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rubecula

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  • Content Count

    221
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About rubecula

  • Rank
    Star Forming

Profile Information

  • Gender
    Male
  • Interests
    Astronomy, Lepidoptera
  • Location
    North Hampshire, UK
  1. rubecula

    Another filter issue?

    Wow, what a difference Gradient Exterminator makes when you use it properly Thanks Dave
  2. rubecula

    Another filter issue?

    Adam, yes the image was fully calibrated with flats, bias and darks and the image I put up had not been edited with Gradient Exterminator. I'll try isolating the nebula and run exterminator on the rest of the image. Mmmm don't use PixInsight...........more expense? Thanks
  3. rubecula

    Another filter issue?

    Yes, I have 24 flats for for this filter.
  4. The image below is a couple of hours worth of stacked Ha frames of the Medusa Nebula that I was hoping to combine with OIII and SII. I hope you can see in the attached jpg that there's a sort of wide pale halo around the nebula. When I put this into the green channel it is much more noticable. I wasn't a particularly cold night and I did have the dew heaters running. The following night I used the same filter on the Whirlpool nebula and there's no sign of the halo. Any idea of the cause or how I could get rid of it? I tried a couple of runs of Gradient Exterminator and that removed the darker arear in the corners but left that darker area around the nebula. Thanks
  5. Thanks guys, the use of groups plus setting a reference frame has worked a treat
  6. The filters I have are 36mm unmounted so its difficult to be absolutely sure which is which by just looking at them. As it happened my guess based on the above images was right and the last lot of images were as expected
  7. When composing an image with mutiple channels (LRGB or Ha OIII SII) I've read that in DSS you should register the images so that the stars all line up when you use a function such as Merge Channels in Photoshop. So when registering images does that mean ALL the images i.e. 3/4 sets of lights plus darks, flats and bias or just the lights?? Thanks
  8. rubecula

    Too much red stretching?

    Thanks all, I'll have another go at this based on your suggestions. David, I did severely cut back the green as with that filter (only) there was a very strong glow on the left hand edge and that was the only way I could see to get rid of it. I thought it might have come from Alnitak but it didn't effect the other filters. Perhaps there is another way of removing it with another layer without altering the colour balance of the whole image. I tried HaOIIISII last night but if the weather stays fine I'll be doing LRGB tonight and it will be interesting to see if I get the same green glow. Thanks again
  9. rubecula

    Too much red stretching?

    Thanks Tim, I see what you mean, I'll have another go at it
  10. rubecula

    Guiding help

    Presumably your mount is polar aligned? When you framed the target did you make the last adjustments in the North and East directions (this reduces backlash)? Did you adopt the Guiding Assistant recomendations?
  11. rubecula

    Guiding help

    Run the guiding assistant from the Tools menu, Then accept its recommendations and try re-calibrating.
  12. I finally got my first image with the Atik 383L+ and first using filters. Its 6 x 600 sec in each of L, R, G and B stacked in DSS and processed in Photoshop. I've had several attempts at processing it being guided by tutorials here in the lounge and a couple by Sara Wager. Thanks to those who go to the trouble of creating them. One big issue was a strong glow on the left hand edge that only occured with the green filter. Anyway, the question: The image looks OK-ish to me but the histogram, particularly the red looks a bit chaotic. Is this what you would expect in a processed image? Any suggestions for improvement gratefully received. Thanks
  13. Thanks Mike, Carole and Chris. I'll re-assign the filter locations in SGP and see how I go. And Carole, thanks for letting me know I'm not the only one .
  14. I bought a used filter wheel on-line and it came with the filters in place. I asked the seller which slots the various filters were in. I took some images and the LRGB ones looked OK but Ha looked wrong. I took the wheel apart and inspected the filters. Two of them seemed wrong so I left them in the same positions but changed the filter set up in SGP to match what I thought was correct. I've just taken some images this evening and think I may have it wrong still. The images below are single 600 sec subs that have all had the same single curves stretch in Photoshop and then saved as jpgs. I think, from the top that they are Ha, OIII and SII. Do you agree? Thanks
  15. rubecula

    NB imaging Question

    Great question ( I was about to ask it myself). Thanks for the answer, just what I wanted to know.
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