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Showing results for tags 'newtonian'.
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Hey all, I'm considering the 250PDS. The main use is visual, and the second is EAA (I currently use a zwo183mm). What I'm hesitant about is the primary focus. since It's mostly for visual, I'm wondering on how much back focus it has compared to the standard Skywatcher 10" dobsonians? with the standard dobsonias with the same optics and focuser you already need an extension tube for most eyepieces... Also, there's probably a "bigger" obstruction (bigger shadow on primary)?
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Hi everybody - I'm humbled that some of you are following the thread on the 800mm telescope. I thought it was worth starting a sub-topic specifically related to the mirror making. So as the works on the mount got halted by the lockdown we had some time to virtually meet-up and discuss the optics for this project. The onset was pretty straightforward with an 'if we are doing this we are making the mirror'. And that sorts out the make vs buy, I suppose. As of now, the only two things decided so far are the diameter -at 800mm- and the f/3.3 - of course we can accommodate som
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Due to an unfortunate accident my SN10 primary mirror is broken. While it was an unwieldy beast and pretty much required a complete rebuild when I got it from the previous owner I really loved it. My understanding, thanks to discussions between owners of this OTA, is that the SN10 used a spherical mirror. However Meade's representative did not wish to confirm this "proprietary information" after stating that they could not sell me a replacement. So, I'm stuck with a bit of a quandary: do I roll the dice and attempt to get a spherical mirror constructed? (I doubt that non-parabolic -
Hi, I have changed the focuser on my newtonian but its too short. I realise that I can just add an extension tube to it but I’m not sure if that is the best solution. I also seem to have have a stray light problem (I’m getting a hazy image on a 5mm eyepiece). A third problem is that I find it quite cumbersome that the focuser has to stick out so far (155mm+eyepiece). I wonder if I might solve the stay light problem by extending the main telescope tube instead of the focuser and therefore getting the eyepiece closer to the secondary. And also maintain more precision in the f
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I'm aiming for the best possible field illumination for my Explore Scientific PN208 f/3.9 imaging newtonian. The scope is 5 years old now and while doing maintenance I wanted to do something about the design flaws as well. With the current secondary holder design it's impossible to center the mirror beneath the focuser. My question is: is this really an issue when the entire primary is visible? I read about optimal field illumination when the secondary is centered, but this isn't achievable with this telescope. I attached an image showing the (very bad aligned and alrea
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Hello, I am having a problem with a relatively expensive flat field eyepiece in a combination with a newtonian reflector. I am unable to achieve proper focus with that eyepiece because when I focus it on axis, the edges are blurry. When I focus it at the edge, the center field is out of focus. I don't want to mention the concrete type of this eyepiece because I received it with a spot on the bottom barrel, therefore I cannot be sure whether it has been dropped. This eyepiece has very good reviews on this forum. Optically it looks good and there is no rattle. My question is whether these flat f -
I'm selling my my 70mm secondary mirror I used with my 150mm F4 newtonian for 100$ (final price). Shipping expenses (from Beirut, Lebanon) on me for free provided I use LibanPost for shipping. We can discuss using other shipping methods and maybe splitting the cost. The mirror is brand new, still have the original package and box, bought the telescope a month ago and used only twice. No scratches, not even dust (images attached). Excellent mirror, no issues whatsoever, 94% reflectivity and optimized for the offset of f / 4 Newtons, but it can be used up to f / 5. It's from TS, made in Tai
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Having previously got some reasonable images by mounting a smart phone to the eyepiece. I thought I would try for a more sophisticated set up. So last night I tried to get some pictures of the moon using a Canon Eos D450 connected to a Skywatcher 130p Newtonian via a T2 connection on the eyepiece holder. As the camera has automatic focusing built into the lens I thought I would have to adjust the focuser on the eyepiece holder to manually get a sharp image. Basically the telescope acting as a manually focused lens for the camera. But no joy, I just got a bright light which
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Hi, I recently looked into telescope's & dso's again due to an interesting sight in the night sky . I wanted to get into telescope's etc... but my budget and other things got in the way. This time there's no budget limit (that doesn't mean I'm bill Gates though). My main concern is size since I will carry the telescope with my bare hands (bag). I don't have a local astronomy club or telescope shop around so I don't know if an 8" Newtonian is too bulky/big. Can someone post comparison pictures, if you have an 8" telescope (preferably newtonian, width and length) -
ngc 253 John Herschel in South Africa ( NGC 253, Sculptor Galaxy )
MikeODay posted a blog entry in The Sculptor Galaxy - NGC 253
Sir John Herschel at the Cape of Good Hope Having spent the years 1825 to 1833 cataloguing the double stars, nebulae and clusters of stars visible from Slough, in the south of England, John Herschel, together with his family and telescopes, set sail from Portsmouth on the 13th of November 1833 bound for Cape Town. As detailed below, in an extract from his book, the family enjoyed a pleasant and uneventful voyage and arrived some 5 months later at Table Bay with all family and instruments in good condition. Reading on however, one might very well think that it might not have ended so -
Observations of the Sculptor Galaxy ( NGC 253 ) by William and John Herschel ......... Part 2. Observations of "Caroline's Galaxy" by Sir John Herschel, 1830's Sir John Herschel, the only child of Mary Baldwin and Sir William Herschel, was born in 1792 when his father was in middle age and already famous as one of world's leading astronomers. Having excelled in school, and no doubt inspired by his famous elders, John Herschel decided upon a career as a 'man of science' and set out to pursue a wide range of interests; with one particular focus being a continuation of the
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Observations of the Sculptor Galaxy ( NGC 253 ) by William and John Herschel The very large and bright 'nebula' discovered by Caroline Herschel in 1783, that we now know as the Sculptor Galaxy, was observed a number of times by her 'dear brother' Sir William Herschel and by her 'beloved nephew' Sir John Herschel, Baronet. Some of these observations were recorded and published in the Philosophical Transactions of the Royal Society and, with respect to those by Sir John in South Africa, in the book of Astronomical Observations at the Cape of Good Hope. ......... Part 1. Observat
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The Discovery of the Sculptor Galaxy by Miss Caroline Herschel in 1783 On the 23rd of September 1783, sitting before her telescope in the field behind the house she shared with her brother William in Datchet near Slough in the south of England, Miss Caroline Herschel "swept" the sky searching for new comets and never before seen star clusters and nebulae. On this occasion, way down in the sky, not far above the Southern horizon, Miss Herschel saw and noted down a very bright and large nebula where one had never before been recorded and that was later recognised by her brother, Sir Willi
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I recently tried imaging M7 with my 6" f/4 Newtonian. I had earlier commimated it with a Cheshire and Howie Glatter and was sure of the collimation. However, when I imaged using my DSLR with the coma corrector installed, I get focused stars off centre and not on the optical axis. Anyone experience anything similar before? What could this be? Tilt in the optical train? The focuser was drawn out only about 5mm to reach focus along with a 50mm extension tube. Any suggestion is welcome.
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Hi! I am very new to SGL (just signed up a couple of mins earlier) and to astronomy as well, though I have been facinated with celestial bodies since I can remember. I recently purchased a Celestron Powerseeker 127EQ but now I’m having troubles using it and I can’t seem to see anything through it. I also have a Celestron collimating eyepiece but I still can’t seem to make it work. Anyone here who has experience with the same scope? Would appreciate if we could chat a bit as I would be really interested in your experience and how you ultimately made it work!
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With reluctance I am looking to sell my 200mm aperture f5 Helios Newtonian OTA. (Helios is a brand that became incorporated into Skywatcher - this closely resembles Skywatcher OTAs) The Helios is offered with single speed rack & pinion focuser, tube rings, 22 to 1.25" adaptor, dovetail bar and grab handle for £90 o.n.o. In good condition except that the dovetail bar appears to be discoloured by exposure to sunlight. I have not used the telescope for many months and with a persistent problem in my right arm my enthusiasm for moving heavy kit around has diminished. Buyer to c
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Hello Everyone, I have a GSO 6" f/4 Astrograph, and there's always been this issue with elongated stars on one edge. I've checked collimation and it is perfect, but for the elongation on one corner. Could someone please throw some light on what's happening
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Right now i am imaging with a Star Adventurer and a 300mm telelens on a dslr. I am planning to upgrade to the eq6-r pro and currently i am searching for a telescope. i want to take pictures of nebulae, galaxies and planets. My first idea was to get the Skywatcher 250/1200, then i read that it is too big for the eq6, i was recommended a shorter tube like the orion 10" at f/3.9 or a SCT, due to my budget i can't get higher than the edgeHD 8 unfortunately. what would you recommend? i am also open for different suggestions, thank you :) -
Hi guys, This is the first lights of my ASA 12"N f/3.62 (purchased in 2007) with my Moravian G4-16000 CCD camera using one KAF-16803 chip of 36mm x 36mm (4K x 4K). The adjustments, collimation, ASA OK3-Z pression screws, asked a lot of attention. For a precise collimation, i use the CATSEYE XL & XLKP kit. This is the first 3hrs of exposures taken the last weekend in one night. The second night was too windy unfortunately. Full Resolution image in 4K x 4K here : http://www.poigetdigitalpics.com/Fichiers_Divers/integration_NGC4438_DBE_3HDR_Co
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The Rosette Nebula and Cluster ( NGC 2237 and 2244 ) in the constellation Monoceros edit: updated 30th Dec with improved colour balance and slightly increased brightness ... ...... original: ( please click / tap on image to see larger and sharper ) Still a work-in-progress really... with only 10 x 4min exposures for the main 'lights' before the clouds came over. I will try to add some more data when the moon has gone I am still experimenting with how to get the best out of the D7500. With the very warm nights ( low to mid 20s all night ) the
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The Fighting Dragons of Ara ( NGC 6188 ) ( please click / tap on image to see larger ) The Fighting Dragons of Ara ( NGC 6188 ) Bright Nebula NGC 6188 and open cluster NGC 6193 are embedded 4,300 light years away in the Sagittarius arm of our Milky Way galaxy and can be seen with the naked eye south of Scorpius in the constellation of Ara. With powerful stellar winds and energetic ultra-violet radiation, massive stars sculpt the interstellar gas and dust of the nebula into wonderful shapes and cause the interstellar gas to brightly fluoresce. Closer to the hot
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“The Blue Bunny Nebula” .......... Edit: 27 Jan 2018 - updated again to try to draw more faint nebulosity out of the background; ( NGC 2359 - Thor’s Helmet ) ( please click / tap on image to see larger and without compression artefacts ( and double click on that image if you what to see it as I posted it ! ) ) ......... Edit: 24 Jan 2018 - stars a little brighter and tighter with no change to the rest of the image ( NGC 2359 - Thor’s Helmet ) ( please click / tap on image to see larger and without compression artefacts ( and double click on
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Hi everyone , Have just joined the forum as i am looking to buy my first scope ( well second ). About two years ago i got a National Geographic 76/350 compact scope as a gift. After using it alot i've decided to upgrade as i would like to see more. im still relatively a beginner knowing my way round the sky have bought a few books so hopefully that will help Turn Left At Orion being one. As you can tell by the title i'm looking for something for £200 or less. I'm not looking to do photography with it, i just would like something better than the scope i have at the moment. Easy to use a
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Hello again, After many hours of researching and asking on forums I’ve decided not to go down the imaging road as I’ve come to realise it’s way out of my budget. Now after realising this I’ve narrowed down to three telescopes that I’m considering on getting purely for visual use.. Skywatcher 150p 150pl or the dobsonian 200p. What is the difference between the 150p and the pl? I’m after something that can let me see enough detail on planets that I’ll enjoy and also allows me to get views of deep sky objects. I have been talking to Martin from FLO as well and still can’t decide. I’m hoping -
Help! I have my first Newtonian and can't get it collimated. I've followed along with countless videos and blog posts but never end up with what I'm supposed to have. Is there anyone in the Lisburn/Craigavon area of Northern Ireland that is willing to give me a hand?
