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parallaxerr

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About parallaxerr

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    Sub Dwarf

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    Male
  • Location
    Caerleon, UK
  1. Yes, my garden! It's really not astro-friendly and is made up of tiers and what tiers there are aren't flat. The tripod allows me to get the AZ100 level but I fear a dob would rock and roll all over the shop.
  2. Hey Rob, it sounds like your thoughts are very much aligned with my own. It's interesting what you say about the larger scope in the wind, definitely something to consider especially with my less than ideal tripod. I feel a 10" would also require the addition of a Berlebach so the cost is doubled, say £800-£1000 for 10" OTA + BB vs <£300 for just an 8" OTA. I'm probably leaning towards an 8" right now, especially as it will provide a wider FoV without upgrading EP's and is a modest introduction to reflectors. A 200p is cheap enough and could be upgraded at a later date.
  3. Yes, a shame I sold my black version (for CG5) a few years back. Not sure I could stand a white tripod with the AZ100 on top!
  4. Ah, I'm surprised as the tripod looks quite beefy compared to the skytee II. I've seen your images of the AZ100 on the Uni, obviously it's a fair bit chunkier.
  5. Thanks John, good info. I'd be using ES 68° EP's and don't typically obsess over edge of field performance. I must have inadvertently denoted this thread for comment from John's only!?
  6. Thanks John & John. The different perspectives of those pictures really help. @johninderby, is that a Uni or a Planet? Planet I suspect. That's another consideration, I'm currently on a 1.75" steel tripod which is fine for the frac, but I wonder if it would struggle with a 10" on the AZ100? I do use it all but fully collapsed, only extending an inch or so of one or two legs to level, so may be OK.
  7. One thing I have noticed which may sway the decision: When considering what I know to be a good exit pupil for observing from my location, the extra focal length of the 10" does offer a larger image but also starts to really draw in the FoV available with my current EPs......that could get expensive not only in wider field EP's but a coma corrector too. Am I right in saying that using moderate 55°-68° EP's with the 8" would not necessitate the requirement for a coma corrector?
  8. Over recent months I seem to have come around to the idea of a reflector. I've previously resisted having just accepted that I like fracs, but I am guilty of never having owned a newt (I did once have an SCT though). Maybe it's the realisation that large refractors are just too much of a compromise or that having recently collimated a refractor, realising that it's not really a big deal. Ironic that I had to do that when it was collimation that put me off reflectors for so long. Also, there's no arguing with the £/inch of aperture equation! I also now have a capable mount in the form of the AZ100 so I've been looking at OTA sizes and weights whilst trying to keep aperture fever at bay! It would appear that both 8" and 10" newts are being used on similar mounts, such as skytee II's, but the 10" don't half look big! It's so difficult to tell from some images where there's nothing to scale against though, as people often take photos of their kit in isolation. I have used the threads below for comparison... This is purely a DSO venture, though I'm sure both would perform admirably on planets. My winter targets typically being the Veil Nebula, Orion, Andromeda, the Ring nebula, etc. I'm really interested to see how much deeper I can go with a larger scope and to find some new targets, having not ventured beyond 120mm aperture before (apart from the 8" sct but that only really got used on Jupiter at the time). Can anyone comment on whether the additional size and weight of the 10" is worth it over the 8" for the extra light gathering ability? A subjective question I agree, but I'd be interested to hear anyway, e.g. "the 10" doesn't offer much more but is a beast to handle", or "the extra 2" makes a HUGE difference to what you can see". Also, I wonder if the 10" is going to offer any more from my home location with moderate LP, or if it's just going to collect more of the wrong light? Is there a point where this becomes an issue with respect to aperture?
  9. An OVL 27mm extra flat EP. Nicely finished but of kit with a lovely large eye lens.
  10. Hi Don, thanks for confirming . I did realise that and saw it as middle ground between the Tak and RKE. Now, if someone could make a 28mm 68° 1.25" ep, I'd be most grateful
  11. Thanks for the info @Louis D, I've seen your posts like this on CN and they're very helpful! By way of an update, I ordered the OVL 27mm Extra Flat as it seems to strike a nice balance between price and FoV, hopefully it will be comfortable enough to use for extended sessions. I'm hoping it will be of similar performance to that APM 24mm, nice and flat.
  12. I'm just glad I got the Celestron with the collimatable cell! Had it been a SW I guess I'd have been stuck. Will invest in a laser too I think. I did my best to align the focuser with the collimation ep, but there wasn't quite enough adjustment in the 3 screws to get it bang through a full rotation, but it's only a smidge out with the focuser at 180°. Having said that I rarely rotate the focuser any more as I mount the scope lower and the collimation is spot on with the focuser upright. I also checked with the diagonal in and there was no change, so hopefully I've achieved alignment throughout the full optical train.
  13. I took about a bit of astro fettling last weekend, my primary goals were to flock the dew shield of my 120mm f8 achro and to do something about the red diagonal I have which really doesn't match the scope. The diagonal turned out well, a bit of adhesive vinyl and a black paint pen have transformed the exterior whilst the inside got the gray foam side pads replaced with flock. It appears much darker to look through now, hopefully a bit of extra contrast? Whilst removing the dew shield to flock though, I soon became aware of a rattly objective. I know this is no major cause for concern normally, however it sounded too loose for my liking. I fashioned up a tool to loosen the objective lens retaining ring, which oddly was very tight. After standing the tube on the focuser end and doing the tube tap dance, I gently nipped the ring back down to snug up the lenses. All week though I've been concerned that the scope may be out of collimation so did a bit of reading up. It turns out the scope was supplied with a collimation eyepiece which I had kind of disregarded thinking it was a standard accessories pack and the collimation ep was likely meant for a newt. Up the attic I went to recover said ep. Having performed a preliminary inspection with the collimation ep I discovered quite a bit of mis-collimation. Two donuts were visible as expected (reflections of the lens surfaces) however they were only about 50% overlapped, i.e. far from concentric. Fortunately the OMNI XLT 120 had a collimatable lens cell so I took the plunge and got the tools out, only to discover more "looseness" in all but one of the collimation screws. Interesting that previous start testing returned reasonable results, though very soft rings I thought. This meant I had to test very close to focus, perhaps this hid the mis-collimation as racking further in or out just produced colourful blobs. An hour or so of fettling, including focuser alignment and I seem to have a nicely collimated scope now! Initial daytime observations seem to indicate a fair reduction in CA which I always though was a bit high in this scope. It may also go some way to explaining the poor performance on Mars recently. Of course a repeat star test is now required, but the forecast suggests I won't be doing that any time soon! Really looking forward to and hoping for some improvements during the next session! I've added a photo of the view through the collimation ep after adjusting but it's hard to make out the pattern. Suffice to say it was nowhere near round before!
  14. Thanks Ruud, that's how I understand it. One negative I'm picking up on is the effort required to hold the specific position to achieve the effect, which may be less than ideal for longer sessions.
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