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Filroden

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Filroden last won the day on January 24 2017

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About Filroden

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    Sub Dwarf

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    East Cleveland
  1. Filroden

    The "No EQ" DSO Challenge!

    The rear clearance looks worse than an SCT with image train for the evo mount. I think pushing the newt too far forward could cause issues in the wind.
  2. That’s a lovely pair (galaxies / scopes / cameras ... take your pick).
  3. My 1600 runs quite hot. Would that impact the brackets? They could raise camera temperature, or deform?
  4. Filroden

    The "No EQ" DSO Challenge!

    So the best way to reduce noise is...drum roll...more data. You only have 29 minutes of data using relatively short subs where read noise will have a greater impact. Although the nebula is bright and you have a lot of aperture, you will always have noise, even using the best stacking algorithms etc. Some post-processing noise reduction (using masks to apply the effects more strongly in the weaker signal areas) will help but the reduction is likely to be as noticeable as the noise.
  5. Filroden

    The "No EQ" DSO Challenge!

    I've never noticed any issues with my flats due to focus changes. On closer inspection, maybe the gradients are all pollution related rather than flats? It's just that each image appears to be vignetting. Here's a crop with the gradient removal and saturation boost. Pre-processed low res JPG isn't the best starting point but it should show you there is colour hidden in there.
  6. Filroden

    The "No EQ" DSO Challenge!

    I have to disagree. I took a closer look at your jpg of M33. After a quick background gradient removal to remove the worst of the vignetting/light pollution, I only needed to do two boosts to the saturation to see a pale yellow core and lovely blue arms. I think your problem is not the data but the calibration. I can't stress enough how important flats are to an image. I was terrified by them when I started. However, they are actually really simple to take and can be done the next day if you are careful. Here's what I do: - When I tear down the kit for the night I am careful to remove the scope/camera as a single unit (leaving it at its last focused position) and I take it all inside and leave it on the dining room table - The next morning I set up the tripod/mount again and put the scope/camera back on the mount carefully (so as not to disturb any dust) - I point the scope at any bright area of sky (cloudless or uniform cloud both work) - I fold about 4 pieces of white A4 paper of the end of the scope to reduce the sky brightness and act as a natural diffuser (white cotton also works but I like paper as I can fold it above and below the scope so it almost holds itself to the scope) - I then take flats, exposing them until they peak at about 50% of the histogram - typical exposures for me are about 0.1 seconds and I take 25 for each filter - Having captured the flats I bring it all back inside (you could do it outside but why be cold?) - I then take corresponding dark frames of the same exposure lengths as the flats (again, 25 flat-darks should be ok) [Note: for DSLRs you might skip darks and only use bias to subtract] The flats and flat-darks can then be added into your processing software of choice along with your darks and lights Voila. a much better starting point to begin processing.
  7. Filroden

    The "No EQ" DSO Challenge!

    That is a noticeable improvement in quality! The gradient is gone so the image colours look far more natural. You have some noise creeping in on the upper right of the image. Probably temperature/calibration related. I don't use GIMP but you might want to see if it has a despeckle function like Photoshop which helps remove single pixel noise like that. This hobby is all about finding those improvements. I never stop learning (and hopefully improving). Maybe not as fast as I would like but the weather prevents me from imaging
  8. Filroden

    The "No EQ" DSO Challenge!

    Nice to see some Southern objects on here! I'd be careful with darks on a DSRL unless it is cooled. You're more likely to add noise rather than remove it. I'm guessing from the target you're imaging from the heights of summer and probably somewhere relatively hot, even at night. DSLR's run quite hot without the addition of air temperature and unless you can exactly match temperatures of your darks to your lights you could make the image work. I'd recommend testing bias frames only. Flats will make a huge difference. You have quite a gradient though not quite centred (it seems to be centred in the SW quadrant). I notice the stars are elongated in that quandrant too. Do you have tilt in the system?
  9. Filroden

    HH 222

    Blimey. Getting 15 hours of clear skies in Grimsby must have taken almost as long as the bow wave to move into that position! I can't wrap my head around the scale of images like this. They just blow my mind. Thank you for sharing!
  10. Filroden

    NGC 1333 LRGB

    Second one for me. It ‘pops’ making the detail easier to see (on a bright screen).
  11. Filroden

    ZWO ASI 1600 MM washer/spacer

    Yes, and it’s fine. Here’s my normal set up. My OAG is on the diagonal but I have never noticed any impact on my images. Before you spend a lot of time trying to add spacers, take a few shots and check if it’s okay as it is.
  12. Filroden

    M81 and 82

    In PixInsight, once you've calibrated, cosmetically corrected (the process that would remove any hot or cold pixels not removed during dark calibration) and star aligned your images, your ImageIntergration process should look something like this: The rejection algorithm under Pixel Rejection (1) should be Linear Fit Clipping for larger stacks of images. When you mouse over the drop down a handy popup will appear and recommend the right algorithm for different size stacks. I find the default values in Pixel Rejection (2) to be fine. I amend the buffer size and stack size as I have a powerful PC with lots of RAM so I increase these to 65 and 10000 respectively, so more of the stacking is done in memory (at least it seems to work faster).
  13. Filroden

    NGC 1333 - high resolution New Year's delight

    Simply stunning! It’s got an amazing three dimensional feel. You can almost feel the turbulence in those clouds. Phenomenal processing.
  14. Filroden

    The "No EQ" DSO Challenge!

    I recommend mid altitudes (45-60) as alt-az mounts find it harder to track closer to the zenith, and the Evo mount doesn't have a generous clearance so you often can't even reach higher altitudes (or I couldn't with my refractor/camera).
  15. Filroden

    The "No EQ" DSO Challenge!

    I think it’s because NAN would be in the west and at a mid altitude. Almost the perfect location to avoid field rotation. The Evo mount can easily track up to 120 seconds at that focal length so just pick your targets to make best use you have a strong image though I think you still have a gradient. It looks brightest in the centre so my first thought was whether your flats were working but I think it’s probably just stubborn light pollution. I don’t know if there are any gradient removal tools in Gimp or Android PS, but it might help lift the Nebula.
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