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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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  1. Filroden

    M106 22 mins of Lum

    I agree with it but only to a point. Newer technology will (hopefully) continue to drive up QE and drive down noise, so you can reduce total integration time when comparing technologies from different generations. Are the newer CMOS sensors a new generation that have reduced the need? Probably not yet. And even if they did, there are always benefits to getting more data (though with diminishing returns). Your image does not surprise me. I think the 1600 produces an "adequate" image very quickly due to its low read noise but still needs a lot of data to make it "exceptional". I'll be really interested in seeing the effects of more data. Might be nice to stack a range of subs to see the benefits at, say 10 subs, 20, 40, 80, etc. It's also interesting to see you brightest star shows lensing effects. I have that same issue on my first gen 1600.
  2. Filroden

    The "No EQ" DSO Challenge!

    This is probably the wrong thread to discuss planetary/solar imaging as these are easily accomplished on alt/az mounts (probably even easier than EQ as setup is quicker). This thread is more about achieving longer exposure images, hence the suggestion of tools such as Deep Sky Stacker (alignment and stacking) and StarTools (processing). Registax is a very good piece of software for aligning, stacking and processing planetary images. Nonetheless, I'm glad you shared the image. It's beautiful :)
  3. Well done. Those are amazing images.
  4. Filroden

    The "No EQ" DSO Challenge!

    I forgot to say. As your image seems to have no dust bunnies you could probably still take the flats now and they might last you over a few sessions.
  5. Filroden

    The "No EQ" DSO Challenge!

    As someone has already suggested, taking flats would probably offer the single biggest improvement to the image. You have some significant vignetting in the image which flats will deal with. I used to stress about taking flats but found they were very easy on a sunny day. Just aim your camera/lens at a part of the sky away from the sun and put 3 or 4 sheets of plain white paper over the lens. Find an exposure that generates a histogram that peaks about 50%. You may need more or less paper to control this. Once you've flattened the images (which can be done in DSS and other stacking software) the light pollution will show a more even gradient (more linear rather than circular) and will be easier to remove. That said, given how much vignetting and light pollution you're fighting, I'm even more impressed with your result
  6. Filroden

    The "No EQ" DSO Challenge!

    I’m not sure how real the colours are but each of your stars showed very subtle differences in their RGB values but they need to be stretched to extremes to show it. I have an action in Photoshop that increases star colour. I think it takes colour in the halo and maps it back into the white core. I also pushed vibrancy and saturation to make it easier to see. in reality, you’ll get a better result from the original image. I think the magnitude limit is a function of aperture and total integration time so to go deeper you need to stack many more subs.
  7. Filroden

    The "No EQ" DSO Challenge!

    What I love about this is that you've taken a really sharp widefield image with hand-held (albeit supported). There's even star colour data in the image though you really need to push the processing hard to bring it out. I hit it hard with the star colour hammer (hope you don't mind) to show it's in the image (blues have gone a little purple): With that nice field of view you might want to try some other areas and capture some clusters.
  8. Filroden

    The "No EQ" DSO Challenge!

    Isn't it great to be imaging again? Looks like you got focus and only a little trailing in the 66 subs you've stacked. I'd say your main issue with the image is, as you've suggested, its green colour. DSS is great for stacking but I would never recommend using it for processing an image. It's too blunt a stick. Even a free package like Gimp will offer far more control over your stretching (small, iterative applications of either levels or curves adjustments to minimise star bloat and protect the brightest areas from over-exposing) and also for colour balancing (again, curve adjustments but in the individual RGB channels). Give the processing another try. Use the autosave file from DSS with no processing, and try something like Gimp or a trial of StarTools, etc. You should find, with some careful stretching, that you can show good star colour across the image.
  9. I would get this until I put the camera on a dedicated USB3 port and dialled back the download setting in SGPro to 40. Had minimal effect on download speed but I now rarely see any errors. (1600mm)
  10. Filroden

    Horsehead nebula in Narrowband

    I have to agree with everyone about this image. It’s one of the most beautiful I’ve seen. You made the right decision to keep the green.
  11. Filroden

    M94-Please have a go

    I think you mean your background It really was good RGB. It didn’t need anything else. I find star colour can best be done in the stretch, not afterwards. I find the ArcsinhStretch with a value of 2 applied 4 or 5 times gets enough colour into the image and then complete the stretch with either a MaskedStretch or HistogramTransformation. ArcsinhStretch on its own bloats the stars too much if used on its own.
  12. Filroden

    M94-Please have a go

    Hi Rodd Late to the game as usual! As many have said already, you have good data here. I've tried to do as little as possible in processing as the data is so nice. I only used the RGB. My steps in PixInsight were: ChannelCombination DynamicCrop DynamicBackgroundExtraction PhotmetricColorCalibration A few small iterations of ArcsinhStretch with a MaskedStretch to finish CurvesTransformation on both saturation and RGB TGVDenoise A light SNCR in green HistogramTransformation to bring the background down to about 23/23/23 There are many more steps that could have been applied along the way, including extracting an L channel to apply deconvolution, and applying some noise reduction in the linear stage. Likewise, better processors than me could enhance the contrast much better. I applied a little sharpening (heavily masked to restrict it to the core) and noise reduction in Adobe Lightroom. Overall, I haven't brought out the halo as much as others but I like the colour balance.
  13. Filroden

    M 16 Ha

    Here's an example of the background stretched about as far as I can take it (the top 80% of the histogram was fixed and only the lower 20% was stretched). I can see almost concentric patterns in red, green and blue. I'm now wondering if it's my flats? Are you seeing anything similar? (BTW, this is an LRGB image)
  14. Filroden

    M 16 Ha

    When I say background and gradients I don't mean simple linear gradients across the image but quite complex gradients that still seem "regular" but polynomial in definition rather than linear. I always suspected it could be complex due to reflections, e.g. the fences around the garden reflect the street lights so you get second order gradients from multiple directions. I like your analogy of IFN that isn't really there. Or its just my processing or calibration! I still don't have OIII or SII filters but I cannot see why good narrowband filters at any frequency would not be similar to Ha. SII, being deep into red should be similar. OIII, where the worst of the light pollution peaks, could be more affected but nowhere near a much as RGB. Ha can be taken under moonlight, OIII not so much so I think the same might apply for bad light pollution.
  15. Filroden

    M 16 Ha

    That's a fine mono Ha result. Like you Rodd, I find the 1600 great in Ha. I use 4 min subs and cannot complain. The camera really is sensitive. I can do automatic focusing in Ha using 8 second subs (albeit using 2x binning) and most targets can be faintly seen in the stretched result! I'm also frustrated by RGB. The gradient in each channel seems to be very different and irregular. When combined it leaves behind a terrible background. I still need to really learn how to use background extraction.
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