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boboco

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Everything posted by boboco

  1. Avoid the Hubble photos! In fact, unless your an imager, avoid any photos as they will always be "better" than the thing your seeing with your own eyes, especially once your past the top 10 "wows"; once you have the right level of expectation you will appreciate what you are seeing more.
  2. Shock horror - the moon is shrinking!! But you do a long time to save up for the new scope... "100m shrinkage occurred within the last billion years" ;-)
  3. How accurate is this site? Its new to me...
  4. I just got a reply to my enquiry and I am beginning to think this is genuine... Anyway if anyone does actually see it I would like to know what you think. Response: "Thanks for your email. You are probably aware that the telescope is very large and very heavy. Being a female, 5 feet tall and seven stone wet through it probably weighs twice my weight plus and towers above me. I have been waiting for relatives and friends to come and help me move it so I can take some photographs but no luck so far. If I can get some help soon the pictures will be changed. I can take pictures of the top half of the telescope but not a full length one in the area where it is stored. It is a used item not an abused item. Lovingly cared for by one very careful owner. So please keep looking. Thank you. "
  5. Depends where I am observing, there are some places (Puttenham common car park south of Guildford) where I keep a very large metal torch (the 4 D cell Maglite) hanging from my belt "just in case". But despite that the most spooked I have ever felt was when a fox just sat and watched and watched and would not go away, quite nerving.
  6. Very sus, I just emailed the seller asking for a photo and more details (as its too good to be true and a shame to miss the chance *if* it is genuine).
  7. I think you also need to have the platform change angle (tilt) on the "horizontal" axis as it rotates about its "vertical" axis. Something like this http://www.equatorialplatforms.com/Alumplt_anim2_smallb.gif If you look at this site Equatorial Platforms: Compact Model in the second picture you can see that there are small curved edges to the base board which will tilt it as it rotates. They are also quite clear in this Equatorial Platforms: The Awesome Aluminum Platform . They probably are not especially difficult to make (okay impossible for me ;-) ) , but you would need to know exactly what the curve should be. Am very eager to hear if it works. Cheers, Karl.
  8. If I recall correctly that image is usually used in a err... slightly different "usually done in the night time" kind of activity.... ;-)
  9. Not sure about the degree of pollution but its possible to see the nebula with an 8" and good conditions. Quoted from here Cepheus - Notes by Tom Polakis 8" With low power, some fields of lumpy darkness are seen, a huge nebula! 10" Immediately S of Mu Cep is a 5' clump of crowded faint stars surrounded by dark neby and lanes, I1396 cluster is 60 stars typically 10m to 12m nicely defined across 1 deg, well centered is 6m star with two tight companions, field is crossed with thin, dark lanes for surrounding 3 deg, UHC view is less impressive, but brings out some patches, including 10'x3' <1/2 deg N of cluster center 13" Rich field and resolved stars in 11x80, 60 stars pretty well detached over 30' perfectly centered on 5m star with companion 10" p.a. 120 and 20" p.a. 330, companions are 9m, brightest neby is 1/2 deg NNW and is uniform 10'x5' tangent to ring around star, 40' NE is another haze 20' across, many other glows prominent over 2 deg field, slight enhancement with OIII or UHC, especially first patch
  10. As a "bouncer" (I started, got very disappointed and stopped for a long time then got back in) I think there is one other very important resource which is missing for the person contemplating starting.... That is a single resource there a large number of objects are shown at different apertures and under different conditions. You can find web sites that compare some - but you have to hunt. This will remove a lot of the initial disappointment that I encountered, and I am sure I was was not the only one, when I used my first scope - an etx-105. I had carefully selected the 3rd largest scope from the line (avoiding the 125 as I was told it was heavy for mount). While I knew it would not be hubble and was aware that it would not even live up to the photos on the box I was not prepared for the complete lack size and clarity and in many cases invisibility of the experience that greeted me. I would probably have made a better first choice (though I still have the etx-105, its great for its purpose) if I had the knowledge before making the putchase.
  11. and transporting a 14" solid tube is a major exercise vs a 10" (but worth it).
  12. I am not a physicist, but I wont let that stop me ;-) It seems to me that theoretical physics is getting way off track and is constantly inventing new, ever more bizarre, theories to explain away anomalies in the previous set of bizarre theories, and far from Elephants or Turtles its "made up concepts all the way down and well keep making them up because its more fun that doing real work". To take it back to something I do know (software architecture) when you have to fix bugs in previous bugs which were already fixes on earlier bugs then its time answer some fundamental questions about whether the basic architecture is correct.
  13. BBC is saying that there may be an aurora visible from the UK tonight & tomorrow night - but not sure how far south (fingers crossed for Surrey!).
  14. Pretty much ditto - both seem to be the best for me also - but I use a right-angled finder with an amici prism so that the image is correct.
  15. Regarding noise. This works on the LX90, so I assume its an autostar feature and will work on the ETX also - there is a "quiet" mode, which slows the skew speed and does make it MUCH quieter.
  16. I have done a little research, and out of season is clearly the best time from getting some darkness, but it also puts up some challenges. I had assumed that you can take a fast cat from Guernsey, but it seems thats only available from Jersey (50 mins). There are some smaller operators (and smaller slower boats), but there are further restrictions (25KG total luggage limit). There is an option to charter a very small boat, but to be honest I don't fancy that with the seas around there (both from the likelihood of my chundering and from the impact on any equipment). So will need to consider taking big bins (which is a disappointment). Or look at getting the scope freighted over (which is scary). Anyone know what the typical autumn / winter weather is like? Joselin, would it be correct to assume its similar to Guernsey? Anyway will keep digging. Cheers, Karl.
  17. Hi, I just got back from holiday and spent a day of it on Sark (but unfortunately not the night). While I was there I noticed that they are planning on becoming the first island to get Dark Sky status (similar to a Dark Park). So I wondered if anyone has spend the night there and has any comments on the quality of the sky? There are some serious issues with getting large equipment (14" dob) over there (ferry from Guernsey looks like best, but it will be a bumpy ride both on sea and land as there are no roads) but I may try it out later this year - oct or nov (am happy to coordinate with anyone else who is interested). Cheers, Karl.
  18. A Thing of Beauty indeed! Do you have the plans for this? While I am pretty hopeless with wood, I do have an uncle to teaches woodwork and a 10" f4.8 dob that's not being used much. f4.8 vs f4.5 - could I copy directly or would I need to vary the distance on the struts considerably? Cheers, Karl.
  19. Hi, I was not too sure where to put this, but its a visual representation of the gravity wells for the planets and a few satellites. Intention is to show the scale of effort required to escape gravity from each body. Its on a "science cartoon" site, but don't let that put you off ;-) http://xkcd.com/681_large/ Cheers, Karl.
  20. Just read this Nasa warns solar flares from 'huge space storm' will cause devastation - Telegraph . I am sure they are posting a worst case scenario - but I shall be ready with a manual PST and a big stick for when the power goes out and the raging mob spills out from the cities. I really must stop reading Post-Apocalypse fiction, I am sure its getting to me... Cheers, Karl
  21. Hi, Regarding Q1 - are you looking through the hole from a distance? I find that if I am too close then the image is definitely off because my eye is slightly off centre. Standing back helps. What is the view like with the focuser open (i.e. no eyepiece in it) - stand a long way back and see if the view is still correct. From what I have read, unless the secondary is REALLY off, it does not matter. If your really concerned about slop and being off centre then albedo0.39 has recommended a self centering adaptor which is here (flo don't stock it). Q2 - try to ignore the spider and don't try to line up with it. Your looking for the reflections in the very centre of the image. This guide has some quite nice clear images (Collimating Newtonian Optics) in particular this image (http://www.oarval.org/c-start.jpg) and notice that the spider is not mentioned anywhere. Just the cheshire cross hairs and the reflection of the cross hairs are important. [Although the author does mention centering the secondary - others with more experience than me have said its not really important unless its way off]. Q3 - if its the same as mine its a grub screw to keep the "mirror" part of the cheshire in its tube, seems to do nothing else. Cheers, Karl.
  22. I am a novice at manual (just migrated from goto). For me the biggest breakthrough was switching from a "normal" right angled finder to a corrected image using an amici prism. I am sure that once I am experianced enough I can handle the correction between view and map, but as a novice its been a HUGE help to see the same through the finder as I see in the chart. And a telrad to find the guide star. I think again that the more experianced can get by with just a red dot finder someone at SGL5 (16" lightbridge - cant remember the name - but I am sure you know who you are!) was knocking off obscure NGC galaxies with just an rdf and the eyepeice and very quickly. Just my tuppenth. Cheers, Karl.
  23. I have to admit to quite liking a good conspiracy threory, so I tend to need to have the conspiracy disproved and these two pages on wikipedia do that pretty well for me Moon landing conspiracy theories - Wikipedia, the free encyclopedia and Moon landing conspiracy theories - Wikipedia, the free encyclopedia. So for me its "hoax not proved" - so we went.
  24. The Night Sky Observers Guide (two volumes) George Kepple & Glenn Sanner. Its certainly not a field guide, but has very good descriptions of about 5000 objects with comments on the appearance in scopes from 2" to 20".. Lots of sketches give you good *realistic* idea of what your hunting for. Sky and Telescope "Pocket Sky Atlas" perfect for my 8x50 finderscope.
  25. Regarding the effect of lack of collimation at different degrees of collimation see here Thierry Legault - The collimation. Regarding a collimation tool (assuming your refering to a newt/dob).. Yes, a cheshire! With lots of thanks to albedo0.39 to for setting me on the right path. I struggled for a long time with an expensive (Kendrick) laser and never got good collimation, once I was shown how to properly collimate with a cheshire its much more efficient. Problem with a laser is that any slop in the mounting (and there will be) means you can not be sure of the centre being hit and you have to be correct to within a millimeter with the laser to get good secondary alignment. (Some lasers like the hotech try to aleviate this - but there are other moving parts in the focuser not just the compression ring and you need to be sure that the laser itself is properly colluimated). Cheshire is much better for this once you understand how to use it properly. Alignment of the primary can be done either wilth a barlowed laser or the cheshire again. I think albedo0.39 has a presentation on how - try to pm him, or get along to a club as its much easier if you have a guide the first time. Cheers, Karl.
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