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ollypenrice last won the day on June 7

ollypenrice had the most liked content!

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About ollypenrice

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    Neutron Star

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    Imaging, Cycling, Thinking, Literature, French culture, Mountains...
  • Location
    South east France, Lat 44.19N.
  1. I was initially alarmed by 'Boob of the day' as an imaging challenge on SGL but, like the others, I rather like this is well. Olly
  2. I keep the stacks. The individual subs would take too much space. (Stacking old and new stacks is not optimal but still works very well indeed.) Olly
  3. I'll never be able to download those files with the current internet situation here but the initial image seemed oversharpened, to my eye, and I was instantly suspicious of deconvolution. Shock horror but I don't use it at all. I think Ciaran has nailed it, with a result that looks fluffy and yet has all the detail crystal clear. Olly
  4. Good stuff. I think the nebulosity is a great success. The stars, though, as is often the case with SCT deep sky images, are pretty large. Of late I've been seeing what happens when I use Starnet++ to de-star an image and then paste the original linear data on top of that in Photoshop's blend mode lighten before stretching that top layer till the stars begin to appear but in smaller size. It's quite simple and might work well with this data. Olly
  5. Post deleted. I hadn't seen the second page! Nice result. Olly
  6. So would I. I dare say the CMOS niggles (internal reflections, microlensing artifacts, funny OSC stellar colours, stellar haloes) will be sorted out in time but the demise of CCD is rather worrying. Olly
  7. You can't focus on galaxies and nebulae because they are fuzzy, you must focus on stars. You may need to find a bright star to find focus first. Zoom in to pixel scale and focus to get the star as small as possible. Also, just as you hit focus, you'll probably find that lots of tiny stars suddenly appear. That's the spot! You might also try Googling Bahtinov Mask - a much-loved aid to finding focus. Olly
  8. That's a truly cracking rendition. The contrast between acute sharpness in the gas/dust structures and smoothness in the background brings the structures forward and makes them look three dimensional. It also draws the eye towards the features of interest. And all of this is achieved without the image looking processed at all. (The holy grail of processing.) I reckon you've extracted all that your data had to give and stopped a gnat's crotchet short of exaggeration. Spot on. Olly
  9. As everyone will tell you, and with good reason, you first need the best possible mount. If the mount won't track the sky with the necessary precision it doesn't matter what scope or camera you have, your pictures will be blurred. So it's mount first. Now, what is 'the necessary precision?' This depends on the resolution at which you're going to be imaging. The proper units of resolution are arcseconds per pixel (how many arcseconds of sky land on one pixel). The more sky per pixel, the lower the resolution. For a given camera the resolution is controlled only by the focal length since the pixel size is now fixed. You can image at short focal length with only a modest tracking accuracy. As your focal length increases so does your need for accuracy. Not all that far along the path from low to high resolution you need a good mount and and autoguider for it. So the message is clear: on a budget keep to a short focal length, perhaps with a prime lens like a Samyang 85 or 130. (The 130 has a devout following and its own thread on here.) If you stick with lens imaging you might be happy with a Skywatcher Star Adventurer. Personally I would make the HEQ5 the next step up. I can't see the point in an intermediate step which would soon leave you frustrated. I would also make this my first purchase: https://www.firstlightoptics.com/books/making-every-photon-count-steve-richards.html (When I started, Steve hadn't written it. It would have saved me a lot of money had it been available...) Olly
  10. Ah, that makes sense. I thought it was a bit small for a garage unless you drive a Messershmidt Cabin Scooter!! Olly
  11. Thanks, but I meant the building in the background! Now you say you're below road level I can guess that it might be a garage or road-level storage unit? I was just curious about it's elevated position. Olly
  12. I have to ask: what's the elevated timber structure standing on rows of brick? lly
  13. Sorry, I thought you were using a 130 Newt. My mistake. It's unfortunate that the term 'aperture' is used in normal photography as it is because F ratio and aperture are not the same thing. In the case of a camera lens with a given focal the shorthand use of the term does no harm but it's the source of endless confusion in telescopic imaging. Olly
  14. No, it's important to use terms properly in AP or you'll confuse yourself. Your aperture was the aperture of your telescope, so 130mm. Don't become fixated on F ratio. Once you change a scope's focal length with Barlow or reducer you'll find that the term F ratio does you more harm than good. Olly
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