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riklaunim

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  1. If you stretch a lot / stack a lot without a good dark frame it can show up. I have a different camera with IMX 432 and its amp glow is like this just shifted more to the bottom part
  2. Images were made with an Omegon veTEC 432 M camera (IMX 439, 9um pixels), Bresser 200/800 f/4 Newtonian, and Explore Scientific Coma Corrector. Around 20 x 120s frames were stacked for each image. Flat/dark, Graxpert to limit gradients aside from some weird reflection-like ones... Theory and details on https://rkblog.dev/posts/astronomy/m27-nebula-in-various-bands/ CLS-HSI (LRGB type image): H-alpha/IR/CLS: IR on green will show stars hidden by dust or emission from the nebula (check how some stars are brighter here than above): H-alpha / Neutral oxygen 630nm / [He II] 587nm: Some nebulae can realistically use [O I] and [He II] emission lines for imaging although they won't be as bright as the more popular ones and require custom filters. The infrared wider band can be handy more often to go through the dust in a wider range of nebulae. Channel shots: Astronomik CLS-CCD: Baader [O III] standard filter: Baader H-alpha standard filter: Optolong [S II]: Astronomik ProPlanet 807 - infrared, skipping all major emission lines as well as going through dust more easily: [He II] custom filter with halo from either light pollution or the filter itself (same wavelengths as sodium lamps): [O I] neutral oxygen 630nm: Astrodon UVenus: Old SCT C11 images: [O I]: [He II]:
  3. Bresser 200/800, Explore Scientific coma corrector, Omegon camera, Baader Neodymium 2" filter, around 100 x 60s frames. Focus is almost there and some reflections sadly went in as well even after some gradient removal (Graxpert): I do have street lights from bottom left/right angles (and some bandpass filters don't have such issues) so I'm guessing it's hitting the inner OTA wall and reflecting to some extent. And before M33 was in the field of view I did shoot M15, which looks way better (although at the 60s the core was already a bit overexposed):
  4. My f/19 DK14 got upgraded by my friend (who made the scope in the first place) to have a much better primary mirror holder and now it seems to hold the mirror properly, no weird ghost edge on the Moon and so on... although still now sure if it's that sharp (and I still have to move secondary bit closer to have enough backfocus for ADC and filter wheel)... QHY174MM, Orange IR-longpass: And as the seeing looked really good, a bit of over-scale with 2x Barlow on top of it: And few Moon shots:
  5. Depending how fast the temperature is rising/falling C14 may not be able to follow it - thus never reaching ambient and always having air current/boundary layer around the primary mirror. With all SCTs I had, and especially C14 I used an active fan to push air through the whole OTA so when I started using it it was forced at ambient - but if the temperature change was to steep then around 40-60 minutes and it would start to drag again. As for collimation you can start with looking visually to see if the error is large or what's the thermal state of the telescope.
  6. Self-made is likely not an option Not that skilled nor a 3D printer.
  7. Depends how long wavelength you want. 1100-1600 nm is often done from standard ground observatories.
  8. Silicon sensors stop responding to wavelengths longer than 1100nm. This isn't that much of infrared (more like "200% red"). Some time ago Sony did release a different sensor that operates above 1000nm but the price is similar to a small house. Also on longer wavelengths light can go through dust more easily, which is visible even with standard sensors (Ha filters vs PP742):
  9. Anyone here used Alpy 600 or something similar? I'm looking into slit based spectroscopes and I don't see much options (sanely priced). I used Star Analyser before and now I want something with a slit to target nebulae but also planets, like specific features in Jupiter atmosphere or like sodium emission around Io and so on (and comets if they show up).
  10. Nice, good to see more effort into this... although they did get beaten out of the market I guess to make it a constant meaningful revenue. Now to do some pull requests, maybe sort cameras list ASCOM vs rest of the world etc
  11. RedCat 51, Omegon veTEC 432 M (9um pixel, 1600x1100), Svbony UHC, 180s exposures (around 30 frames for Pleiades and around 60 on the horse).
  12. Can't say about visual but for imaging it's just 6". Depends what quality you are expecting. Good resolution starts around 8" and then going up. For imaging it's all about aperture.
  13. That's why I posted the raw stack Nicely done.
  14. Did a simple "experiment" of collecting 1700 frames at 30 sec over few nights for M5 (RedCat 51, ASI178MM, UHC filter) to see how much background I can get out of it and what's the noise will be like. Sadly not that much magic detail there, but at least it does look nice FITS file: https://www.dropbox.com/s/9fzjw8ewo3n1m76/base.fit.zip?dl=0 bin2: bin1: link
  15. Actual webcams no as they don't support longer exposures nor good image quality. There are some cheap entry level dedicated cameras like some QHY/ZWO/Svbony models and that's better used with a lens or very short focal length APO refractor. 8" Newtonian will give a very small field of view (only DSLR for that) plus small pixels of such cams don't help either (quite quickly you will run into guiding problems for 8" telescope - requiring guide setup and way more precise mount setup assuming it can track well). Even if you are getting a DSLR - try imaging with like a 100 mm lens first (all attached to the EQ mount, no telescope) - that's way less sensitive to tracking errors.
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