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JamesC

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About JamesC

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    Star Forming

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    Exeter
  1. Don't overtighten your boots. It cuts the circulation. Same if you really pack them with thick socks - it can be counterproductive.
  2. I'm not sure it is necessary to get anything. With a solid tube you shouldn't be getting dew on the primary while you are outside observing. Once you bring the scope back inside the mirror will be cold and you may well get moisture condensing on the mirror then. Once the mirror has warmed up a bit the water will evaporate. The primary mirror is the part of your scope with the highest thermal mass so it is last to cool down when you take it outside and also last to warm up when you bring it back in. Can you not just leave the scope tilted over so there is no dust settling on the mirror? Alternatively you could just open the small hole on the lid and leave the focusser open too. That is probably enough.
  3. My experience with a 114mm starblast was that a dewshield was not necessary. It will probably help improve contrast by keeping stray light out the tube though. By contrast, I found a dew shield was necessary with a 12" dob. I think the difference is that the secondary on the starblast was largely covered by the bit that holds the mirror so it never presented much area to the night sky. On the 12" the secondary was large, presented a large area to the night sky and cooled quickly. Without a dew shield the mirror would mist up after a couple of hours. I have often wondered if gluing a think layer of cork on the back of the secondary of the 12" would have stopped it cooling so fast and so prevented dewing. On the other hand, would it have kept it too hot and caused tube currents? Also what would you do if you ever wanted to recoat the mirror? I was never brave enough to try.
  4. I love the simple elegance of the Newtonian design, but I have to concede that refractors have their appeal. Aside from the issues normally covered, I think it is the low maintenance and durability of refractors that makes them so desirable. With Newtonians: - The mirrors will eventually need re-coating. - You may want to clean the mirrors every few years (contentious). - You have to collimate regularly (not a big issue with practise). - There is always the risk of disaster, i.e. dropping something down the tube. I think these factors prevent Newtonians becoming objects of desire, instead they are supremely practical work horses. I don't have a lot of experience with refractors, but things I don't like about them (apart from the cost per unit aperture) are: - They are surprisingly heavy which limits their portability and also requires a serious mount. - The eyepiece location is inconvenient. - I don't like left/right inversion (I prefer fully inverted). To me the best refractors are binoculars - the main problem with those being hand shake!
  5. Interesting. My 300p flextube had a similar thing. I've now sold it on and I guess I did knock off a bit when deciding the price because of the flaw. The scratch/flaw/crack/whatever-it-was never got any worse despite plenty use over 3 years in varying conditions. When I removed the mirror to clean it, I felt a lot better because it's such a big hunk of glass the scratch/cut looked minor. I checked the figure of the mirror with a Ronchi eyepiece and it seemed very good to me. When I got the scope, I wondered about making a fuss and sending it back, but decided I couldn't be fagged! I find it really interesting that mine wasn't the only example. I have no idea how these features come about.
  6. Just tested with the binoculars on tripod with objective poking through cardboard and a bit of white paper behind. Surprisingly effective and vastly better than the glasses. I could see the little grouping of 3 spots near 1486 and the 1490 and 1492 groupings (Sunspots). I'm going to have to go eclipse chasing now, so my investment in glasses isn't wasted
  7. Wow! That was cool. Just cut a hole in some cardboard, stuck one of the binocular objectives through and was projecting on a piece of paper. Reckon I could see sunspot 1486. While I was watching a jet plane went across the solar disk leaving a contrail behind!! Only problem with the set up is I can't hold the binoculars steady. Thinking about taking a tripod now.
  8. Thank you. Glad to see you moderators are on the ball. The glasses have that warning on them, but it doesn't hurt to repeat that kind of thing. Perhaps projection is the way ahead. I think I might do that David.
  9. I just got some eclipse shades. I'm going to be away from home for the Venus transit and fancied something I might see a small black dot with in the unlikely event of it being clear. I thought about binoculars and solar film, but decided against it. Just wondering - can you see anything else with these things? Just been looking at the Sun and it looks like a featureless orange disk no spots or anything as far as I can see.
  10. I'm not even an imager, but I've seen on other threads that you can have a scope too well balanced. Apparently you are best to have it slightly biased one way or the other so the drive is always working in the same direction. If the motor flips from pushing on the gears to slowly giving ground to gravity you can get a bit of wobble. Alternatively sell the EQ6 and get a Dob!
  11. Sounds like you are along the right lines. There are plenty of miradores where you can park up and take a view. I liked one near the cable car station. It is an amazing location to do astronomy from because it feels like you are in a crater on an alien planet or something. Thinking back on it I don't know why I didn't try the parking for the cable car station, perhaps there was a reason or perhaps I was just shy. Anyhow if you've got a car you're sorted. Annoyingly there is a bit of noticeable light pollution, but it's still an excellent location. I hope you are taking some binoculars or something with you. I did see binoculars on sale there but they were all the ruby red 'night vision' coating type - i.e. rubbish. You would be better buying something you would like for the long term and taking it hand luggage. I crazily took my Starblast on an EQ1 mount!! I still can't quite believe I did that. These days I would probably take something like a Sumerian Optics scope or a small APO on a camera mount. Mind you the Starblast is darn good value for money. Tenerife is really beautiful - I'm sure you'll love it. Hope you get a spot of walking in. Actually just driving around is amazing. I remember watching sunrise from a viewpoint on the TF-24 after a night's observing. The road along the ridge on the eastern part of the island is some piece of engineering. This is a link to a thread I wrote 3 years ago! http://stargazerslounge.com/observing-reports/83179-my-visit-tenerife.html
  12. While I'm thinking about it, you might start to be disturbed by coma in 2" eyepieces. Add a coma corrector and a 2" OIII filter to the wish list!
  13. Generally agree with the above. You need at least 3 eyepieces: one wide angle - maybe around 6mm exit pupil or whatever you think you can realistically handle; one for DSOs - I think the calls for 13mm are about right; and one for planetary - personally I would go for about 300x (which many people think is too much). For the wide angle, I would consider the Meade 5000 28mm SWA which is still a reasonable price here. Actually I might even be tempted by the 34mm, even although the exit pupil would be too large - just to get the additional field of view (the 31mm T5 would solve that problem, but it's a jumbo eyepiece). For the DSOs I'd either go for Meade 5000 14mm UWA, which I know is pretty good, or else take a punt on the Explore Scientific 14mm 82 degree eyepiece, which I've never seen. There is a school of thought that you may as well go straight for the expensive eyepieces and then you don't need to think about upgrading, but personally I think I would be happy with the above. If that was still too pricey, at f4.8, I think I'd go for generic 52 degree plossls. Planetary is tricky. I might go for a 5mm Nagler, even although the eye relief is tight (the 6mm Delos is probably a much more comfortable eyepiece). There is no budgeting on wide angle planetary eyepieces. Of course you could build an equatorial platform and then use an orthoscopic!
  14. Don't recommend trying to correct the scope. You soon get used to navigating with the inverted view. I thoroughly recommend the right-angle erect image finderscopes. Much more comfortable on the neck than those straight through ones and easier to orientate yourself. Makes it easier to translate from binoculars to finder scope too. Actually I often found it easier to see things in the finderscope than the binoculars because it doesn't suffer from hand-shake. Red dot finders are also useful but if you're just getting one I'd go for the finderscope. You will need to make a dew shield. I also kept the eyepiece cap on when I wasn't using it to stop the finderscope eyepiece from dewing up.
  15. Yeah, until the bin man comes around and decides to do you a favour...
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