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Everything posted by perrin6

  1. perrin6


    From the album: eyepiece for sale

  2. perrin6


    From the album: eyepiece for sale

  3. perrin6


    From the album: eyepiece for sale

  4. Isn't there reason to believe the moon reduces Earth's axial variation and without it the climate would have been more extreme and mass extinctions more regular and damaging ? Also don't we need the moon as a base for future journeys into deep space perhaps as a sort of 'insterstellar Heathrow'. Maybe push it away a bit to reduce the amount of light pollution it causes. Have to admit I do love old moonie.
  5. Have a try for M51 the whirlpool galaxy, I was amazed to see it through 15 x 70s under quite light-polluted sky, although it was quite close to the zenith which was a bit of a neck strainer.
  6. Colour in Jupiter is much more apparent once the atmosphere settles. Viewed Jupiter this morning from North Adelaide which is pretty light polluted and seeing steadied enough to see the disk as pinkish, the bands dark reddish-brown and Great red spot a strong orange. Jupe gets a bit higher here than in the UK, (it was about 45 degrees altitude) which helps. The colours are subtle with an 8 inch although my scope has a smaller than usual diagonal mirror and wire spider, which probably helps as these improve contrast a bit. This morning it looked it's best a little before sunup with the sky blue rather than black.
  7. 'The machine age' title track from 'Bicentennial man'. Builds to a climax and is technological, sciency with an ethereal edge. 'The cloud' from Star trek the motion picture, mysterious and a little spooky & dramatic. Brian Eno's 'Apollo' Mike Oldfield's music has some 'spaced-out' feelings eg 'The songs of distant Earth, 'Tubular bells'
  8. From the album: 200mm F6 backpack scope

    Breaks down to fit in medium-sized bag. Optics; GSO via Bintel, Australia. For use with light eyepieces only eg plossls, orthoscopics, RKEs etc Optimised for high contrast with minimal diagonal size (31mm), guitar string (.23mm) wire spider and v. low profile push-pull focuser made of plastic drainpipe lined with milk bottle plastic. Computer fan mounted on rear powered by 8 AA batteries. Optical tube Assembly weight; 11 pounds, Mount; 1.5 pounds.
  9. perrin6

    200mm F6 backpack scope

    optimized for contrasty images
  10. Being a 9-stone weakling I've made wooden dobsonians that are lighter and easier to manage than the equivalent metal-monster versions. My present 8inch weighs 12.5 pounds, the Optical Tube Assembly weighs only 11 pounds. Haven't tested it in a strong wind yet but it has a very low rocker box and thus a low centre of gravity Was it not Hamlet who said; 'Who would Fardles bear, to grunt and sweat under a heavy Dobsonian' ?
  11. A reason why it's good to have a small scope that one can 'chuck out' at a moments notice and will cool quickly to ambient temperature to take advantage of those fleeting glimpse nights.
  12. Hello Simona. I'm always concerned about those new to telescopes getting in too deep by buying one that is large, heavy, with lots of gizmos etc and getting quickly disheartened before they've experienced the joy and relaxation that a smallish, simple telescope can bring. I know nothing about astrophotography (AP) which is a great hobby as well as being of real value to science but I wonder if some people miss out on the simple pleasures of just looking. If your budget is tight you will obviously need to purchase a telescope than can be used for AP even if you only initially use it visually. The best value for money is the Newtonian and I think some people buy an inexpensive dobsonian, eventually mounting the optical tube on an equatorial mount so they can use it for AP. As to what size to get this is a difficult decision because of that accursed affliction know as 'aperture fever' although this is less of a problem for AP-ers than for visual observers. You will have to decide what is the largest you can manage physically, perhaps by going to a shop or a star party (I'm sure some people won't mind you trying to lift their 'scope), if you can get to one.
  13. perrin6

    my eyepiece case

    From the album: Non Astro

    This is where I keep my eyepieces (The middle one).
  14. perrin6

    Non Astro

  15. The most distant globular cluster I've seen was in the Andromeda galaxy as a tiny fuzzball making a triangle with two foreground stars. Used a map I found online and a 14inch under fairly light-polluted skies.
  16. Anyone know if there are cotton buds with no abrasive fibres like BPC standard cotton ? I don't like using a cloth to clean eyepieces, it's just too fiddly, especially on very small eye-lenses and field-lenses that are recessed a long way into the eyepiece body..
  17. I would suggest keeping them all and acknowledging to yourself that for some deep biological reasons we tend to regularly reassess our living space and possessions. Perhaps this is a remnant behaviour from when we were always on the move as hunter gatherers !
  18. perrin6


    From the album: 200mm F6 backpack scope

    parts cut out of 3 mm ply (BCB quality). This was done so I could cut circular parts without having to buy a router. All cutting was done with a stanley knife, circles made with a makeshift circle cutter employing a stanley blade. 4 layers of 3mm are used for the mirror box and mount. inner 2 layers of mount and inner 3 on bearings, will be skeletized to reduce weight, should still be strong enough. OTA will be about 11 pounds and consist of 7inch high mirror box, 35inch truss (12mm aluminium tubes cut in halves) and upper cage 1.1 pounds. I am mad enough to use a piece of pvc drainpipe with inner layer of milk bottle plastic as a simple push-pull focuser. This works fine on my 150mm F8 scope but will prove tricky to focus on an F6. Just couldnt find a low enough profiled focuser for the 31mm diag mirror to produce large enough fully illuminated field. (4mm - good enough for 6mm ortho which will be my main high power @ x200)
  19. perrin6


    From the album: 150mm F8 planetary scope (GSO mirror)

    15% obstruction (by diameter) of primary. .23mm wire spider produces visible on only the brightest of stars and the bright planets and spikes are quite unobtrusive
  20. Have had great views of Saturn, moon & double stars with this high contrast scope. Interestingly, although 100% field of illumination is only 8mm & light fall off is steep outside this, I had a v. good view of the great nebula in Orion, lots of contrasty knots and detail (using orthoscopic & RKE eyepieces) despite observing from North Adelaide. .23mm-wire spider & 22.5mm diagonal produces about 2.8% obstruction of main mirror by area and faint diffraction spikes only on stars & planets brighter than 1st magnitude.
  21. perrin6


    From the album: 150mm F8 planetary scope (GSO mirror)

    .23mm (.009 inch) electric guitar wire and 22.5mm edmund optics diag mirror (reflective diameter 20.5mm) -15% diameter obstruction of main mirror. Area obstruction of main mirror by diagonal plus wire is about 2.8%. Wire is attached to bits of old circuit board which is strong & I assume effects little abrasion on the thin wire as otherwise why would it be used to hold delicate circuitry !. The diagonal mirror is quoted as having 1/8th wave accuracy which isn't as good as other makes claims. I initially ordered a quartz mirror from Protostar but this company seems to have problems fulfilling orders as it took my money but provided no evidence of posting and I never received it nor any reimbursement despite polite requests by email and letter.
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