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Everything posted by timwetherell
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In Search of the Southerly Messiers
timwetherell replied to DavidR100's topic in Observing - Deep Sky
Yes, i think you're right. But i'll definitely give it another bash next year -
In Search of the Southerly Messiers
timwetherell replied to DavidR100's topic in Observing - Deep Sky
Great report! You've inspired me to persist in my quest for M69 and 70! The biggest obstacle this year has been cloud. In the South west we've only had about two clear nights since June and even then there's been a layer of permacloud along the souther horizon! -
Which aperture is best?
timwetherell replied to Subdeo's topic in Discussions - Scopes / Whole setups
Ain't that the truth! -
Which aperture is best?
timwetherell replied to Subdeo's topic in Discussions - Scopes / Whole setups
If you're primarily interested in the moon planets and double stars then aperture is less of an issue than it would be on deep sky targets. Although increased aperture does lead to higher theoretical resolution the atmosphere will be the limiting factor with anything above about 8" especially in the UK. Ease of set up is another major factor. the bigger it is, the harder it will be to set up, the longer it will take to cool down and unless you're very dedicated, the less you may feel inclined to use it. I've tended to observe with scopes in the 4 to 8" range, though I've used scopes up to 30"! My experience has been that you need to double the aperture to make an "oh wow" difference - and that can get very expensive very quickly! I was looking at Jupiter once from a great site overseas with a variety of scopes. The best view was through a 7" astrophysics refractor - an 18" newtonian net to it was good too but there was no more to see than in the 7" and the contrast was ever so slightly less. However the ring nebula through the 18 was very much better than in the 7 -
I'm looking at getting a 4" portable refractor myself soon and to me a shorter focal ratio is important because I wan't the widest possible field of view. If I'm traveling to a super dark site, it will be to look at things like the North America Nebula and Andromeda galaxy which are very big indeed! A 4" f5.5 will give me 4.6° with a 31 Nagler vs 3.6° from an f7. So for me the Skywatcher Esprit 100 ED is looking like a good option, though it's not particularly cheap. I guess the fact that it would be faster if I did want to dabble with photography is an additional bonus. Though there'd definitely much more choice in the f7s
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Beautiful craftsmanship Andy!
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DIY folding Observing Chair w/ Plans!
timwetherell replied to Ad Astra's topic in Members Equipment Gallery
Thanks for posting this! I'm just about to begin building an observing chair myself and this has been really useful to me -
Show me your eyepiece/accessories case, please.
timwetherell replied to Leegsi's topic in DIY Astronomer
I've heard it suggested that in the modern age we should just own one eyepiece and change telescopes to achieve different magnifications! Ironically, it does make economic sense -
Mine three! will give it a go next time the clouds part
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Jupiter in a 7" refractor, just before dawn on the 4th of Jan
timwetherell posted a gallery image in Member's Album
From the album: Astro sketches
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And you'd also have to have an observatory built to accommodate such a beast, and some dark site land to put it on. Certainly well beyond my means, but it's nice to see such beautiful instruments being created and for those with deep pockets, enjoy!
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TEC now have a 10" Triplet Apo on offer! - It would be a fabulous instrument but at fifty grand a pop, I doubt there'll be 700+ made
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If they're held with a lock screw, perhaps sliding them right up the shaft when not in use to minimise the torque on the mount might be an easy and quick option? That's what I used to do with a 20kg counterweight on a very big "portable" mount I had once and it was fine. The main thing was to make sure that the weight and shaft were in the straight down position (as they would fall if you loosened all the clutches) so there's no strain on the worm gears etc.
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From the album: Astronomy inspired artworks
The Ariel Refractor, 12x16" oil on panel painting -
A few of my recent artworks with an astronomy theme. This is where I see my work heading in the coming years :)
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From the album: Astro sketches
Sketch of mars through my 7" refractor. Very low to the horizon so a fair bit of atmospheric dispersion and a lot of "shimmer" but the polar cap and some features were still visible even this far past opposition (November 29, 2016) -
Great images! You guys down under have the best of mars at the moment, It's barely crawling above the horizon here. I'm a big fan of sketching too! I think it really helps you to learn to "look" critically and discern detail that isn't always obvious at first glance. This was drawn last night through a 7" refractor. some atmospheric dispersion due to low elevation but most notably, mars looks upside down compared from what I'm used to from living in Australia. .
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Show me your eyepiece/accessories case, please.
timwetherell replied to Leegsi's topic in DIY Astronomer
Beautiful job!! -
I built this for my OTA. It clamps round the end and provides a solid handle for gripping it and because the handles are hollow, it doubles up as a zero power finder. There's probably commercial versions of the same thing available. Saves a lot of stress in mounting and unmounting
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Beautiful setup! That's the ideal mounting for a big refractor
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Fire and Theft: How can we avoid it and stay safe?
timwetherell replied to Sp@ce_d's topic in DIY Observatories
Personally I wonder if a dome "advertising" astronomy stuff may be less appealing to a thief than a shed "advertising" garden tools. I would imagine that it's far easier to sell a £200 petrol chainsaw that a weird lump of astro kit with half the bits missing. Astronomers tend to be a fairly tight knit community so whilst telescopes may be theoretically valuable I doubt they're easy to pass on and given that they're serial numbered, it's very high risk to steal and sell one - perhaps not that much of a concern to the druggie but to Honest Joe's ask no questions second hand goods emporium it might be? Secure it as best you can and remember bigger aperture is harder to steal, so the upgrade to a 24" can be justified on security grounds -
From the album: Astronomy inspired artworks
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From the album: Astronomy inspired artworks
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