Kurios Posted August 6, 2021 Share Posted August 6, 2021 I think I mentioned somewhere else in this forum that I have acquired my late father-in-laws telescope. He was a solitary astronomer venturing no further than his own garden with his 70mm f7 skywatcher telescope and a small pile of astronomy books. I never really knew how deep or not he got, he was a quiet man, happy in his own company. Anyway I haven't used the scope yet as we have yet to find the eyepieces. However I did have a closer look at the scope and the lens, mirrors and tube are all in great shape. Every joint, screw and bolt was lose however. The mount was dreadfully wobbly, the fine tuning diial (Im, sure it has a name but its the steel bar with a threaded screw to finely lift the scopes declination that runs parallel to the tube ) was very lose and wobbly so I cant imagine how on earth he was using it. So a bit of t.l.c and its now all nice and tight and feeling like a proper scope. Just need to find those eyepieces. If my reading is correct this type of scope only just qualiifies as a decent telescope, being considered the lower end of a beginners telescope and to be honest it wouldn't be my first choice. However for first telescope a free 70mm f7 refractor telescope is probably preferable to a £300-£400 200mm dobsonian reflector (what I really fancy) Commonsense prevails though and I know to hang on to my money til Ive got a bit of experience under my belt.. Cant wait til I get some eyepieces and a clear night, preferably on a weekend 😁 Link to comment Share on other sites More sharing options...
Nightspore Posted August 6, 2021 Share Posted August 6, 2021 Is it this one? Never underestimate a 70mm refractor; you'll be surprised what you can see through them. They'll equal a reflector of a 100mm and deliver a sharper more contrasted image. Kurios 1 Link to comment Share on other sites More sharing options...
Kurios Posted August 6, 2021 Author Share Posted August 6, 2021 Not that one. This is it. https://photos.app.goo.gl/kkzMwnq9ZLbUnZz36 Link to comment Share on other sites More sharing options...
Nightspore Posted August 6, 2021 Share Posted August 6, 2021 (edited) 49 minutes ago, Kurios said: Not that one. This is it. https://photos.app.goo.gl/kkzMwnq9ZLbUnZz36 Synta repackage these scopes so often I'm guessing it probably has the same optics, if not the same OTA. They abandoned the blue OTA paint scheme a few years ago for the 'Black Diamond' and some entry level scopes just got plain black. No doubt there's a Celestron or Orion version. The achromatic doublets are pretty well colour corrected though. My ST80 still gets out, albeit with an aftermarket focuser. Up to about 50~60x chromatic aberration isn't a real problem. For high lunar/planetary magnifications an inexpensive filter stack can help. The yellow filter takes out some of the cyan hazing. It's an old achromat trick. Synta achromatic doublets are remarkably good quality for the money. Add a better focuser and they can be quite rewarding little scopes. Edited August 6, 2021 by Nightspore Kurios and +Glafnazur 2 Link to comment Share on other sites More sharing options...
Kurios Posted August 6, 2021 Author Share Posted August 6, 2021 https://1drv.ms/u/s!AiTbyDPLii4kimoUAPFSwfi4Kp4X Not sure if these links arw working. The guide to how to share pictures is a bit vague. 😬 Link to comment Share on other sites More sharing options...
Nightspore Posted August 6, 2021 Share Posted August 6, 2021 I use Imgur but I think you can directly upload a file. I'm guessing your scope (I can see your picture in the link) is the 70mm, f/7 OTA doublet refractor Synta have been making for years. They just re-brand it occasionally. I have no personal experience of that scope but I have of small Synta achromats like the ST80. At f/7 I don't think chromatic aberration will be a huge problem. I'll bet money that you will be able to see the Cassini Division in Saturn's rings. If you have an Apple or Android device Celestron SkyPortal is a great freeware app. Kurios 1 Link to comment Share on other sites More sharing options...
Kurios Posted August 8, 2021 Author Share Posted August 8, 2021 (edited) I have now located the eyepieces for the telescope. There's a couple of them and a barlow lens (almost certainly the original pieces that came supplied with the telescope) Plus a black plastic triangular piece which I suspected was missing from the tripod. So fingers crossed for some clear skies, lets give this scope which has been sat gathering dust for the last 6 years a new lease of life. Edited August 8, 2021 by Kurios +Glafnazur 1 Link to comment Share on other sites More sharing options...
+Glafnazur Posted August 8, 2021 Share Posted August 8, 2021 I'm glad you found the eyepieces Karl, good luck and let us know how you get on. Kurios 1 Link to comment Share on other sites More sharing options...
Kurios Posted August 8, 2021 Author Share Posted August 8, 2021 Just come, inside, its starting to cloud over now, but saturn was looking splendid the rings where nicely defined! My 9yr old really enjoyed seeing saturn too. 😁. Jupiter was really nice too with the moons nice and clear and more spaced out than I'd anticipated. To the north fairly low was a star that through the scope looked both red and green/blue. Not sure what that one was, going to have to look it up. Nice first play with the scope though. Link to comment Share on other sites More sharing options...
+Bino-viewer Posted August 9, 2021 Share Posted August 9, 2021 Maybe that star was Capella in the constellation Auriga ? When a bright star like that is low down, and you observe it with a scope you are looking through a lot of atmosphere and its all this air and pollution that causes these colours you see as the light from the star is refracted giving the star a twinkling effect. Brightest star Sirius which we see in winter months is the perfect example. Its so bright you can see it twinkling and see red and blue with the unaided eye. Good to hear you had some nice views of Jupiter & Saturn 🔭👍🏼 Kurios 1 Link to comment Share on other sites More sharing options...
Kurios Posted August 9, 2021 Author Share Posted August 9, 2021 Thanks Bino-viewer. I did a quick google search last night that returned the same atmospheric explanation. I'll check out Capella and see if that was what I was looking at. I'm learning with every short sesssion 👍 Link to comment Share on other sites More sharing options...
Nightspore Posted August 9, 2021 Share Posted August 9, 2021 19 hours ago, Kurios said: Just come, inside, its starting to cloud over now, but saturn was looking splendid the rings where nicely defined! My 9yr old really enjoyed seeing saturn too. 😁. Jupiter was really nice too with the moons nice and clear and more spaced out than I'd anticipated. To the north fairly low was a star that through the scope looked both red and green/blue. Not sure what that one was, going to have to look it up. Nice first play with the scope though. Sounds great. I got 140x on Jupiter last night with my 72mm refractor. Jupiter's often a difficult target to get high magnifications so the seeing must have been well above average. Although it was cloudy with some humidity. I think that star in the north has a good chance of being Capella. Kurios 1 Link to comment Share on other sites More sharing options...
Kurios Posted August 9, 2021 Author Share Posted August 9, 2021 56 minutes ago, Nightspore said: Sounds great. I got 140x on Jupiter last night with my 72mm refractor. Jupiter's often a difficult target to get high magnifications so the seeing must have been well above average. Although it was cloudy with some humidity. I think that star in the north has a good chance of being Capella. Thank you, that link on "seeing" was very interesting,. Its not something I'd come across before beyond atmospheric turbulence. Nice. Link to comment Share on other sites More sharing options...
Nightspore Posted August 10, 2021 Share Posted August 10, 2021 5 hours ago, Kurios said: Thank you, that link on "seeing" was very interesting,. Its not something I'd come across before beyond atmospheric turbulence. Nice. The most famous seeing scale is probably this one. A 70mm doublet will cool down in just a few minutes, if that. A 150mm, f/6 Newtonian can take around 50 minutes to cool down properly. There is a large volume of air in the tube. If you de-focus on a bright object in night time you can actually see the swirling air currents inside the optical tube assembly. Kurios 1 Link to comment Share on other sites More sharing options...
Kurios Posted August 10, 2021 Author Share Posted August 10, 2021 6 hours ago, Nightspore said: The most famous seeing scale is probably this one. A 70mm doublet will cool down in just a few minutes, if that. A 150mm, f/6 Newtonian can take around 50 minutes to cool down properly. There is a large volume of air in the tube. If you de-focus on a bright object in night time you can actually see the swirling air currents inside the optical tube assembly. Thank you again! Thats very useful and interesting. 👍 Link to comment Share on other sites More sharing options...
Nightspore Posted August 10, 2021 Share Posted August 10, 2021 6 hours ago, Kurios said: Thank you again! Thats very useful and interesting. 👍 You're welcome. All scopes have varying cool down times. As a whole refractors fare better than reflectors. In my experience Newtonians cool down a bit faster than catadioptric scopes. Probably as they are open ended. Although size is the predominant factor in cooling times. My 90mm and 102mm Mak's can take around 40~50 mins depending on overall ambient temperature. The 127mm can take over an hour . My 235mm (9.25") SCT can take two hours or more. A 102mm doublet refractor like my Altair Starwave can reach thermal equilibrium in under ten minutes. Usually by the time it is in the mount with accessories added it is cooled enough to use. Kurios 1 Link to comment Share on other sites More sharing options...
Kurios Posted August 10, 2021 Author Share Posted August 10, 2021 My telescope is stored in the garage, so it should start off closer to the outside temperature. Although obviously there will be some differencec especially as there is a chest freezer in there, warming it slightly Link to comment Share on other sites More sharing options...
Nightspore Posted August 10, 2021 Share Posted August 10, 2021 Storing things outside is a solution. A 70mm doublet shouldn't have any real cool down though. My 72ED is good to go by the time it's in the mount. Kurios 1 Link to comment Share on other sites More sharing options...
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