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Everything posted by Lee_P

  1. Ooh interesting, I didn't know there was a D3. Thanks for letting me know. I'll give it a go and will report back -- might be a while though, given all the cloud that's forecast! p.s. my P stands for "Pullen"
  2. Ah, I calibrated them with Flats and Darks, but not Dark Flats. Something else to read up about!
  3. Having consistency in brightness was a good shout, it does make it easier to see the differences. I've tried to do the same with the original Iris Nebula data. Any thoughts on why the noise tests a few posts above show no real improvements after four hours? That's got me scratching my head.
  4. I went down the eyedropper route. In for a penny, in for a pound! Whaddya make of that?
  5. Yep, they were dithered. I'll have a crack at making the galaxies the same brightness.
  6. I think you're right actually. I'm confused, surely it should get smoother with more data? Even the pattern of noise looks the same. Have I messed something up in pre-processing? I'd be happy to do this, but you'll have to give me some tips on how! In the way I've been doing basic edits on these tests, the galaxy naturally gets brighter.
  7. As CloudMagnet suggested, I've repeated the experiment with an extreme crop of M81. Looks like the same result to me: the first 10 hours are the most valuable. Data after that are still useful, but the impact certainly isn't as dramatic. I'll repeat with L-eXtreme data on a nebula once galaxy season has passed!
  8. I think you're right, and it's funny you should say that because I've been editing the IKO Iris Nebula data trying to do exactly that
  9. Absolutely! That would make side-by-side comparisons rather difficult though. Not impossible I suppose, but too tricky for me FYI this is the final edited photo with all the data.
  10. Super, well feel free to suggest what you'd like to see on a website dedicated to OSC from a city, Knowing that the effort will be useful to at least one person might motivate me to do it!
  11. Thanks! The new-generation CMOS OSC cameras are very good. And work well with filters like the L-eXtreme. I'm increasingly coming to think that conventional wisdom like "don't use OSC from a city" and "you need a LPS filter" is outdated. To answer your question, for each image in this experiment I followed the same few steps in PixInsight. They were mostly to get a set of images that could be displayed side-by-side for fair comparison. * Crop * ColorCalibration * AutomaticBackgroundExtraction * EZ SoftStretch * SCNR (remove green) * Slight CurvesTransformation
  12. Great! I'm tempted to make a website dedicated to OSC imaging from city skies. We're a particular niche. Could be a project for the Summer...
  13. Thanks, I'm glad you found it interesting. No light pollution filter used. I haven't found them to be effective from my location. I posted another experiment, on this topic, here:
  14. Wow, I've never worked with such good data! I decided to focus in on the central nebula and try to bring out its details. PixInsight: * LRGB combine * DBE * ColorCalibration * EZ SoftStretch * Create a mask, apply LocalHistogramEqualization to add contrast to the central nebula * Starnet++ to create starless version and starless mask * Save starless version as a TIF and export to Lightroom... Lightroom: * Topaz DeNoise AI * Boost Clarity * Boost Saturation and Vibrance * Save as TIF and export to PixInsight... PixInsight * PixelMath to
  15. Good shout, I'll download that and will have a play. Might make me a bit depressed about the quality of my data though
  16. I'd be interested to see a similar experiment to mine, using your 30 hours!
  17. Well, I do happen to have 24 hours of data for M81 / M82, so perhaps I'll repeat the experiment for those! Once some nebulae are up in the sky again, I'd like to try using my L-eXtreme filter.
  18. I thought it would be interesting to see the difference increasing integration times makes using my kit and sky conditions. So, I took 20 hours of data I'd collected on the Iris Nebula and produced images of different total integration times. Then I cropped in very close, and performed some simple edits in PixInsight, just to allow for comparisons. I thought I'd post the results here in case anyone could find them interesting or of use The earliest hours make the biggest difference, perhaps unsurprisingly! I'd say that the nebula's structure is th
  19. **Reduced to £80, including recorded delivery to a UK address. Offers considered. Payment via bank transfer or PayPal, buyer to pay fees** For sale is my IDAS LPS-D1 48mm (2") light pollution filter. Full text on the filter reads: IDAS LPS-D1 48mm MBT & IGAD JAPAN. The filter is in excellent condition, and comes with its original case. Good under moderate levels of light pollution. (Not recommended if you've got lots of LED streetlights nearby). https://www.rothervalleyoptics.co.uk/idas-d1-light-pollution-suppression-filters.html http://icas.to/space/optical-filter/LPS-d1-e.ht
  20. I think we're in the same boat. Maybe there's a filter out there that would help us with broadband targets, but for now I'm happy to just brute-force it with long integration times. I took the 20 hours of data from my tests, added in another four for good luck, and produced this image. It's not great, and a 400mm focal length scope isn't ideal for these targets, but at least we can get something even with our skies.
  21. My tests seem to support this. I am assuming that it's LED lights swamping my skies though -- I don't know for sure that they're widely used in Bristol, but I wouldn't be surprised.
  22. I recently saw FLO were selling a new light pollution filter: IDAS LPS-P3. I shoot OSC from Bortle 8, and figured this might help for broadband targets! (I use an L-eXtreme for narrowband, which works brilliantly). I already own an older-style IDAS D1, but don't routinely use it as I'm not sure of its effectiveness. Well, with these two filters in my possession, why not have a shootout and see the results? For this test I used an Askar FRA400 f/5.6 72mm Quintuplet APO Astrograph and ZWO ASI 2600MC-PRO USB 3.0 Cooled Colour Camera. All shots were from Bristol (UK) city centre. 120-second e
  23. Star trails around the North Celestial Pole. Taken from Bristol city centre, with no light pollution filter. The brightest line is Polaris -- close to the North Celestial Pole, but as this telescope view shows, not directly over it. * 21 April 2021 * Bristol, UK (Bortle 8 ) * Telescope: Askar FRA400 f/5.6 Quintuplet APO Astrograph * Camera: ZWO ASI 2600MC-PRO * Mount: Orion Sirius EQ-G (turned off after initial slewing) * Software: PixInsight, Photoshop, Lightroom * ASIAIR PRO * 180 x 120 seconds ------------------------------------------------------------ Total integrat
  24. Thanks, I guess the FRA400's larger aperture helps.
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