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brantuk

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brantuk last won the day on December 26 2015

brantuk had the most liked content!

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About brantuk

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    Hyper Giant

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    Leicester
  1. brantuk

    David Lukehurst

    I've met Peter Drew many times at star parties - a lot of folks don't realise how significant he is in the world of astronomy, mostly because he's such a nice and modest chap. But you get talking to him and find out about the stuff he's done and you'll be fascinated. I was very flattered the first time he came to look at my solar scope when it was a new model.
  2. If you have the counterweight system on the scope and you remove one of the cameras from a well balanced system - then you need to rebalance it all. I think it may only be a matter of moving the counterweight along the bar an inch or two. If that doesn't work then you could try sliding the frac up or down the dovetail bar. Hth
  3. brantuk

    Another rant at other social media sites

    I don't think of SGL as a social media site - for me it's a specialist hobby forum where we come to acquire and share knowledge, and chat about anything to do with the hobby with like minded people. It's also a place to arrange national and local meet ups with fellow hobbyists. Social media sites like FB, Twiter, Instagram, etc are much more general and comments can be passed about almost any subject, even if you don't know what you're talking about, nor who you are talking with. You can also display meaningless pictures of a lame life and people you will never meet or know will like you by clicking an icon on a computer screen and retweeting your post until the whole world knows how inane you are lol.
  4. With cheaper scopes, there tends to be less emphasis on "figuring" of the optics and quality of glass/mirror used - just the bare minimum to justify the notion it's a telescope, and they slap it in the tube, often with poor fixings, and pop it on a low quality wobbly mount/tripod. Seben have done a lot of this in the past and their scopes have needed so much modification you may as well have spent the money on something that works outa the box. Imho they're ok as project scopes, or for kids to dabble in the hobby without spending a ton. But if you want a trouble free scope from the get go, up the budget a tad and get a SW 130P. Hth
  5. brantuk

    Newbie question

    The bright one is a star - all stars are dso's. The smudge below could be a more distant star or even a nebula - again both dso's. But it is deffo out of focus. The general shape and orientation in the sky could suggest M42 (Orion Nebula) under Alnitak - but really there's not enough info in the pic to be sure - unless you know you were looking at the constellation of Orion. (Download Stellarium - it's free and a great way to know where you are looking in the sky - welcome to SGL)
  6. Here you go: https://www.365astronomy.com/The-Night-Sky-Star-Map-Celestial-Constellations-Umbrella-BLUE.html?gclid=EAIaIQobChMI_bvJ77vR2QIVqLXtCh0ltQcVEAYYASABEgJnmPD_BwE
  7. As above - but also make sure it's well ventilated to avoid condensation build up inside the scope - especially in your C925. I've seen water swilling around inside the tube of Mak's and Sct's and it's a devil to get out.
  8. Hi Paboy and welcome to the forum. The answer to your question is double edged I'm afraid. Telescopes only gather light and focus it - they don't necessarily enlarge it. The larger apertures will gather more light than smaller apertures and their ability to focus depends on the focal length and focal ratio of the scope (amongst other attributes). For seeing close objects like planets you get a sharper, higher contrast view from longer focal lengths and higher focal ratios (e.g. an f-12 Maksutov with 1500mm focal length). For seeing objects deeper into space, a low focal ratio and wider aperture is more important (e.g. f-5 dobsonian with 16" aperture). To "enlarge" what you see in the scope we use eyepieces of different focal lengths and magnifications. Magnification is given by scope focal length divided by eyepiece length. So a fl=1000mm scope with a 10mm eyepiece will magnify 100x. We also use barlow lenses typically 2x and 3x to further multiply the magnification factor. How far you can go with magnification depends on the atmospheric transparency and how "clear" the weather is - what we call "the seeing". When it comes to photography however, this is mostly done at the prime focus of the telescope, and you are looking for a scope that focuses two or more wavelengths of light at the same focal point to achieve good colour. Also desireable is as flat a field as possible, little or no chromatic aberation, and coma free. Then it comes down to image scale and how many pixels are used to record the photons of light being captured by the camera. Telescopes with lower focal ratios will gather light faster than those with longer focal ratios - amateur astro imaging tends to be done around f-5, preferably with the clarity/contrast provided by refractors, though some use reflectors as well. The focal ratio determines how long it takes to capture an image, lower fr = faster capture and requires lower exposure times. Magnifying adaptors are sometimes, but rarely, used. I would recommend a good read of AP imaging principles before getting a scope/camera combination. And do go along to your local astro soc where you'll get loads of advice and see examples of equipment used for both observing and imaging. A good book for amateur AP is "Making Every Photon Count" by Steve Richards.
  9. Pop a "Want Ad" in the classifieds "For Sale or Swap" is your best bet. Totally agree the best scope is the one you use. Welcome to the forum!
  10. brantuk

    TAL 100R price?

    £150 'ish would be a good average depending on age and condition and negotiating skills.
  11. Yes it's a shame the car parks are locked overnight at Bradgate - same at Beacon Hill too. I usually run out to Wymeswold to meet up with the guys at EMS. I occasionally go with Leics Astro Soc to their dark site near LFE - though I'm not sure where their current site is exactly. If you need any details let me know and I'll happily dig them out and PM them to you.
  12. brantuk

    Buying 2nd hand eyepieces

    Whatever eyepiece you buy check it will give you the width of field you require and the correct magnification you're after. You should also beware of eye relief and also think about the size of aperture you'll be looking through. We all see differently (including people who wear glasses) and you really want to ensure the eyepiece fits you personally as well as your scope (or scopes if you have more than one). I always check the technical specs on a retail site first and estimate the used price to about 50% to 70% of the "new" price depending on age and condition. Bear in mind some folks will build in a little leeway for negotiation, especially if you're buying more than one item from the seller. You can also ask about the condition of the rubber eye guards, and how it's been cleaned and how often. Pay special attention to the coatings too. Good luck.
  13. You may want to consider buying or making some library steps for your son. If you make one then you can pick the weight, materials, and number of steps, as well as the width/depth of each step to provide a solid platform for him to stand on. Something like this can be very useful - even for some adults (who I have seen using them): https://www.google.co.uk/search?q=library+steps+with+pole&dcr=0&tbm=isch&source=iu&ictx=1&fir=cnqRbqX3SsQNJM%3A%2CvEnHleTN8tNswM%2C_&usg=__mFe3-4DBpzPg4cOoi_RnpQOnoBE%3D&sa=X&ved=0ahUKEwjK9JS_prLZAhVFNMAKHTArDIIQ9QEILTAC#imgrc=qmOXhN4Ee3OZkM: Also - a shroud is easy enough to run up from thin camping foam or black material - so don't let it put you off the truss design. A 130 offers more light grab than the 100 and will give access to more and deeper space objects, and better contrast and clarity on near space (planets etc). Hth
  14. brantuk

    newbie

    For the first manned space flight to the moon, NASA didn't know much about the moon and where was a suitable place to land. So they asked Sir Patrick Moore about the moon and what he thought about where to land, because he was the leading authority in the world who had studied the moon more than any one else at that time. Indeed he was NASA's main consultant for the moon landings at the time. And as Geoff says above, that knowledge has developed a lot since the actual landings. So I would think both sources of information are going to be useful.
  15. Telegizmos are amongst the better scope covers certainly. They're great if you're at a star party or some other temporary dark site for a few days. I personally wouldn't leave a dob out permanently though. The metal and mirrors would be fine so long as you don't get any insects all over them. But my concern would be the wood, wide temperature changes, condensation, and damp. The smaller dob bases tend to be chipboard which can warp if any moisture gets in. Keeping them indoors or garage/shed would be far preferable imho.
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