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Dunkster

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Posts posted by Dunkster


  1. If you're worried about wide fields of view, a Mak or an SCT is the wrong scope for you :eek::D  however, small and short focal length refractors make a great companion, so your average finder scope will do a nice job of objects like M45, but you could always go bigger...an ST80 for example is cheap and weighs very little and would mount nicely on top of a C11. Or get a nice pair of binoculars...

    The Edge HD features are NOT all about photography, the flatter field and lack of coma make for some beautiful views with whatever eyepieces you choose, and depending on how you store your scope the vents could be useful for cool down. I've not yet found a reason to use the mirror locks though ;)   I use a Pentax XW 40mm with mine with and without the reducer, for about 0.95 (f/10) and 1.35 (f/7) degrees respectively.

    None of these are necessarily cheap options, but quality views never are...you just pay your money and make your choice :D


  2. The 3.25" thread is required because the baffle diameter is greater than 2". At least one manufacturer has announced (but not yet shipped afaik) a 3" eyepiece. The 0.7x reducer for Edge HD (irrelevant here) is 3.25" inch at both ends and doesn't alter backfocus.

    I believe the clear aperture on the 0.63x reducer for normal SCTs has clear aperture less than that permitted by a 2" optical path also, so depending on how steep the light cone is there may be some drop off of illumination there. At f/10, either C11 is capable of up to 0.95 degrees. For planetary and lunar this is moot of course :cool:


  3. The C11 has a 3.25" SCT thread on the rear cell compared to 2" on the smaller models. The C14 and Edge HD models 9.25" and larger also have the 3.25" rear cell. I chucked the reducing ring in the bin the day my C11 was delivered...and bought the Baader Clicklock visual back. Highly recommended if you wish to approach the max FOV of your scope, because the reducing ring is constricted to 38mm.


  4. :embarassed:  sorry Zakalwe, must have had my wine glasses on  :grin:

    I'd still go with the Edge 8 for visual over the standard SCT if you can, stars at the edge are nice and point-like as in the centre, and the vents help a bit with cool down whereas I used to find the standard C8 would take about 2x longer than the C6 to cool down in the UK (which doesn't take long itself if you put it outside while you setup). For me I don't find cool down a problem, I just look at lower magnification targets in the meantime  :evil:

    • Like 1

  5. All of the above :D

    The C8 is a versatile scope, more than 2x the light grasp of your 127 so it'll be more capable of chasing down the fuzzies. It's noticeably larger but only about 1.5kg heavier and well matched to your CG5.

    If you're worried about cool down, look out for a Lymax cat cooler. Alternatively, just start the evening looking at targets that use lower magnification as the tube currents don't affect the view so much.


  6. The Edge HD scopes can make good use of quality eyepieces, so if you have the budget then something like a Televue 12mm or 14mm Delos or 13mm Nagler will last you a very long time, but there are less pricey options that will also do a great job - Pentax XF 12.5mm for example. This will be a good general magnification for globular clusters and planetary, although if you have good seeing where you are you might benefit from a higher magnification (9-10mm or so) for occasional planetary viewing.

    Also, given you've paid the extra for the Edge HD scope, it'd be a good idea to get a nice wide field of view eyepiece... your current 40mm is a good place to start, but you can get other eyepieces of similar focal length that will show you more sky and make good use of that Edge HD corrected image :)  Baader Hyperion Aspheric, Explore Scientific 68, Televue Panoptic, Vixen LVW or a (TMB/TS) Paragon would all do the job nicely, or for a slightly more immersive experience one of the 82 degree designs from Televue / ES / Meade / etc. Choose a focal length carefully depending on how much sky glow you have where you are...if your current 40mm shows a nice black background between the stars then you're lucky ;)

    Personally, I find I get most use out of the 40mm end and the 12-14 (just the two!) and rarely anything in between, but ymmv...


  7. Congrats on your new scope :cool: orange is indeed the proper colour for a C8 :) nowadays the orange ones are the ones for the 8SE and the others are black, optically they're the same but the location of the dovetail is all that is different (well, and the black ones come with an optical finder scope)


  8. Thats a good point Alan. When I first tried a Pentax XW I had the eye cup in the lowest position and had lots of issues with black outs. I then read the Pentax instructions ( :rolleyes2: ) and realised that I needed the eye cup in it's furthest outward position as I was not a glasses wearer - and bingo, no further issues ! :grin:

    If I unscrew the cup, it falls off....is that supposed to happen? Maybe I should read the instructions :D:embarassed:


  9. I've started wearing my glasses with the XW, at least in the shorter FLs, maybe I just need to practice more :eek: strangely I don't find it to be a problem with the 40 :confused: darn Moon was stunting my practising last night, but the forecast is clear again tonight :Envy:

    Much more of a glasses off and get cosy kind of guy :grin: BCO, ES82, Ethos no problem!


  10. Surely focal length is just focal length. Most SCTs have a primary with a focal ratio of F/3 or F/2, it's the secondary mirror that adds most of the focal length.

    Another example would be using a x2 powermate - it doesn't add anything except magnification. More precisely, it doesn't do anything other than increase the focal length of the scope.

    With exceptions (C9.25, C14, new Meade f/8 scopes, undoubtedly more...) SCTs tend to have f/2 primaries and f/5 secondaries. I can visualise those as differently curved mirrors focussing the light on different points. It's the funky lens stuff I'm scratching my head with :eek:

    Going back to the focal reducer, I guess if the scope speed is 6.3 then it is a 6.3 scope but it would be interesting to know if the other unwanted baggage invites itself along for the ride.

    Lucky my shift doesn't start til later, I'm prolly going to waste the morning looking this up...

    All I can imagine, in simplistic terms, is that the focal reducer has some final element that is slightly concave and brings the light to focus sooner/shorter than before?

    Anyhow, f/6.3 is f/6.3 right? Still not a stiff enough test for some of the more hardened optics nuts around here, but good enough for me :D I'm not sure which corrector you have Alan, but the Celestron reducer flattens the field too. It be interesting to experiment with that on the back of your Mak, although I'd expect the baffle tube ultimately restricts your max FOV.


  11. If you need retail therapy faulksy, my feeling is the BCOs are cracking for the price...I "invested" in a 10mm after John's encouraging review and while I've only used it a couple of times (moving, getting engrossed in big wide southern sky things :D ), it seems to give up nothing to the Pentax while looking at Saturn with the C8, at least for most of it's FOV (C8 is on a tracking mount anyway). Also a cracker in my little 'frac with the Baader barlow, both Saturn and the Moon very sharp. Or maybe it's just the better seeing down here :D

    • Like 1

  12. Sounds like the good times continue for orthos :cool:

    Google translate gives a mostly readable version... some interesting points (I post these blindly!), but I appreciate much of this will be par for the course for you more experienced ortho junkies :rolleyes:

    • High performance, low cost eyepiece
    • 4 lenses in 2 groups, 1 + 3 (cemented) Abbe type, no Smyth lens
    • Good results and nearly flat field with their 2x Barlow
    • Good contrast, reduced flaring and low ghosting across the field of view with air surfaces (4) all multi-coated
    • Short eye relief, rubber eyecups to prevent stray light, foldable for eyeglasses(?)
    • Narrow field of view at 44 degrees
    • Parfocal ("shift of focus is negligible")
    • Good for double stars with large differences in intensities
    • and high magnification for planets and especially the Moon
    • 9, 18 and 32mm available August 1st, the rest "coming soon"
    • Like 1

  13. I was looking at the 30mm 100° but its just too much,especially with the cost of a 3" focuser too.i think im definately going to settle for the 20/14/9mm,the 2" focal reducer and the gso coma corrector

    Settle :D keep us posted, sounds like 3 great eyepieces for the money :cool:


  14. Alan, it seems like a long time ago but I don't recall even needing to rebalance as it was setup to handle the 30mm 82 deg model and the C11 is so back-end heavy. Typically when I'm using the "big gun" I seize the opportunity to use my heaviest eyepieces, and I don't think there's one in the bad boy box that's under 700g so it has widened the spread a little :eek: the NEQ6 seems to take it in its stride though :cool:

    All this talk just brings me back to thinking about the upcoming ES100 30mm... :eek::D

    Added: I do recall using the 25 with the C8 too, but the sky glow was so bad it didn't stay in the diagonal long, east Berkshire not being known for its dark skies... I did rebalance that time though, as I remember thinking the EP was 1/4 the weight of the OTA :eek:

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