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cloudsweeper

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About cloudsweeper

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    Sub Dwarf
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    Male
  • Interests
    Physics, maths, history (family, military, social), pre-modern architecture.
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    Merseyside, England

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  1. I use a Revelation 2" 42mm/65deg with my 8SE, which gives around 1.34deg FOV and exit pupil 4.2mm. I haven't bought a 6.3 reducer, because of the problems reported with them (visual use), especially for EPs of more than about 24mm focal length. Concerning the issue of brightness, these are my thoughts: Consider say a 30/82 eyepiece in the telescope. At f/10, you'd get x68 @ 1.21deg, with exit pupil 3.0mm. At f/6.3, you'd get x43@ 1.92deg, with exit pupil 4.8mm. Now exit pupil gives a measure of perceived surface brightness, so the increased exit pupil might lead one to believe there is greater "brightness". But surface brightness itself is not enough, and overall brightness depends also on the size of the image. A larger image is perceived as being brighter, and with the reducer in place, the actual mag has gone down, so that brightness might therefore be about the same. (The full analysis of this is, I suspect, somewhat involved.) As @TimB says, it is complicated, and you can delve as deep as you want, or just take the pragmatic approach and see what you get with a bit less emphasis on the science! Doug.
  2. Commenced about 10.30, aligning the 8SE on Arcturus and Vega. NGC 6871 open cluster - several stars, loose array, centred on two close pairs. IC 4996 open cluster - similar to the above, centred on a close group of three stars. It was however not very dark, so I returned to these after midnight and the difference was quite pronounced. Many more stars were visible, but NGC 6871 was marginally more attractive for having more fainter stars on show. An increase of mag to x85 was beneficial. I then targeted the Cygnus Star Cloud (Tulip Nebula, Sharpless 101) by hopping there from Eta Cyg, having used designation SAO 069116 for the GoTo, but I could only see a few of the brightest stars, and no concentration of stars or nebulosity. However, moving 2 deg north, there is a pleasing starfield centred on six bright stars in a line with a slight bend half way along it. To finish, I entered M 57 the Ring Nebula into the handset. GoTo put it dead centre in the EP (giving x48 @ 1.34 deg), and the ring was clearly seen - especially using AV - and focus was aided by the many close stars in the region. A very enjoyable session, despite the fairly light and cloudy sky. An FOV full of stars never fails to delight! Doug.
  3. Study the handbook carefully then be sure you have entered lat/long, date, and time correctly. When aligning, it's better to use higher magnification, but when looking for something via GoTo (or otherwise), it's better to use the lowest mag you can. (If you use high mag at this point you can easily fail to see your target.) One other thing - until you find your feet, try a one-star (or planetary) alignment, and use GoTo on a nearby object. It should be very close. Doug.
  4. I use a "star simulator" to collimate my SCT in daylight. It consists of a piece of thickish black plastic with a very small hole drilled through it, the hole then being filled with white DIY filler. I suspend this as far away as possible and then perform the collimation using the image of the small, round white dot. It obviously works well since a star test with the 'scope reveals nice concentric circles, and - in good conditions - all images are sharp and detailed. Simple, effective, and costs nothing! Doug.
  5. .........and there's still time afterwards for a nice relaxing drink (whatever your taste) before a sensible bedtime! Marvellous! Doug.
  6. I just keep looking and experimenting, and try to get the best out of a target. But DO keep a log. I have a list of objects to view (by constellation), and a log to record each session. And then I keep a list of what I've seen, arranged by category - M, C, NGC, IC, planetary, lunar, stars, etc.. Well worth doing - you can easily forget, with all treasures there are up there! Doug.
  7. It's good all year, but now it starts to get better! Doug.
  8. Exactly! My view of Saturn a few days ago through clear skies was stunning, and it was below 11 degrees. Get out and take a look, and there is usually something good, plus some surprises! Doug.
  9. Great going - you started off with a couple of beauties, and did well to see the Cassini Division first time out! There's plenty more out there, so have fun! Doug.
  10. During or after? Or both..... Doug.
  11. Good one, John - also its close relation Patience! Doug.
  12. I just have bats and hedgehogs! And the occasional owl. Doug.
  13. Yes Neil - we develop methods that suit us alright! I operate using the circles (4, 2, 0.5 deg) on Stellarium, plus a knowledge of the TFOV I can see (which I have on a handy table, along with the mag for each EP). Using the RACI finder (5 deg) can also help, especially as it gives magnification and light-gathering (unlike the Telrad). When not using Stellarium, like you I refer to the Pocket Sky Atlas, along with a clear sheet with circles (5, 1.5 deg) drawn on it. Doug.
  14. I don't mean great 'scopes and top-of-range EPs, but rather the extra add-ons, features, techniques etc. that really help the hobby along. A few come to mind (in no particular order): # aperture (8" max at present; 12" at planning stage) # Stellarium (an enormous boon for showing then confirming targets) # averted vision (great for faint objects and elusive detail) # SGL (the information, support, encouragement, sharing, and humour that goes on is priceless) # a supportive wife (who tolerates the clutter in the house, the expenditure, and the excited blabbering after an observation) So what would other SGL-ers place in this category? Doug.
  15. Paz - great report of an interesting and memorable session. The points about observing these wondrous sights certainly strike a chord! And Yes, they are indeed small in the EP, yet can still reveal features and fascination. Doug.