots of data, and then using just the best for pulling out the detail. Here I had 128 30-minute Ha subs but used only 15 for the fine detail. Deconvolution, high-pass filtering, and Annie's Actions helped too.

  14. A more conventional target for a change - and one of my favourites. This time revisited with more data.

    82.5 hours total integration HaOIIILRGB
     

    Image captured on my dual rig at EyE, Extramadura, Spain

    APM TMB 152 F8 LZOS, 10 Micron GM2000HPS, QSI6120ws8

     

     

    NGC7635 PG.jpg

    • Like 28
  15. A very faint planetary nebula in the constellation of Virgo. It is at declination -20 and thus very low, even in Spain, just hugging my visible horizon. It is only 800 light years away with a span of 1.5 light years. The central star is estimated to have a temperature of over 73,00K compared with our sun at 6,000K.

    29 hours 10 mins total integration (19x1800s OIII bin 3x3, 16x1800s Ha bin 3x3, 52x600s Luminance bin 1x1, 12x300s Red bin 1x1, 12x300s Green bin 1x1, 12 x300s Blue bin 1x1)
     
    Image captured on my dual rig at EyE, Extramadura, Spain

    APM TMB 152 F8 LZOS, 10 Micron GM2000HPS, QSI6120ws8

    Abell36v3.jpg

    • Like 9
  16. 1 hour ago, ollypenrice said:

    You're going great guns on these rarer planetaries, Peter, and this is another winner. Just to be awkward I'd like the red stars from the first one and the other stars from the second! 

    Great result, love it. And yes, stars and background sky are the hardest things to get right in any image. (This is why I love my 'inefficient and outmoded' Atik 11000. Those big pixels just seem to do it all for you!)

    Olly

    Thanks Olly - let me see what I can do for you!

    Abell61 V3.jpg

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