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wingeing Pom

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Everything posted by wingeing Pom

  1. Mizar & Alcor

    100 subs was massive overkill, your images should be effectively noise-free with anything over 50 subs. I had one imaging "expert" berating me for not knowing anything about signal to noise ratio as I didn't take into account the gain in signal to noise with exposure time. Problem with signal to noise increase with exposure time is that the increase is not all that big, and also it flattens off rather quickly especially if your skies are not too good. So in my location the exposure time signal to noise ratio increase flattens off in about 5-minutes meaning that I am getting no (further) S/N ratio increase in the 20-minute exposures I need to take to get faint stuff and the only way I can get the noise down in galaxy or faint nebula images is to take LOTS of subs. The reason why I have often said you need at least 8-hours of good data to get a first class image is that if you take a typical sub length as 10-minutes and then have 50 of them, you're talking just over 8-hours. It only took me about 10 years to work this stuff out Greg P.S. Oh - and by the way - all your 50 subs have to be GOOD. You have to go through every sub and check they are o.k. as I now from experience you can actually see the degradation in the stacked image with just ONE bad sub in 100. P.P.S. And that is also the reason why I run multiple imagers in parallel - I increase the number of subs in a given time by the number of imagers. P.P.P.S. Dithering is essential. So is good image calibration with good flats and bias frames.
  2. Mizar & Alcor

    Mizar & Alcor in Ursa Major taken with the Sky90 array. Greg
  3. Mizar & Alcor

    That's just a case of getting the signal to noise ratio up in the first place which means LOTS of subs. When I first started imaging with the original Hyperstar I used to aim for 100 subs (although they were only 1-minute long). I used to get glassy clear completely noiseless images but they didn't go very deep. So it's a trade off. For things like star piccies you don't need a long exposure time - for things like galaxies and nebulae you do - this is one reason I prefer star piccies Greg
  4. Pelican

    Playing about on Photoshop 2020 I put together everything I had on the Pelican nebula and then also added DSS data from the same region. Everything stitched together using REGISTAR. Greg
  5. Barnard's "E"

    I combined all my Sky90 data of this object together with the DSS data from the same region. Barnard's "E" is a dark nebula lying close to the star Tarazed. How many stars do you think are in this image?? Registar says there are 165,000 Greg
  6. Barnard's "E"

    And here's a Noel Carboni process of JUST the Sky90 data. Greg
  7. New machine

    Just curves plus Noel's "Enhance DSOs and reduce stars" Greg
  8. New machine

    Managed to get Photoshop and all the associated bits onto a more up to date machine (HP Z600 workstation) as my main computer is slowly losing the plot. Did a test process on some Taurus molecular cloud data - 42 x 20-minute subs. Greg
  9. New machine

    This is a single frame with the Sky90 array.
  10. The Great Conjunction of the Century

    Great work!!!!!!!!!!!!!! A super record to have. Greg
  11. Planetary Debacles

    Yep - I thought a monitor had suddenly died - it was actually the VGA splitter cable that fed the monitor, the monitor was fine. I now have a spare monitor on the way - and to top it all off - I didn't actually need the splitter cable. Think senility is setting in. Greg
  12. The positive feedback is way worse than that. The more forests that are cleared the greater the CO2 and the global warming. This then leads to all the bushfires you have seen and the forest fires seen in America and Russia which further reduces the trees and further increases the CO2. We are on an exponential rise to extinction and Gaia is fighting back in the only way she knows. She's probably done this a few times before as well, so she knows what she's doing
  13. SW Black Diamond 120mmx1000mm Refractor

    Before putting Trius M26C OSC CCDs on the back of the Canon 200mm prime lenses, I tried the lens out (for astrophotography) with a Canon 5D MkII DSLR. The results were absolutely superb, and as the 5D MkII is now an "old" model you can pick them up cheap. Greg
  14. NGC7331 massive crop

    I took 14 x 10-minute subs of the NGC7331/Stephan's Quintet region with the Sky90 array. This is a massive crop of the region. Greg
  15. NGC7331 massive crop

    The above data combined with some very old original Hyperstar data - came out well Greg
  16. Pleiades ultradeep - with colour

    There is a loss of colour in my ultradeep Pleaides image (the one with several 1-hour long subs) due to color bleaching from effective over exposure. So I mixed the ultradeep image with an intermediate exposure image (that had better colour) to get the result below. Greg
  17. A little conjunction action.

    Excellent!!!!!!!!!!!!!!!! Greg
  18. Ruchbah region

    Just starting to get bloody cold here Greg
  19. Ruchbah region

    Got out for my first imaging session of the season last night (16/09/2020) and fired up the MiniWASP array to test out the Sky90s and the Canon 200mm lenses. Decided on the Ruchbah region as it was well placed, and here is a 5 x 10-minute test shot using the 200mm lens. Out again tonight imaging the Schedar/Gamma Cass region again using the 200mm lenses but this time using 15-minute subs.
  20. Pelican

    Blimey - film!!!!!!!!!!!!!!!!! You really are an expert!!!!!!!!!!!!!!!!!!!!!!! Greg
  21. Pelican

    After a long battle I managed to get all 3 Sky90s up and running and grabbed this one last night with 12 x 10-minute subs. Greg
  22. Got today's EPOD

    M31 with the tips missing. https://epod.usra.edu/ Greg P.S. If you look at EPOD on the wrong day (i.e. not today the 24th) then you will see a different image. Here it is from now on https://epod.usra.edu/blog/2020/09/epod-20th-the-splendid-andromeda-spiral-galaxy.html
  23. Deeper Gamma Cass

    I combined the recent Gamma Cass data from the 200mm lenses with some earlier deeper data and got this result. A lot more of the Ghost Nebula is visible in this one. Greg
  24. Pelican

    That's interesting - Michael Sidonio (another Aussie) used to be pissed off with all the North America nebula pics from the Poms as he said he couldn't image it. But then again I don't know where in Oz he imaged. Greg
  25. From Gamma Cass to Schedar

    Last night's effort with the 200mm lenses and Trius M26C OSC CCDs, 20 x 15-minute subs. Greg