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Everything posted by Shibby

  1. I can't say I share your opinion on the Pacman, but yours is definitely one of the best images I have seen of it! I like the composition, with the "centipede" as the subject. How many nights does it take you to gather 30 hours??
  2. It's actually better to let it dry as slowly as possible to achieve maximum strength. In fact, leaving standing water on top of it is the best way to get the strongest cure. Of course, for our purposes, that's probably not necessary.
  3. It really should be red - the Hα wavelength is bang in the middle of the red part of the spectrum. It's weird that the light passing through looks magenta; I'll have to try that! It shouldn't look magenta unless some violet is leaking through, but that's at the opposite end of the spectrum. Normally, with a modified DSLR or CCD the blues are overpowered by the strong Hα reds. That's why I think there are some really nice, colourful images like this one from unmodified DSLRs.
  4. Ah yea, you're quite right actually; forget that! Scaled down 50%, a target with this would look the same as an f/6 with the same aperture, right? The FOV would be reduced, though.
  5. Essentially, you're looking to improve your resolution. As you correctly identified in your original post, what's important is arcseconds / pixel. That's determined by pixel size, focal length and the seeing conditions. Aperture can also limit your resolution - for example, the ED80 has a max resolution of ~1.43 arcseconds. The long focal length of the F12 Mak you mention gives a resolution of 0.56"/pixel with your camera. I don't know where you're based, but that's a higher resolution than the average seeing conditions in the UK, so is not useful. Also, F/12 is very "slow", meaning you'll need very long exposures for DSOs like nebulae. A 150mm F/5 Newtonian would be a good upgrade, giving you both faster optics and also 1.35"/pixel instead of your current 1.94.
  6. I immediately thought of the habitable exoplanets catalog when I started reading this thread. I think this is one example where the illustration can tell you a lot about the planet at a glance, which is fine so long as you understand that there's a huge amount of guesswork going on. The good thing about the Oumuamua illustration is the clear text "Artist's Concept" in the corner. All artist's impressions should have this text baked into the image, but sadly that's quite rare so the images often get syndicated without the message. So long as the message is clear, I don't object to pretty concept images being used; it's completely understandable that a news publisher wants to draw readers in. I know that doesn't really answer your questions; I don't know how information is passed to artists or how accuracy is ensured, but I do think it's important that known information is conveyed first and foremost.
  7. What a superb image in every way. Love it.
  8. Yeah that should be fine - mine is similar and runs lovely.
  9. Looks fantastic Rob. Nicely processed with lots of detail on show. My monitor isn't big enough really, we're all gonna have to get 4K screens now!
  10. Also: price. Originally, my finderguider + webcam setup was far cheaper than OAG + decent guide camera. (The webcam was unlikely to be sensitive enough for an OAG setup). With my current OAG + optics, I don't have the back-focus
  11. Another thing to try is picking a different reference frame - a good scoring one near the middle of your dataset.
  12. It's highly likely I'm missing / misunderstanding something here, but can't you rotate the scope in its rings to achieve your vertical balance, before moving on to the horizontal balance?
  13. Try wrapping an elastic band around the outside of the filter. This has solved similar issues for me a number of times!
  14. Is that right? I've always found that longer guide exposures give me a slightly calmer trace; because of that dreaded seeing being more "averaged out". I still haven't figured out the ideal interval, though. I find myself frequently changing it throughout a session. Probably to no real effect! As for guiding with the 840mm guide scope, it's certainly possible but you will find fewer stars - and therefore fewer bright stars - in your narrow FOV. If that's an issue on a certain target, you can tweak the pointing of your guidescope relative to the imaging scope if you have to, but don't go silly far away or you'll end up with field rotation on longer exposures.
  15. So, the latest plan is to replace my filter-wheel and its integrated OAG with a separate OAG + FW, allowing me to mount the prism further forward in the train. One bonus is that I can upgrade to 7 filter positions. My guess would be I'll need a low profile OAG, such as this on FLO, which I believe has a profile of 13mm. Thing is, I still can't be sure that focus of both cameras would be reached. Does anyone else have an OAG setup with their MN190?
  16. I've been looking at doing something similar and decided it'd probably be a good idea to heat the enclosure to prevent dew forming on the window and causing false readings.
  17. Obviously not one for the purists, but I think it's a good idea as an alternative to video astronomy; should be simpler for anyone to setup and use. Good for kids - my little niece was actually quite upset when the views of the Pleiades through the telescope weren't as good as the preview on Stellarium! Thankfully, the moon was a winner.
  18. As has been said, there is no telescope that's perfect for both imaging and visual. But the best all-rounder is a Newtonian reflector. I would recommend the Skywatcher 150-PDS, which performs well visually for DSOs and is suitable for DSO astrophotography if you add the coma corrector. A setup I used for several years.
  19. Looks like, here in the UK, we had ~1400 hours of sunshine, which I believe equates to around 32% of daylight hours. Far less than Spain, but still feels like it should be lower than 32% based on the number of clear nights!
  20. Thankfully at F/8, it won't be too difficult to collimate. The E-ELT, however will be a right pain at F/0.93 !!
  21. I guess I can forgive that then! At least it's nice and dark when you do get some clear sky. 3.30 seems to be about my limit too, unless I have some very strong coffee brewing all night and no work the next day. Nice M33, by the way.
  22. Very nice project and I also like your website. Congrats on the observatory, I look forward to seeing the rest of your build log.
  23. Stunning image - great work. I've either never seen this, or just not seen it anywhere near this well presented!
  24. Whether those graphs are showing pixels or arcsecs, I hate you both! Especially since you seem to have encountered some clear skies!
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