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John

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John last won the day on May 13

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About John

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  1. Saxon is usually a re-branding of Skywatcher / Synta made products. In this case I think the Saxon Cielo HD eyepieces are a re-branding of the Celestron X-Cel LX eyepieces so look for comments on the performance of the Celestron versions (which are quite popular on here) to get an idea of performance. Celestron is another brand owned by Synta these days. Having tried a few of the X-Cel XL's I think they are decent eyepieces but quite not as good performers as the Delos or, with the exception of the wider field of view, the Vixen SLV's.
  2. A small slice of the L-chondrite meteorite Aba Panu that fell in Nigeria on April 19th 2018. Collected within days of the fall so not subjected to 100s or 1000s of years of the Earth's weather. Fresh from the birth of the solar system and newly arrived on this planet !. The link below is to the Meteoritical Bulletin entry for this meteorite: https://www.lpi.usra.edu/meteor/metbull.php?code=67799
  3. My Orion Optics 12 inc F/5.3 dob weighs in total about the same as a Meade / GSO / Skywatcher / Bresser 10 inch dob. My base is 18mm marine plywood which is stronger but weighs less than the MDF board that the mass produced ones use. Orion Optics tubes are aluminum which again saves some weight.
  4. You could practice on a quasar of around the same brightness ?:
  5. There is always a "law of diminishing returns" when it comes to optical equipment. The trick is to decide where on the price v performance curve you are comfortable with being and to make the most of that I think. Note: the above sounds so logical and rational. I wish that I could adhere to it myself each time something tempting comes along
  6. I agree with the above views on optical quality of the mass produced dobsonians. Pretty good for the price charged and certainly enough to deliever the potential performance that the apertures have to offer. In the UK we have Orion Optics who offer higher quality mirror options in their scopes but the price (when purchased new) is substantially higher than the far eastern scopes such as Skywatcher, Meade, Bresser GSO etc. On the used market an Orion Optics scope with their better quality optics can make an atttractive proposition though. I guess if you want the best of all something like an Obsession dobsonian with a primary mirror from one of the top opticians such as Carl Zambuto might be up there ?
  7. I've owned a few of the Chinese F/8 6 inch achromats over the years. They show quite enough CA for my eye so I've avoided the F/5's and the Petzval versions. The other issue with these Chinese achromats is spherical aberration (SA), displaying either under or over correction. This has the effect of limiting the sharpness and contrast of the image at higher powers and resulted in all the scopes of this type that I've owned (4 Syntas and a Meade at last count) lacking in image quality at much over 200x. For me, SA is just as bad if not worse than CA in limiting scope performance. I managed to improve the performance of these F/8 achros substantially by using a Chromacor CA and SA corrector. These somewhat exotic devices are not filters but optical correctors and they do a remarkable job in bringing the wavelengths of light to focus at much closer to the same point - similar to the performance that a decent ED doublet achieves in fact. Correctly matched to the objective the Chromacor will also correct SA and when fitted correctly these devices revealed to me the extent to which these aberations impact image quality. Eventually I decided to move to using ED doublets and thats where I'm at now. If I go for another 6 inch refractor it would be an ED doublet. For what it's worth I've read many reliable reports that the 152mm F/5.9 achromats such as the Altair Starwave 152 (link below) deliver CA correction as good as the stondard Chinese F/8 achros and have better figured objectives as well so negligable SA: https://www.altairastro.com/starwave-152mm-f5.9-achromat-refractor-telescope-with-3-crayford-focuser.html
  8. I've seen magnitude 14.7 point sources with my 12 inch dob so Pluto should in theory be possible but I have not yet tried for it. It think to convince myself I would have to make observations over successive nights and sketch the visible star field including any faint "suspects" and look for the one that shows movement against the starry background over several nights. When objects are lower in the sky, atmospheric extinction makes then fainter to see than their reported magnitude. With Pluto being so low here that might push it below the threshold for me but down under your circumstances might be more favourable Geoff
  9. Lovely report Neil - very nicely related The group of galaxies here is known as Hickson 68 and is a worthwhile target under a dark sky even when there is no supernova to draw attention to it IMHO. Tonight here the thin cloud precluded galaxy / SN spotting so I had to stick to some of the brighter binary stars.
  10. My outreach eyepiece set is: - 7.2-21.5mm zoom eyepiece - Baader 2.25x barlow lens - Orion 27mm Edge-On eyepiece This set covers a lot of options, cost relatively little, is easy to view through and all three items can fit in my coat pockets easily In fact I seem to be using these quite often when observing on my own at home as well.
  11. Mine as well My old Tasco 60mm refractor first showed me this golden yellow pair. I was very excited !
  12. I've used the ES 1.25 inch 2x Focal Extender and found it to be an excellent performer as well as very nicely made. very close indeed to the Tele Vue Powermate in optical quality I thought. Edit: I can see that I posted in the above thread to similar effect - at least I'm being consistent !
  13. I was thinking of parting with my Delos 14 because I haven't used it much but after last night I have reminded myself what a super eyepiece it is in the 12 inch dob. The globular clusters M13 and M92 were wonderfully presented and resolved with it together with nice surrounding starfields against a very black sky background
  14. I think Mark was observing in his garden but the galaxy was almost overhead and he does know his galaxies, does Mark
  15. Great report Ed and congrats on getting Zeta Herc ! I've had a mild obsession with that binary star for sometime now. I first managed the split with with a 150mm F/8 refractor, then eventually with my ED120 and now I've managed it with the Tak FC-100. It's a challenging pair alright with it's closeness and uneven brightness and a stern test of observer, conditions and equipment. I agree that it's when you are observing targets that push towards the limits that quality optics show their worth.
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