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laser_jock99

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Everything posted by laser_jock99

  1. I had a look through my old images to see what sort of exposures I had used to capture the Horsehead. You basically don't need that long an exposure to see it. Using a 12" F4 Newtonian scope and unmodded DSLR @ ISO3200 I got this in 300 seconds Using a smaller 6" but optically faster F2.8 Newtonian scope and modded DSLR, i captured the area in 142 seconds.
  2. Some good shots posted so far of everybodies scopes 'at work'. Here is my 6" F4 Newtonian - the inset is the picture it was taking at the time. Another one of the same scope - all the red light is coming from the LED on the intervalometer!
  3. The fast F4 Newtonians are interesting scopes (I have four!) the caveat being that unless you love a really steep learning curve- they're not the best scope for starting out on. Collimation is fairly easily mastered- again the caveat is practice and the right tools to make the process fast and accurate. As others have said- the mount is fundamental, if you're already thinking about largish scopes then it might make sense to invest in the bigger EQ6 from the go. That way you'll be fairly future proof even if you start out with a small refractor. BTW- the Telescope House GSO/Revelation Astro F4 Newts are good value http://www.telescopehouse.com/telescopes/telescopes-by-brand/brand-revelation-telecopes/revelation-8-f-4-m-lrn-optical-tube-assembly-ota.html The monster 12" is steal at £575 but only really suited to observatory use.
  4. The 130PDS used with the ASA 0.7x corrector/reducer would give a respectable F3.5 / 455mm FL instrument. I have tried it with the 150PDS and it seems to work okay. Never going to be as portable as a camera lens though!
  5. If you want a portable F2.8 astrograph consider the 6" Boren-Simon Powernewt . Similar to my home cooked version but with most of the mods done for you.
  6. Hi Mark, Nant-y-Moch is a good dark place, plenty of places to pull in along that road. Ynyslas (nice place) is probably not that bad either (never been there at night though- although I might be tempted to night fish the beach at some point!). I keep my fishing boat down at the Ynyslas Boat Yard- which reminds me I had better go and fetch it soon as I'm unlikely to use it again till Spring..... LJ99
  7. Keep plugging away at it- mine took the best part of two summers to complete.
  8. Looks lik a solid job- I don't envy the guy who eventually has to remove it!
  9. I have had one a couple of years and find it interesting to see how much the readings can vary from session to session. Typically at the obsy site in Mid Wales 21.2 to 21.6 and rarely 21.8 I think a lot of this boils down to moisture/transparecy. On ultra clear nights the readings get lower- possibly because starlight is contributing to the photon count. It also depends on where you point the device- ideally the Zenith, but if The Milky Way is overhead you'll get a false reading. The SQM can also be used to evaluate sites on a cloudy night since they are very good at measuring the illumination on the underside of the cloud base. Interestingly from my obsy site on cloudy night I get a reading of >22 simply because there is no light either from stars or local light pollution. So the blackness of the clouds might be a better indication of light pollution levels? To illustrate the point see how bright the background sky is compared to the passing clouds in this video: Maybe we are measuring the wrong thing?
  10. Not much of collection to speak of really: Some Williams Optics 10x50 (nice views but military build quality means they are rather heavy 1.6KG!!) Swift 20x80 (again rather heavy & better used on a tripod) and a group of cheap 10x50's from Prinz, Bresser, Boots etc. These to be honest get more use because they are lightweight.
  11. What make of scope is that- looks very well constructed?
  12. Yep- nice 2" monorail focuser on these scopes. http://www.teleskop-express.de/shop/product_info.php/language/en/info/p4762_GSO-6--Imaging-Newton---150mm-Oeffnung-f-4---2--MONORAIL.html Not logs- but a bucket full bricks suspended below the tripod. I thought this was standard proceedure for imagers?
  13. .....enough of these 'fracs & Dobs. Let's see some proper scopes! My collection (so far....) 6" GSO F4 Newt 8" Cape Newise F5 Newt 8" GSO F4 Newt 10" GSO F4 Newt 12" GSO F4 Newt
  14. A badly mounted Newtonian that can't do AP.
  15. My Equinox ED120 & Starwave ED80 getting a rare outing.....
  16. Another good, easy test for evaluating a dark sky site is to look at the night time clouds. If they are illuminated from underneath by local light pollution sources then the sky will not be as dark as it could be. In the ideal situation clouds will appear as black shapes against a fairly bright night sky. This video from my observing site sort of illustrates the point- the clouds are noticably darker than the sky behind them, indicating low local light pollution. From the same site really high clouds (~35,000 feet) actually pick up light pollution from towns 60-80 miles further south. This contrail drifting through M8 and M20 in Sagitarius is clearly illuminated by distant sodium street lights.
  17. What you require is a low profile M48 to Nikon mount adaptor like this http://www.teleskop-express.de/shop/product_info.php/info/p6527_TS-Optic-ultrashort-Adapter-from-M48-to-Canon-EOS-EF-Bayonet---only-1-mm-optical-l.html ....but for Nikon. I found one but can't for life of me find a link for it! EDIT- the other possibility is a coma corrector with longer back focus distance like the Baader RCC 1 Newtonian Coma Corrector http://www.teleskop-express.de/shop/product_info.php/info/p6527_TS-Optic-ultrashort-Adapter-from-M48-to-Canon-EOS-EF-Bayonet---only-1-mm-optical-l.html
  18. Simply stunning, so much going on there I could study it for ages. If I had any criticism it would be a very minor one- the 'enhanced detail' areas like M42 don't seem to 'match' or seemlessly blend with the rest of image. It's like looking through a misted window with a few tantalizingly mist free bits! I guess there are no plans to image the whole area in detail and make a 4000 hour version!
  19. Spurious reflections are always a possibility with bright stars like Alnitak in the field of view (or even just out of it). The line could be from one of the other Belt Stars?
  20. If you get a Baader MPCC make sure it has been machined correctly. I had to send one back after I (eventually) realised it wasn't sitting orthoganally in the 2" holder when clamped up due to poor machining.......
  21. My old 60mm Tasco (and me some 25 years ago!)
  22. Newts are great IMHO- but there's no getting around the fact they need collimating before an imaging run. It needs to be do done but should not be more onerous a task than checking the focus with a Bahtinov mask for example,
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