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Hello everyone, I have been looking at a Meade LXD55 Schmidt Newtonian telescope second hand for around £280. In good condition. is this a good deal? And how is this telescope for imaging with a DSLR (I know it’s quite old)? Also, what is the weight of this telescope? Many thanks Josh -
I’m looking to find a dob like mount for a 12” BS Newt. BS 12" (length 110 cm) weight 18 kg. The only requirement is digital circles for push to support a Nexus DSC. Any ideas for a dob based mount? Has anyone used Astrogoods? https://www.astrogoods.com/mounts.singularity.collapsible.shtml
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Hi everyone, I'm new here. Great site! I'm also almost new to this whole thing. I just got my new 12 inch SW dobsonian telescope (upgraded from 6'' SW DOB). I had followed all the steps in setting up the telescope. I hope I've done nothing wrong in setting it up. I've came into a disappointment after trying to view through 25mm because everything came out blurry! Can understand the light is there but blurry. Also did the laser collimation as well but still of no avail. Can someone please help me out? I'm very confused and frustrated. Much appreciated. Thanks in advance for your help! -
Hi, anyone got any experience with the above telescope? I'm looking for an OTA which isn't too large or heavy to use primarily within a bortle 7 zone whilst my AP rig is working away. So it'll be used primarily for visual with the potential for AP afterwards if I choose to make upgrades to the focuser/coma corrector etc. Also does anyone know what I can expect to see visually (difference) from my 60mm refractor? Currently looking though a wide eyepiece at andromeda/orion nebula for example it looks just like a blank void in space, with averted vision you can just about make out the core/nebula. Ideally I'd like an 8" newtonian/SCT but then there's the need for new mount, space to store it etc etc. -
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 well had they but left shortly after ... “... (iii.) Accordingly, having- placed the instrument in question, as well as an equatorially mounted achromatic telescope of five inches aperture, and seven feet focal length, by Tulley, which had served me for the measurement of double stars in England; together with such other astronomical apparatus as I possessed, in a fitting condition for the work, and taken every precaution, by secure packing, to insure their safe arrival in an effective state, at their destination, they were conveyed (principally by water carriage) to London, and there shipped on board the Mount Stewart Elpliinstone, an East India Company's ship, Richardson,Esq. Commander, in which, having taken passage for myself and family for the Cape of Good Hope, we joined company at Portsmouth, and sailing thence on the13th November, 1833, arrived, by the blessing of Providence, safely in Table Bay, on the 15th January, 1834, and landed the next morning, after a pleasant voyage, diversified by few nautical incidents, and without seeing land in the interim. It was most fortunate that, availing himself of a very brief opportunity afforded by a favorable change of wind, our captain put to sea when he did, as we subsequently heard that, immediately after our leaving Portsmouth, and getting out to sea, an awful hurricane had occurred from the S. W. (of which we experienced nothing), followed by a series of south-west gales, which prevented any vessel sailing for six weeks. In effect, the first arrival from England, after our own, was that of the Claudine, on the 4th of April, with letters dated January 1st.(iv.) ...” “Result of Astronomical Observations, Made During the Years 1834, 5, 6, 7, 8, At the Cape of Good Hope ... “ by Sir John Herschel, 1847 John Herschel rented a property and set up the twenty foot reflector near Table Mountain, at a site, that was then, just outside of Cape Town. The Twenty Feet Reflector at Feldhausen, Cape of Good Hope, South Africa, 1834 This telescope was made by Herschel in England and transported, along with his other instruments, by ship to Cape Town and then inland to Feldhausen. The telescope is a Newtonian reflector, built to William Herschel’s design, with a focal length of 20 feet and clear aperture of 18 1/4 inches ( f13 ). The location of the telescope was established by careful survey to be: lat 33d 55’ 56.55”, long 22h 46’ 9.11” W ( or 18.462 deg E ). The site of the great telescope was memorialised by the people of Cape Town by the erection of a granite column that is still there today. ............. Observations of the Sculptor Galaxy Amongst his many thousands of observations made from Cape Town, of nebulae, clusters of stars, double stars, the sun, etc., Sir John Herschel records that he observed V.1 ( CH10 - Caroline’s Nebula - the Sculptor Galaxy ) during two different “sweeps” and gave it the number 2345 in his South African catalogue. Sweeps: 646 - 20th November 1835; 733 - 12th September 1836 At the latitude of Feldhausen, and on these dates, the Sculptor galaxy would have been at an altitude around 80 degrees above the northern horizon when near the meridian ( which was where the telescope was pointed during Herschel’s “sweeps” ). The sight afforded from this location, with the Sculptor Galaxy almost at the zenith, must have been significantly brighter and clearer than the Herschels had thus far been granted from its location way down near the horizon south of Slough. .......... Other Obsevations by John Herschel from Cape Town Also observed by John Herschel in 1835 were the people and animals that inhabit the moon ... The Great Moon Hoax of 1825 - “Lunar Animals and other Objects, Discovered by Sir John Herschel in his Observatory at the Cape of Good Hope ... “ -
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 study of the heavens commenced by his father and aunt, Caroline Herschel. In 1820, with the assistance of his father, John Herschel supervised the construction of a new telescope at Slough in England. As described in the extract below ( from a paper presented to the Royal Society in 1826, titled "Account of some observations made with a 20-feet reflecting telescope ... " ), the telescope had a polished metal mirror with clear aperture of 18 inches, focal length of 20 feet and was modelled on the same design created by his father. It is this telescope, in the 1820’s and early 30’s, following the death of his father and the return of his aunt Caroline to Hanover, that John Herschel used to 'sweep' the night sky and extend the catalogue of nebulae and clusters of stars that was published by his father ( see W. Herschel's Catalogue of One Thousand new Nebulae and Clusters of Stars ). On the 1st of July 1833, having complied sufficient observations, John Herschel presented to the Royal Society an updated list of the positions and descriptions of the Nebulae and Clusters of Stars that he had thus far observed. As noted in the introduction to the paper published in the Philosophical Transactions, he had planned to wait before publishing until he had complied a fully comprehensive general catalogue of objects visible from the south of England. However, due to his expectation of “several more more years additional work” needed to complete the task and his assessment that he now was in a position to address, at least in part, the then current “... want of an extensive list of nebulae arranged in order of right ascension ...”, he elected to present his list, “ ... simply stating the individual results of such observations as I have hitherto made ... “. It was not until October 16, 1863, some thirty years later, that Sir John would deliver to the Royal Society his General Catalogue of Nebulae and Clusters of Stars. As well as introducing many objects that had not previously been recorded, Sir John’s list of 1833 included a re-examination of, and in some cases a small correction to, the positions of many of the deep sky objects observed by his father and noted down by his aunt. One of these re-visited objects was, unsurprisingly, the large and bright nebula discovered by Caroline Herschel in 1783 and recorded in Sir Williams’s catalogue as V.1 / CH 10 ( object number one, of class five ( very large nebulae ) / Caroline Herschel #10 ). In total, John Herschel records around 2500 observations of nebulae and clusters of stars in his 1833 paper; with observation #61 being V.1, the “ Sculptor Galaxy “ . The measured position of V.1is given in RA and the angle from the north celestial pole ( all reduced to epoch 1830.0 ). The description can be interpreted by reference to the legend in the paper. Thus, “ A vL mE vB neb “ becomes “ A very large, much extended, elliptic or elongated, very bright nebula “. He also notes that in addition to this observation, #61, noted down from sweep #306, V.1 was also observed in sweep #292, “but no place was taken”. The figure to which he refers , figure 52, is included towards the back of his paper and is a sketch he made of the Sculptor Galaxy. to be continued ...
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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. Observation of the 'class V nebula', H V.1, by Sir William Herschel, 1783 In 1782, with the fresh patronage of King George III, William Herschel, together with his sister Caroline, undertook the not inconsiderable task of transferring his astronomical equipment from Bath to Datchet ( near Windsor ) in England. Shortly afterwards, in 1983, Sir William began a "sweep of the heavens" with the very large Newtonian telescope of his design and construction. With this mighty telescope's twenty foot focal length and clear aperture of a little over eighteen and half inches, William was able to see fainter objects and smaller detail than any other astronomer of that time. ( source: The Scientific Papers of Sir William Herschel, Vol.1 ) ...... On the 30th of October, 1783, in the course of one of his "sweeps" with the twenty-foot telescope, Sir William Herschel observed Caroline's 'nebula' and noted down ( or perhaps more likely, dictated to Caroline ) a description of what he saw and a reference to its position relative to a 4th magnitude star in the Piscis Austrainus constellation, #18 Pis. Aust. ( with reference to Flamsteed's Catalogue ( or HD 214748 , HIP 111954 as we might call it )). Over the course of the next three years, Sir William would go on to view the Sculptor Galaxy a total of seven more times; as recorded in his paper "Catalogue of One Thousand New Nebulae and Clusters of Stars", presented to the Royal Society on the 27th of April 1786. ( Source ) Sir William's somewhat cryptic notes can be translated by reference to the key provide in his paper and doing so reveals the following: Class: V. ( very large nebula ) Number: 1 Observed ( by WH ): 30 Oct 1784 Reference star: 18 Piscis Austrainus ( Flamsteed's Catalogue; the best reference for the time - we might use epsilon Pis. Aust. or HD 214748 / HIP 111954 ) Sidereal direction rel. to star ( following or leading ): following star Sidereal time rel. to star: 128 min 17 sec Declination direction rel. to star: north of star Declination amount rel. to star: 1deg 39min Observed: 8 times ( up until April 1786, the date of the paper ) Description: - cB: "confidently bright" - mE: "much extended" - sp: "south preceding" - nf: "north following" - mbM: "much brighter middle" - size: 50' x 7 or 8' " CH" denotes that it was discovered by his sister Caroline Herschel The note he refers to expands on details of Caroline's discovery ... ...............................................
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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 William, as the discovery by Caroline Herschel of the nebula he listed in his catalogue as H V.1. ( circ. 1825-33, Sir John Herschel, beloved nephew of Miss Caroline Herschel ) Today we know this 'nebula' to be, not as some thought then, a swirling mass of stars and gases within our own galaxy, but rather, a galaxy not unlike our own but way more distant than the outer reaches of of own Milkyway galaxy. Given various names, Silver Dollar Galaxy, Sliver Coin Galaxy or simply by its number in the New General Catalogue, NGC 253, it is most commonly called the Sculptor Galaxy and we owe its discovery to the first female professional astronomer. Caroline Herschel ( 1750 - 1848 ) ... ( link ) ( 1782 - 1783 ) ... ... ... H V.1 Observed ( by WH ): 30 Oct 1784 128 minutes, 17 seconds following and 1 degree, 39 minutes north of referenced star Description: - cB: "confidently bright" - mE: "much extended: - sp: "south preceding" - nf: "north following" -mbF: "much brighter middle" - size: 50' x 7 or 8' from: ( link ) ............................... The location reference to H V.1 ( NGC 253 ) in William Hershel's catalogue is in relation to a star found in Flamsteed's Catalogue, 18 Pis. Aust., which is #18 in Piscis Austrainus or Epsilon PsA, the 4th magnitude star HD214748 ( HIP111954 ) ( source ) ( Plate from "Atlas Coelestis" by John Flamsteed, 1646-1719 ) ------------------------------------- William Herschel found favour with the King and was granted a position as Royal Astronomer to George III in 1782. Shortly after, William and Caroline moved from Bath to Datchet ( near Windsor ) and took up residency in a rented house which, whilst somewhat delapadated and damp, had ample accommodation and fields for William to construct and deploy the large telescopes he wished to build. It was in these grounds that Caroline set up her "Sweeper" to look for comets and doing so also discovered a number of 'nebulae' including ( in 1783 ) what was later to become known as the Sculptor Galaxy. ( The Herschel house at Datchet near Windsor ) ( The Lawn, Horton Road, Slough ( Datchet ) - Google Maps ) ............. Caroline Herschel's "Sweeper" was a 27" focal length Newtonian telescope that was supported in a kind of altitude-azimuth mount consisting of a rotating table and a small gantry and pulley system that was used to effect altitude adjustments by sliding the tube up and down against a board used to provide stability. There has been some conjecture as to the exact details of the construction, however the image below, even if perhaps not the actual instrument, gives an indication of the overal design philosophy. Late in her life Caroline Herschel recorded details of her telescope in a booklet titled "My little Newtonian sweeper": In her memoir, Caroline Herschel describes the performance of her observations as the conducting of "horizontal sweeps"; from which one might assume the task consisted of setting the altitude in accordance with the plan for the night's observing and then slowing rotating the top of the table in azimuth as one observed and noted down the objects that passed across the view in the eyepiece. However, with the arrival of this new "telescopic sweeper" in the middle of 1783, Caroline Herschel added the new method of sweeping in the vertical, as noted below in an extract from her observing book ( source for both extracts: "Caroline Herschel as observer", Michael Hoskin, Journal for the History of Astronomy, 2005 ) .... The achievement of her discovery of the 'nebula' in the Sculptor constellation was remarkable in so many ways; not the least of which being the low path in the sky that the Sculptor galaxy follows when observed from Datchet in southern England - which on the night of her observation would not have exceeded 12 degrees or so above the horizon. Today, 234 years later, and blessed with 21st century luxuries and conveniences, I write on my IPAD and flip over to my planetarium application, SkySafari, and model the sky as it was seen by Caroline Herschel from near her house on the 23rd of September, 1783 ... ( SkySafari by Simulation Curriculum )
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The Jewel Box ( NGC 4755 ) is an open cluster of mostly hot young blue-white stars that appears to the unaided eye as a bright 4th magnitude star close to the Southern Cross. Only visible from southern latitudes, the Jewel Box was first recorded by Nicolas Louis de Lacaille during his visit to South Africa in 1751 and was later described by Sir John Herschel as "a casket of variously coloured precious stones" - hence the name "Jewel Box". The Jewel Box open star cluster ( ngc 4755 ) in Curx ( please click / tap on image to see larger and sharper ) Please see here for image details.
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Also known as the Theta Carinae Cluster, The Southen Pleiades is a very bright open cluster in the Carina constellation. It was discovered by Abbe Lacaille during his visit to South Africa in 1752. Containing around 60 stars, IC 2602 shines with an overall magnitude of 1.9 and its brightest member is Theta Carinae with a visual magnitude of 2.7. This cluster of young blue stars is relatively close to us at "only" 479 light years. 5 May 2018 The Southern Pleiades open star cluster ( IC 2602 ) in Carina ( please click / tap on image to see larger and sharper ) Image details can be found here.
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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 field eyepieces are usable with newtonians as these telescopes doesn't generally suffer from the field curvature. Many thanks for help. -
Here is the telescope project I am currently working on. The big picture is to have a 900mm Newtonian on a Bailey split ring equatorial mount. The rig will be used in a backyard mini remote observatory and also be portable. I may put it on a small trailer I have, I'll have see how "portable" it is first. I might be able to just put it in the back of my SUV if it's not too heavy, then just mount light duty wheels on it for carting it around the yard. Most of the time it will reside in the backyard, under cover of a mini remote observatory, well that would be nice anyways. At the very least it will have a small enclosure to protected from the elements and to keep it ready for imaging. I won't go into details on how I am going to control everything, because I don't know yet. I do have a generally layout for the scope cobbled together. It is a Serrurier truss ~900mm f/6 150mm. I'm going to try to keep the trusses symmetrical front to back, but the COG may change depending on how things weigh up. When my mirror blank gets here I will be able to start building my mirror cell. I've already got that part more or less figured out. I'll fine tune the drawing based off of actual measurements, right now I've just drawn a 6" nominal blank. It is a moving mirror frame with roller edge support like what Lockwood and JPastro use on their big mirrors. I've just made mine under-hung to line the COG of the mirror over the collimation points. I am going to grind the primary and fashion a secondary elliptical mirror from Zerodur flats. It has a 1.2" /1.92° diagonal 100% illuminated area which will cover a cropped DSLR sensor using a 2" secondary. The central obstruction is 33%. I'm flip-fopping on the focuser right now. Ideally it's going to be stepper driven kind of flat Crayford dovetail sled thing. The nice thing about this concept is I don't need a T-ring or anything, perhaps just a field stop baffle, the camera would be mounted by the 1/4"-20 connection on the camera. This plan might be temporarily diverted in favour of a simple manual helix focuser. My DSLR is a Sony, so I can't go crazy just yet until I know how to get the Sony working with autofocus, remote imaging etc, if it's even possible. It's looking like I'll have to get a new camera down the road at some point and build the custom sled then. This means I will probably make the front half of the OTA removable to accommodate an upgrade, which is less then ideal but perhaps the pragmatic thing to do. The helix and T-ring would make attaching a collimation cap possible, I wasn't sure how I was going to collimate the DSLR on a sled using live view, though I'm think something could be sorted out when I go that route. The focal ratio was chosen as a balance of field of view, tracking abilities, ease of mirror fabrication and dependencies on correcting optics. I was originally considering f/4 or f/5, but this requires a higher degree of skill and effort to make the mirror and makes the mirror tied to a comma corrector. I would prefer to have all reflecting optics only. I don't want my fancy pants mirror to be dependant on a refracting lens, that would be blasphemy. lol. I'll save the coma corrector purchase for a big fast visual scope one day, my mirror is small and not visual so why battle coma. Also with f/6 I'm hoping is going to have a decent field curvature plane vs a faster mirror for my DSLR sensor. It will be made from 17.5mm/~3/4" Baltic Birch plywood. The OTA below is ~900mm/36" long and 305mm/12" in diameter. Baffling will be added and fine tuned later on. I'm really only concerned with 100% FIF but in reality it's very close to the 75% illuminated diameter in this configuration, so will just go the the 75% baffle diameters that Newt for the web gives me. It is a fun project.
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Hi All, I purchased a GSO 6" f/4 Newtonian "Astrograph" late last year and eventually found that stars on one corner were egg shaped while taking images. I narrowed it down to improper centering of secondary mirror from the factory and resulting tilt. Long story short, after numerous iterations, I used the Advanced Newtonian collimation technique by Astro Shed guy and ended up with the below pic of the optics. Does it look ok or do I need to do more? I will be checking with a Howie this weekend too.
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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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Hi! I just remembered I had made a short gif of Neptune this summer over two nights. My fast reflector has a huge field of view, so you can't really make out any detail on the planet's surface. But you can still definitely make it out, and see that Neptune did indeed wander over the time of a few nights - a planet indeed! Enjoy, and let me know what you think!
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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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I am thinking on grinding my own lightweight mirror (first f4 16", later f4 24"). The lightest and cheapest option is to get a thin blank and slump it in a decent kiln. Anyone has longer term experiene with slumped mirrors? Overall doesn't seem to be more work than a normal (not pregenerated) blank. Do I have to grind the backside as in case of normal flat back mirrors to avoid astigmatism? How do people support a convex back while grinding? Does it make sense to grind a hole in the middle for additional support? I am remotely considering a convertible Newtonian/Cassegrain system anyway...
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Purchased the Orion Astroview 6 three years ago. Found out later that I could not attach my Canon EOS XTi and obtain focus. Everything I saw online required sawing and drilling the OTA. That makes the scope a single purpose telescope. After reviewing the primary mirror holder I created a holder that moved the mirror 25 mm. This way I can keep the scope ready for visual observing and sell later if I desire. If you're interested in saving a few dollars in this hobby check out the link below. How I Moved Prime Focus: Link to the detail. Photo from this telescope
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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 :) -
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?
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Hi everyone, I'm looking to buy an 8" newt for astrophotography with my Canon 6D full frame. I'm really only going to be using it for imaging so visual problems (such as back focus) aren't too much of a concern for me. I'm aware that probably whatever scope I get won't cover a full frame sensor without vignetting, but does anyone have an opinion on which would be the best? I have a CGEM mount and Baader MPCC mkIII. The ones I've been looking at right now are: 1.Orion 8" f/3.9 Newtonian Astrograph 2.Astro-Tech f/4 Imaging Newtonian I've also heard of the Sky-Watcher Quattro series and Meade LX70 series, I just haven't heard as much about either of those. Also, optics are my #1 concern. Things like weight or minor mechanical shortcomings that I could potentially fix are not as great factors. Thanks for your input! Patrick -
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 focuser by not extending it. As it stands the focuser would have to come out 265mm from the centre of the secondary mirror in order to focus. The secondary is 50mm wide. From primary to secondary is 950mm approx.. The primary is 200mm Thanks for reading. Any advice will be much appreciated.
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Hello, Is anyone here using the TS Photon 6" F4 newtonian? I'm about to purchase it but I have some doubts and questions: 1- Does it hold collimation well, at least in a single session? 2- Is it impossible to balance in DEC due to its small dovetail or is it possible but harder? 3- Is the focuser rigid enough or does it introduce tilt? 4- Will collimating it be a nightmare? 5- I'm really picky when it comes to coma, should I expect some coma on edges even while using the Skywatcher Aplanatic F4 CC? 6- All in all, do you advice me to buy it or have some other option in the same price range. Cheers! Anthony
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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 seemed to fill the camera view finder. I tried various settings on the camera, adjusting ISO and aperture etc, I also had some extention rings for the camera lens so tired fitting those to extend the focal length but no better. I sure there are many palms being slapped against foreheads reading this but as you can tell I have no idea, although I do have some of the gear. Any pointers and/or advise would be gratefully received.
