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Showing content with the highest reputation since 04/06/12 in Blog Comments

  1. 8 points
    As requested, a photo of the finished clock. I'll be adding details of the construction shortly, copying relevant excerpts from my rather long thread in the DIY Astronomer forum. It's not really a blue moon, it's lit with a white LED but the digital photo has coloured it blue
  2. 7 points
    Always nice to see a bit of proper science. If youre interested another quasar is up for grabs now, just as distant (~8bly). If you havent already imaged it, its the twin quasar: The edge on spiral is NGC3079, really useful as a pointer to your target. Its also a great example of gravitational lensing.
  3. 7 points
    I have to say I almost entirely disagree with your 'ultimate guide' for beginners! All the telescopes you 'recommend' are very small aperture and in the main come with lightweight unstable mounts that will do more to frustrate the user rather than give them a good start in observational astronomy. For visual observing, aperture counts. The larger the diameter of your objective, the more light you gather on deep space objects and the more resolution you have on solar system objects. For the budget conscious beginner, by far the best bang for your buck comes with a Dobsonian mounted Newtonian reflector. Not only does a 6" or 8" Newtonian give great views of all classes of astronomical object, but it has the added advantage of a very stable, intuitive, low maintenance mounting. As for advising against a reflecting telescope as they are 'hard to manage', this is plainly wrong. Would you advise someone against playing the guitar because you have to tune the strings? Just as you can get pitch-pipes to aid in tuning a musical instrument, so you can get a Cheshire eyepiece to aid in aligning the mirrors. It doesn't take more than a few seconds and is nothing to be scared of. For those wanting to make a start in astrophotography the advice of 'don't because it's difficult' isn't at all helpful. There are many wonderfully helpful and encouraging imagers at SGL who are more than happy to advise how to get started.
  4. 5 points
    Half round file Stu- one with fine teeth and gently and patiently- very easy to catch the edge and bend it. Here it is in the spider- I’m about to fit it to the tube- hope I didn’t mess up any measurements
  5. 5 points
    Hello Gina I did a presentation to a Scottish Photographic Society a couple of weeks ago - Powerpoint based. Its attached - feel free to bin it, rip it shreds, do anything you want with it. I dont get prissy about copyright of my images etc - feel free to use any images you might want etc etc. All the astroimages are mine and the none astro ones are all copyright free. Astro Imaging presentation.pptx
  6. 4 points
    I'll start with some photos of the observatory taken a few years ago. From the north looking roughly south and then from the south at various angles.
  7. 4 points
    Following getting my 3D printers confused in Firefox and changing settings on my Mini printer, which was printing the bed clamps of Concorde, instead of the Concorde web site and messing up both print and Mini printer, I decided I'd print the parts on Concorde. So now I'm printing the second bed clamp on Concorde itself. Hence I now declare Concorde as a working printer even if it isn't finished!
  8. 4 points
    Pond filled. More back filling with soil. Now having a rest! Some photos.
  9. 4 points
    It's empirically verified that the speed of light in a vacuum is a universal constant, independent of reference frame. There is no analogous principle for sound waves. Hence one cannot attempt to reframe special relativity using sound, or any other form of energy transfer apart from radiation.
  10. 3 points
  11. 3 points
    Moved it to D6- that did the trick. think it should be strong enough 30D8DFF2-43AC-478B-AA75-B980CEC1CC78.MOV
  12. 3 points
    Hi Gina, I did a lot of professional public speaking in my career and have couple of thoughts based on what you have said so far. Given this audience is not astro people - I think I would first engage their interest by first talking about something they will understand - terrestrial photography. Hence, describe how a DSLR camera works first. Hence; reverse thes two slides Explain how terrestrial images are typically done with short exposures and how that works fine. Then explain that longer exposures and adjustment to ISO are necessary to capture enough light for evening pictures. Then it is natural progression to quickly explain how more extreme long exposures (or stacked long integration time short exposures) are needed to do astrophotograpy . Then mention how daytime images can get blurred if you are trying to capture an image of a fast moving car. Then, only after people have grasped these essential camera basics, explain the rotation of the Earth and the impact that has on long term exposures and the need for tracking and or guiding. If you offer this same information the other way round, I don't think many in a broad audience will adequately make the link between exposures, earth's rotation and 'star trails'. However, if you reverse this, it becomes a far more logical progression of information. Just my two-pence worth....
  13. 3 points
    Finished clock except for the motor drive unit - tested with a DC motor-gearbox. Arduino Nano arriving tomorrow. The one I had was faulty.
  14. 3 points
    Here is a photo of the lampholder and LED bulb (G9 base). There are two fixing holes 0.5" apart (12.7mm) a bit bigger than 3mm (probably 1/8" = 3.175mm) so M3 bolts will suffice for fixing (one is shown in the photo). The LED bulbs are 4W, equivalent to a 40W GLS bulb and 5 of them will give plenty of light. They are the dimmable variety so I will be able to reduce the light output for watching television.
  15. 3 points
    Went out this afternoon and had a good look at the area to determine where to put the new "pond" and fountain/water-feature. There's a wide view through the picture window in the living room so decided to put it away from the other pond and bird feeder between the new micro observatory and main one. Started a bit of planting round the naturalistic pond too. Some photos from indoors as it's raining.
  16. 3 points
    Taken from living room window. Pond is level - ground slopes. So does my bird feeder - must re-plant that upright ? Another lovely sunny day with a few clouds about. I'm doing what I can before it gets too warm - 23°C forecast for today. Stopped for a mug of coffee ATM.
  17. 3 points
    And if it doesn't you can always use it for waterskiing ? James
  18. 3 points
    Print finished and looks virtually perfect. Printing time 1h 23m. The 300mm steel rule shows the scale. That print is BIG!!
  19. 3 points
  20. 3 points
    Congratulations on your new mount. I am sure that you will soon get used to the set up and it will become second nature. A lot of folks are using these Polemaster thingies now for polar alignment. I know exactly what you mean about storage. You may find these azimuth bolts awkward when storing too. However, there is a simple solution to the storage problem. It inolves building a shed in the garden with a roof that rolls off ..... well ... you know the rest....
  21. 3 points
    Hi Mountain Skies Your blog is an interesting personal point of view on starting out in astronomy and I think you make some useful points. Personally I don't agree with you regarding getting a cheap refractor as a good first scope. A nice little Newtonian on a decent tracking mount (EQ5 for instance) or on a Dobsonian mount would be my preference. Regarding your comment "The biggest problem you hear in astronomy is that someone got a big 1000 dollar telescope and hated it and stuck it back in his/her closet." Whilst people having "all the gear and no idea" can be an issue, from my experience, a MUCH more common problem is people getting a really cheap scope (with a shoddy mount), and this putting them off the hobby. Members of SGL have between them thousands of years of experience of many aspects of amateur astronomy. Quite a number of members are also professional astronomers. The strength of the forum is that there is a vast range of experience within the membership, yet I somewhat doubt any member would ever claim to be the' ultimate' authority on any single aspect of the hobby. Perhaps billing your blog as an 'Ultimate guide' is over-egging it. Might your blog be more appropriately entitled - 'Starting out in astronomy - a personal view'?
  22. 2 points
    Second time lucky- I ordered some ss mudguard washers and turned them to size this time and the soldering went perfectly I also discovered that the citric acid I bought to descale my kettle works great for removing borax flux Just need to not make a balls up of bending the edge over now...
  23. 2 points
    Brilliantly written David. Reminds me of my last holiday in the Lake District where there were really dark skies too, and like you I had a car full of not only my family and luggage; but Wiggins our dog too! I don't have a smaller travel scope so couldn't take anything with me, although I wish now I'd just taken a pair of binoculars. The skies were brilliant, and just like you mentioned, I remember standing out in a field staring up at the skies just making out all the constellations, until I heard the eeriest loud noise I've ever heard. I can only assume it was a fox, but it was so strange I really couldn't make out if it was from an animal or a human! Certainly it was enough for me to decide I'd probably spent long enough standing in the dark in the middle of a field by myself. (I think I would have been out all night though if I'd had my scope with me). Thanks for posting it was a great read.
  24. 2 points
    Butchering an old web cam? Thats the spirit! Looking forward to seeing the results. Yes. Something to hold the phone in place helps. There have been loads of threads on this over the last few days. I think that one cropped up for sale the other day in the classified section. I’m attempting a home made solution.... Paul
  25. 2 points
    I have just done another talk on Monday to a huge U3A audience (over 200 people). I was told a lot of the photographic group had turned up too. I did my usual talk which included what, and how to create images. I think one or two people dropped off to sleep, or glazed over, but the majority seemed to find it very interesting. At the end I took a stacked image (old Horsehead DSLR image) and live processed it. I got some very interesting questions afterwards, and one person turned out to have done a bit of AP himself. I got another booking on the back of it for a Probus group. If you would be interested I might have a PDF copy of my talk somewhere I could e mail to you for ideas, I sent it to some-one else asking a similar question, assuming I can find it. Carole
  26. 2 points
    I regularly do talks on Astrophotography, and do it with Powerpoint. I normally start at the beginning and say what kit is needed and why, and what happens if you don't use an Equatorial mount etc. Then I have a prepared number of stacked images showing the improvement the more that are stacked. starting with a single sub, then 2, 4,8, 16 stacked, and then show the whole image 50% single sub and 50% 16 subs stacked showing the huge difference. That always brings some Oohs and Aahs. An example of an image processed without flats, then the stretched flat for that image showing the dust and vignetting, and then the image with flats applied. More oohs and aahs. I show how to focus with a Bahtinov mask, and topwards the end of the talk I show a few of my images and how long they took in exposure. HTH Carole
  27. 2 points
    I have decided to get the ZWO ASI 120MC-S from FLO. I feel a bit "lost" without the ASC image to look at! If this camera turns out not right for my ASC I can use it for planetary imaging later as I have in mind. My standard widefield imaging rig is taking priority though.
  28. 2 points
    Indi can control DSLRs via gPhoto https://indilib.org/devices/ccds/gphoto.html
  29. 2 points
    Here is a screenshot of the firmware check of the bed level which shows that the orthogonality is near perfect with the Z guiding perfect. The variation that remains is a slight bending of the glass plate as it is only clamped at two corners ATM - I have more clamps to print. I am amazed to have managed such a very small variation in height without any bed levelling, across a 400mm square. Less than a tenth mm RMS error. And this will be corrected by the firmware in printing.
  30. 2 points
    Umbilical support bracket. I'll explain how this will work later. This shows the print quality I'm getting from Concorde. Printed with a 0.8mm nozzle.
  31. 2 points
    You don't need a lot of space, we can't fit a pond in the garden ground but have a pond bucket instead. It is small yet has brought frogs to the garden and is very relaxing to sit next too. The bucket is one of those garden buckets you see Monty using on Gardeners World. We have frogs again this year and I am hoping the lily will flower. You will need to add an oxygenator I have used a British native one called starwort I bought cheaply delivered through the post (local garden centre had only the invasive non native species) and working with the lily pad leaves keeps the water clear and healthy. Lots of ramshorn snails in there and other interesting things. The duckweed gets fished out when it accumulates.
  32. 2 points
    Messing around with different stretch functions I came across one that gives a very direct visual meaning to stacking subs. This is exactly like the pile of acetates I used to prepare my classes on... Interesting to see that a median stack destroys the effect completely: It makes sense when you think about it, but all the same I was quite surprised at the difference in information content between these two ways of combined subs (at least at the edges where it is most noticeable since the number of subs contributing varies).
  33. 2 points
    Assembled dome and casing top etc.
  34. 2 points
    Actually, the rain stopped and the sky cleared a bit just before midnight and I was able to capture an image a couple of seconds before midnight and another 3m into 2018. There are a few raindrops on the lens. HAPPY NEW YEAR everyone
  35. 2 points
    Skirt and lens tube extended and taper increased slightly to improve clearance.
  36. 2 points
  37. 2 points
    On the right speakers Organ music sounds stunning.
  38. 2 points
    Or should I have said "Clever cogs" ?
  39. 2 points
    I totally agree! Even for the short time that I've been astronomising (definitely made that word up!) cloudy skies has taught me the virtue of patience. It's a nice way to look at it @Pig and @Littleguy80, that it's even more special when a clear night comes along.
  40. 2 points
    I never paid much attention to the weather forecast until I got my telescope. It's very sad at the moment with little hope on the horizon for a good clear night. I do, however, agree with @Pig. If it was clear all the time then it would be easy to take it for granted. It's the evenings spent reading forum posts, books and planning the next session that all add to the excitement when the clouds finally do clear. The only problem I have is that I then try to fit 3 weeks worth of viewing into 1 night! Especially difficult with the short summer nights!
  41. 2 points
    We do seem to have had more than our fair share of clouds over the past couple of years and it can be a tad frustrating. However, I feel the clouds do prevent this wonderful hobby from becoming tiresome as we appreciate the clear nights, and days, when they eventually come along. Imagine how horrid it woul be to have wonderfully clear conditions on tap !!!!!
  42. 2 points
    That title confused me, was expecting this Dave
  43. 2 points
    Got my first glimpse of it tonight. Grand isn't it?
  44. 2 points
    Absolutely right. In addition the speed of sound varies even within an inertial frame, it changes literally with the weather. Regards Andrew
  45. 2 points
    As a rough guide so far: 22" blank £475 10kg weight disc £20 3kg 60grit £30 3.5kg 80grit £15 1kg 400grit £13 1.75kg 220grit £12 Spirit level £8 Gorrilla bucket £12 Belling stones(6!!) £10-15 12.5kg 80grit £50 Still have 10kg of 80,all the 400 and 1kg of 220 left
  46. 2 points
    No, keep at it. If you seek professional help you'll be wasting scope money.
  47. 2 points
    These are amazing. You are truly gifted, my friend, both literally and artisically. A real pleasure viewing all of these sketches and it makes me think if that is how good the views are in a dark sky with a 10" what on earth would I see in my 14". I just might have to make some plans of my own. Thanks once again for putting these together, you did an amazing job.
  48. 2 points
    Excellent sketch, Col and the attention to detail and shading is outstanding. Lara is certainly coming up trumps. I personally feel it might not have been such a bad thing that the planned night didn't work out. I feel that a good night with the mistress on a single object or two, paying attention and trying to tweak from the given image the best we can is a lot more fruitful than a run around twenty objects without much care or attention. I don't know if it helps, but I don't really bother with a rubber. I 'sketch 'blind' with very little light and so what I have found helpful with Jupiter is instead of pencils, a reasonably thick blending stub. I load the corner of the page or a spare slip of paper with graphite from a 4B or 6B and gently tone in what I am seeing. Anyway, thank you for sharing your art work and informative report and I look forward to more.
  49. 2 points
    I've just reported you to the security services as I think that's a surface to air missile in disguise....
  50. 2 points
    Thanks, Ken. Let me know how you get along. I think I'll pop up on the roof tonight, the first time in over two weeks!
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