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Cosmic Geoff

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Everything posted by Cosmic Geoff

  1. Cone error is an error pertaining to German equatorial mounts. If you are not using a German equatorial, this suggests you have a problem with the software. In any case I do not see what this has to do with the GPS dongle.
  2. Your options for a Alt-Az GoTo fall into two groups, those barely adequate for your 4.1Kg scope (and don't forget the added weight of finder and eyepiece) and those like the Az-EQ5 with a much greater capacity and a much higher price tag. One of our astro club menbers had the ST120 on an Ioptron alt-az GoTo, IIRC.
  3. The plug connection between cable and mount is a common source of trouble. Touching it can cause the connection to momentarily break, causing the GoTo setting to fail. You can fettle the split center pin or use a cable tie etc to stabilise the cable. There is no 'best battery' - any power source that supplies a clean 12 to 14 volts and adequate current will suffice.
  4. A decent field of view for what? Potential deep-space imaging targets vary hugely in size, from the Orion ring (very large) to planetary nebulae (often very small). Any given rig will only cover a limited range of targets to advantage. A telescope like the one you cite will cover a range of targets but you may struggle with the very large, or the very small. With the Seestar S50, for instance, some nebulae fit nicely, but some are too big for it, and all but the nearest and brightest galaxies come out looking rather small. I would suggest that both your quoted mounts are totally inadequate for the intended purpose. I suggest you look at the EQ-5 Synscan as a minimum. A lot of imagers who presumably know what they are doing use an Eq-6. For long exposure runs you would want an equatorial mount to avoid field rotation.
  5. The Powerseeker 127 does not have a good reputation, because of its 'Bird-Jones' optical design, which compromises optical performance in favour of compactness. If you can't source a cheap used tripod & mount for it, it might be better to cut your losses and buy something else. Astronomy is not a cheap hobby. 🙁
  6. I can't say I have managed to capture the Encke division. It's extremely narrow (about 325 miles) compared with the overall size of the ring system. (The diameter of Saturn is about 74,000 miles, and the diameter of the ring system about 170,000 miles.) The Edge versions are allegedly finished to a higher standard.
  7. Depends on how these scopes of yours are mounted. If the C11 is not permanently mounted on the EQ6, I foresee a certain reluctance to heave these heavy items outdoors, erect and align them for a session interrupted by cloud etc. If it is permanently available, I do not see any pressing need for yet another scope. Have you seen and handled a C11? You might conclude that mounting it up without assistance would be no fun. I have retained my C8 SE + Starsense as a lighter weight and quick to deploy alternative to my CPC800 which is much heavier and has to be assembled before use. BTW I imaged E & F in the Trapezium with the CPC800 so the C11 should do it too.
  8. I have a slightly different take on this as I have a EQ-5 Synscan mount permanently set up on a pillar. The setting circles: Purely ornamental. Total waste of time. ignore them. Mechanical polar align: get Polaris near the middle of the field of view in the polarscope. Scope horizontal. (I can't get my head around the instructions for aiming more accurately). Check that the finder (a red dot) is pointing close to Polaris. Electronic alignment (or re-align): Start with the scope in the start (or park) position with scope above mount pointing to pole, and counterweight down, to North. Follow the handset instructions for 2-star align, it should slew to near the first alignment star, centre with red dot finder, then scope. Repeat for second star. When done, if you have recent software, you should get a prompt to fine tune the mechanical adjustment (probably not easy to follow). At end of session, command the mount to Park, and remove the power. At beginning of next session, command the mount to start from Park position. No more aligning! If perfectly set up, the GoTo performance of the mount should be quite good, but in practice I found the all-sky GoTo performance of mine to be awful, and I rely on Plate-Solve and resync in Sharpcap to find anything. You query what is a red-dot finder? It projects a red dot (or circle) against the night sky. If you don't have a finder (either red-dot or optical) you will find aligning the mount to be extremely difficult.
  9. I have a 8-24 mm BST Starguider zoom eyepiece, which was very inexpensive. It looks the same as the Celestron zoom, and in fact a number of the more budget 8-24 zoom eyepiece brands look (or looked) the same, as though they all came off the same production line. The Starguider zoom is OK optically, but the action is so stiff that I can't zoom it in situ, but have to take it out of the holder and grip it firmly in both hands to adjust the zoom. You get what you pay for, I guess.
  10. As a Seestar owner/user, I can point out that while having an altazimuth mount should cause field rotation to be apparent on longer exposures, one finds that on some exposures field exposure is indeed apparent, shown by wedge effects at the edges of the frame, but on other exposures the field rotation is not apparent. I don't know why, but I suspect that the Seestar software tries to disguise it for the smartphone images, and the degree of success may depend on sky transparency remaining the same throughout the exposure.
  11. Celestron C9.25 XLT Reviewed: Highly Recommended! (telescopicwatch.com)
  12. Of course it does. A dewshield should be standard equipment on a SCT. Refractors have dewshields.
  13. I would also be nervous about buying a £1000 scope on ebay. The Stargazers Lounge or Astrobuysell would be safer. Or an established dealer in used astro gear.
  14. Certainly not cheap if you buy new. But a used SCT would be half the price of a new one, and if you don't like it you can move it on without much loss. I have bought two used SCTs and (after collimation) I have no complaints about their optical performance.
  15. My personal relevant experience was that visual observing of planets was a somewhat disappointing activity. I could reveal much more detail by imaging. For instance, with my 127mm Mak I'm not sure if I ever saw the Great Red Spot visually, but I managed to image the GRS easily. Re. SCT vs Newtonian, my C8 SE performed rather better on double stars than my 8" Newtonian (now sold). I also found that SCT performance was significantly affected by an almost un-noticeable error of collimation, only revealed by a side-by-side test with two 8" SCTs.
  16. I think that any kind of scope could be used as a planetary scope, with the exception of short-focus achromatic refractors. Aperture is desirable, the more the better, the constraints being budget, portability, and the greater sensitivity of big scopes to poor seeing. If you want to image, the SCT scores on account of having a wide focal range, meaning you can attach a camera, diagonal, filter wheel, or flip mirror or some combination of these, without any danger of being unable to get focus. With a Newtonian you may find that you can't even attach a camera without having to modify the scope, and anything like a flip mirror will be a no-no. Then there is the question of the mount. A big scope, if you require GoTo, requires a heavy expensive mount and , and in large sizes, maybe even a permanent observatory. Here again the SCT scores in the larger sizes as it is shorter and lighter than an equivalent Newtonian and the mount requirement scales accordingly. If you are not going to image, a Dobsonian will offer a big cost saving over a SCT or German equatorial mounted Newtonian
  17. Also known as a GoTo mount. 🙂 Or a digital setting circle upgrade for the XT-8.
  18. Had a go with the Seestar on a cool and slightly hazy night (3 March). M109 turned out well this time, likewise M108. I wanted to find comet Kushida 144P, but unlike 12P/Pons-Brooks it is not in the Tonight's best list. I found a Search box at the top of the screen and found that if you tap there twice a keyboard appears. I entered Ku- found the comet and spent a few minutes trying to image comet 147P/Kushida-Muramatsu (note the subtle error). It appears that the searchable database of comets and other objects is very large. 147P/K exists but is unobservable. Tried again for 144P . The starfield kept sliding downwards on the screen, and when it stopped doing that no faint fuzzy showed on screen after 2 minutes. I gave up and tried for comet 62P/Tsushinchan. Better luck here - quickly detected a fuzzy and got an image of it (28 mins). This comet is reportedly about as bright as 144P. That search box is useful, but we could really do with a proper Seestar user manual!
  19. I got a nice image of Comet 12P/Pons-Brooks on 2 March. Also imaged NGC2903, M74, and IC447 with less impressive results. Imaging M109 was a total fail. Not sure why, as a platesolve of the saved image indicates the Seestar was pointing at the right RA & Dec.
  20. I don't think the OP is going to return and enlighten us. If you look on the Meade website, it pictures the 'Starlock' as a sizeable refractor/guidescope, comparable in length to the main OTA. Astonishingly, the setup includes a third optical assembly, for detecting widefields. I wonder what it all does. If I had a country property, a rollon/rolloff observatory and a wad of money, I'd be tempted to get one.
  21. One scope to do everything never works well. That is why I have four. I have found that the inexpensive 102mm f5 Startravel works well for EAA. With the money saved you could find a 6" visual scope that doesn't weigh 9 KG or cost £600.
  22. I have several mounts where the power is fed in via a 5.5/2.1 connector, and each of them have proved prone to intermittent connections if the plug is touched or disturbed, which loses the GoTo alignment. As I wrote above, rubbish. Fettling the split center pin helps, but only temporarily. Providing a cable restraint next to the plug also helps.
  23. Apparently the LX850 was a mount, which was bundled with a range of Meade SCTs. Meade 14" f/8 LX850 ACF Telescope with StarLock and Tripod Apparently the Starlock is a refractor guide telescope attached to the main one. Visible in photos? You would be advised to get an expert valuation. If you can figure out what exactly you have got, using the Meade site, just divide the price of a new one by 2 for an approximate valuation.
  24. I doubt that you can buy a full aperture solar filter for this scope, so as Naughty Neal says, you can make one. Alternatively, you can project the sun's image onto a card. Just make sure that the eyepiece used contains no plastic parts that could overheat and melt. What do you hope to image? If you have the standard manual alt-azimuth mount, this outfit is not well suited to imaging anything. If you are on a budget, your best move would be to try through the eyepiece shots with a smartphone, starting with the Moon.
  25. I can't give a complete answer, but would point out that the 'cigarette lighter' and the 5.5/2.1 connectors are both rubbish. Industrial connectors would perform better, but would be troublesome to source and fit. The AVX mount requires 3.5 amps? - that will be the current required for slewing at maximum speed. The current required for tracking will be far less. A current rating for a cable is a guideline rather than a hard limit. Common sense is required. A cable that is adequate when completely unrolled might overheat when coiled on a drum. A very long 18 AWG cable might give an excessive voltage drop, while an under-rated cable two metres long might not. Specifiying a heavier grade cable (thicker, higher current rating) will cause no problems, except that it will cost more, weigh more, and be more difficult to handle.
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