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ollypenrice last won the day on May 11

ollypenrice had the most liked content!

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About ollypenrice

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    Imaging, Cycling, Thinking, Literature, French culture, Mountains...
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    South east France, Lat 44.19N.
  1. Aha, it's working now, Peter. Although we're talking tiny, the Ha found a nice little pair of propellor-like extensions just out of the inner core. Olly
  2. Doesn't strike me as gradient-afflicted. In fact that's a nice flat sky to my eye, though I might bring in the black point a tad in the interests of contrast. Nice natural image. Olly
  3. Some audacious reds and blues there but if you have the signal you can flaunt it! I like the lower right part of the image best, I think, the dust having really fine modeling and the darkest parts being entirely unclipped. That's signal for you... Olly
  4. Not sad at all! There are two simple processing mods which would greatly enhance it. The image is clearly black clipped, meaning the black point has been brought in too far and has nibbled into your precious data. The example I use on my courses is of this very target, the first image being black clipped: If you leave more space at the left hand edge of the histogram pedestal you'll get a much healthier result: The other thing is colour balance, which strikes me as being very colour-cold or blue. I would try to get the histograms of each channel aligned so that they are lined up at the top left of each peak. Great stars for unguided imaging. Well done. Olly
  5. I make it a rule not to put my bacon sandwiches on the corrector plates of catadioptrics while letting them cool down... lly
  6. One of my favourite galaxies and you have it tight focus with good guiding. It just needs more. Don't they all! Olly
  7. He did, but he also ended up buying a TEC140 instead for this focal length... (Slight difference in price, though!) Olly
  8. Best move, I think. Good luck. Olly
  9. I was thinking of an improved primary cell, a stiffer and lighter tube, maybe an improved secondary holder and better focuser. People do get the standard ones into good shape but given the number of people marketing improved GSO RCs I'm surprised that the 190 hasn't had the same attention. Olly
  10. It's on here somewhere but I can't find it! It's also on Astrobin: https://www.astrobin.com/full/365412/0/?real=&mod= I'd like to get the outer parts a bit brighter with more data. It has a murky look about it! I've tried to upload the Ha core but it won't let me for some reason. Olly
  11. Do you need to trade off sharpness for noise at all in this image? I can't see why you should have to do so. I don't see any galactic details that really beg for sharpening and the noise is, as ever, confined to the fainter signal which can be isolated via masking for NR. If you want to tighten up the stars I'd do that by isolating them first. I don't use PI for this stage of processing but the principle of isolating the different parts of the image for either sharpening or NR is the same whichever graphics program you choose. In Photoshop it would be child's play to put one of your versions over the other and then select and erase those parts of upper one which you dislike. Olly
  12. Is this powered hub just a generic one? Personally I avoid hubs like the plague and put up with a lot of USB cables. Olly
  13. It's already F5 and has a front lens. Would it like to be pushed much faster even if you found a reducer? Not sure. This scope seems to have gone quiet of late but I always thought it a very interesting one with huge potential. They do need to be very well set up but I remember Steve Loughran getting great results with his a good few years ago. I remain surprised that nobody, so far as I know, has made a more mechanically up-market version using the stock optics. F5's good. Fast but not silly-fussy on depth of field for focus. Olly
  14. It won't be as effective as you hope, I'm afraid. As Gina said, the luminance channel will not be parfocal with itself across the spectrum it covers so stars, in particular, will be bloated and soft. Also, your thinking would probably be sound so far as red and green are concerned but blue would almost certainly be a disaster. The short wavelengths of the blue end of the spectrum are the hardest for the opticians to control, the more so as they head towards violet. The bandpass of a blue filter is wide enough to pass a range of wavelengths coming to very significantly different focal points so the blue channel would be soft and bloated, probably with large blue halos. Again, as Gina said, you might find that your theory would work for narrowband imaging because the NB filters are more nearly monochromatic and so effectively exclude all but parfocal rays. In theory, at least, you might also need to use a program which not only aligned your three channels but which resized two of them to match a third because a major refocus might have a perceptible effect on image scale. Whether it would be significant or not I don't know. I began imaging with a very early TV Genesis corrected for visual use in the pre-CCD era. It gave predictably bloated blue and L stars but was excellent in NB where it was as tight as the Tak FSQ which replaced it. Also Ha/OIII/SII imaging keeps well away from the problem blue end of the spectrum. Olly
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