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SiriusB

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About SiriusB

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  1. "As an example, when viewing Mars again this weekend I ended up with a 'cloudy' circle all round it." That sounds like high haze, not very aesthetic but not necessarily bad for viewing planets. You can often get steadier seeing with some haze or even an Autumn mist,which sometimes give excellent seeing. For faint fuzzies it's a bit of a kiljoy though.
  2. Sounds right to me. I can see the rings @ about 25x ,I've not been able to see the Cassini at all this Summer in 70-150mm, down to the low altitude, though others may have had more luck/skill. When Saturn was high in the sky 15 or so years ago, Cassini division seen ok in 70 & 80mm scope at around John's suggested magnification. For a bonus point there's seeing the Cassini division & then there's seeing it all the way round the rings, somewhat trickier & most likely needing more aperture. Anyone for Encke's division? Never seen it myself, back when i had a large enough scope to stand a chance Saturn was low in the sky like now. ......One for the future.
  3. Thanks to all for your input. Some very thought provoking replies, I feel i've learned something. .....& to whomever corrected the title.
  4. But, Mike, Would you choose a 3" ED over a 4" Achro ~for planetary, if you were on a tight budget? Just curious, seeing as how you magic great sketches out of modest aperture i'm not going to argue.
  5. I've taken most of my objectives out the cells, probably wouldn't reccommend unless theres a need, which it sounds like there is in this case. If you're too cheap to but the tool a couple of small drill bits or allen keys will often work for removing the retaining ring, not that tight usually (round holes in all the synta fracs i've owned) But the tools are fairly cheap & can be used on EP's too, which always seem locked tighter & more fraught with a potential slip of makeshift tools &..... hey ho, one scratched field lens later....you wished you'd bought the proper tool. My main caution would be in the removal & particularly the replacement of the lens elements. sometimes they stick part way,sometimes they really stick too! When replacing element,s you may want to invert the lens cell & gently push both elements up together with a soft cloth, other way round sometimes you get a nasty [removed word] of glass on glass when one element suddenly 'unsticks' itself. .....Just so you can learn from anothers mistakes.
  6. Yes to stop dew, or in my hazy recollections of 80's Winter observing, i actually had a eyepiece or two frost over Back then the EP case was pretty minimal so effectively end of session! .... & I actually stuck to the EP one night. (rubber eyecups were then not the norm) I guess Stateside it still can happen?
  7. A Good link Dave. .....& for all those who store their FMC Apo's in the shed...... sounds like that's a big no no. ....& for those with less sympathetic other halves, now's the chance to explain why it needs to have pride of place in the dry living room.
  8. Ok, cheers Alan & Dave, SGL on the ball as usual. Only 4 elements but sounds like best to return in this case & only try remedial work when you're already stuck with the EP? It's the potential spreading part i think is of most concern.
  9. Been a bit of high haze here few nights recently, so maybe haze, probably some light pollution also, give it a bit more time to see if you get some better/ worse nights first. I think there's probably better & maybe cheaper filters to use for planet contrast than a UHC, but as i only own 3 filters maybe someone better aquainted might chip in. FWIW, i live in a town, it's not great skies but could be worse. If i lived in a city a big refractor would be my first choice of instrument. Others might disagree.... but it's certainly not a bad choice for urban Astronomy. Ps, when the moons about, i think a look at that might clarify the haze situation .
  10. Anyone suffered from this in an eyepiece? If so, what did you do? .....& For those of you who don't know what i mean, apparently there's a fungus that will grow on lens coatings with the help of moist conditions. Sounds bizzare i know, but true. ( So don't forget the silica gel in your storage box folks.) Only ever seen it on camera lenses, where it can be pretty pretty bad, & i think pretty much junks the lens. Reason i ask is i received EP in post i rather fancied would be a keeper, but has internal fungus,(not that bad but noticeable) Will send back for refund unless anyone thinks it's a practical & longterm proposition to clean it off?? I could be looking a fair while longer for another example, but logically best to return. I'd always assumed lens fungus could jump from lens to lens, so even if i could clean it i'd be worried about an occular fungal pandemic in the future. Any thoughts? Hope I've not given anyone nightmares or sparked an OCD cleaning & checking frenzy. I doubt you'll ever see a problem unless you pack away damp after observing or store in damp conditions. My question is what if anything can/should be done should the problem arise? Thanks.
  11. Not sure i followed all that, TBH, i'm a bit lazy with all this polar aligning. If i had a permanent setup, i'd make the effort,sure~ but unless your doing astrophotography (sorry, i'm showing my age~ "Astro imaging" )...it's overkill?? All i do is set my latitude scale right, plonk the mount down roughly facing north & away i go..... & it does well enough for visual stuff. Not actually used a polar alignment scope in years. Though,I guess if you've got goto, you can't take the lazy option.
  12. Depending on your budget... A 4" Achro or Apo,will be much more satisfying than a 3" apo for planets. IMO I've found an 80mm ED very close to a 4" achro on deep sky, but for planets, i'd pick even the 4" Achro every time,(resolution) So much the better if you can stretch to the 100ED previously mentioned.
  13. Good sketches Lee. Found M71 by accident a couple of nights ago in 150mm. Not The 1st time ever, but certainlynot seen for a while as i had to consult 'Nortons' to determine what i had seen.. A somewhat underated globular? To me it looks more like an open cluster than a globular @ the eyepiece? ~loose. Worth a look anway.
  14. "is there a chance of differences among filterthreads, like e.g. the m49x1 and m49x0,75 thread? Or do i have to use some force?" No don't use force. there's supposed to be a standard ~M48x0.75 for 2" Ep's & M28.5x 0.6 for 1.25" Ep's. But as Merlin stated it's a bit hit & miss. Manufacturing tolerances, some manufacturers using a different thread.....etc Read somewhere that Baader somehow make their filter threads a bit non standard such that they will fit pretty much anything. If it's any consolation, last night a 1.25" filter wouldn't thread onto the EP i was using, has fitted all other Ep's to date including ones from the same manufacturer! This was more down to lack of thread length on filter than a different thread pitch. So yes,it can be a bit frustrating.
  15. You must be a perfectionist if 20 thou makes all the difference?
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