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Cosmic Geoff

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  1. I bought a helical focuser and a set of adapters from them - both were okay for the price. The helical focuser looked the same as one I bought from China except for the size of the adapter on the inner end.
  2. I don't know who owns the copyright of the COAST images (you would have to read the small print to find out), but if you tried imaging yourself with a GoTo scope I expect you would find it to be a very different experience from booking a COAST session.
  3. Be careful what you wish for. The cheaper alt-az GoTo mounts are usually sold bundled with a entry level scope, and are intended for visual use with scopes weighing less than 5 Kg or so. Then there's a big gap to the heavy duty alt-az or alt-az/EQ mounts that you can buy separately, which cost serious amounts of money. Have you a budget? A small ED refractor will cost several hundred pounds. A 102mm Startravel achromat will let you do some basic imaging, and it's cheap, and you can screw on a helical focuser, but it won't be as good or as versatile as an ED scope. You can start wilh the cheap stuff, but if you are serious about deep-space imaging you will eventually want an ED refractor and a heavy-duty equatorial GoTO mount. (and keep your entry level kit as a grab'n go?)
  4. Some hints: Jupiter and Saturn are visible in the SSE sky, fairlly low down, before dawn. Jupiter is too bright to miss, and Saturn is about 1st magnitude and a little eastward of Jupiter. Venus is visible to the naked eye in the north-west at dusk, very low down. If you can identify these planets, the easiest way of observing them is to select the Solar System mode during setup and (assuming you have entered the latitude, longitude, date and time (or let the GPS unit do its thing), just align on the planet you want to observe and it will track it. I am assuming that you have read the instruction manual for the Nexstar system and also aligned the finder. If you can use the Two Star Auto Align, that should be able to find any of the planets for you. Unlike some other GoTo systems, if correctly set, the Nexstar will not let you select planets that are below the horizon. If you are having trouble focusing, aim the telescope at the brightest object (star or planet) that you can find, and turn the focus till the donut shrinks to a point or bright planetary disk.
  5. It is surprising what can be done with an alt-azimuth GoTo mount. With my SLT mount used in an EVA set up with a small telescope and a ASI224MC video camera I have been able to detect Pluto, image various globular and open clusters, various comets, a couple of novae, and the M1 nebula. Typical exposure 5 seconds. This is often much more revealing than trying to see the objects visually, but cannot be compared with long exposure deep sky imaging.
  6. Scopes with short focal ratios, e.g. a f4 or f5 newtonian, will require more exotic eyepieces than one with a long focal ratio like a f10 SCT. I am something of an eyepiece sceptic - if a Plossl seems to do the job, I am not motivated to order an eyepiece costing hundreds of pounds.
  7. FLO quote the payload capacity of the AZ5 as 5KG, so loading 6.3 KG on it is not recommended. IMHO it is better to over-mount a scope rather than under-mount it.
  8. "Making Every Photon Count" has very little to say about planetary imaging. A C8 or C9.25 would do nicely for planetary imaging. While an Edge HD would be very nice, IMHO you don't need this for planetary imaging as the actual fields of view you will be working with are very small (except for the moon). Likewise you may not need a CGEM II - the mount requirements for planetary imaging are not exacting, and I found I could get images with the alt-azimuth SE mount which were just as good as with a CPC fork mount. But the SE is awful to use for imaging while the CPC is very pleasant to use - easy to set up, rock steady, low backlash. If you do not intend to do deep sky long exposure imaging, you can dispense with an equatorial mount and also dispense with the aggro of polar alignment, meridian flips etc. If you do intend to image galaxies. the EDGE HD and CGEM II will be more appropriate. Be warned that by all accounts imaging small galaxies with a SCT is NOT a beginner activity. (and check the price of a EDGE HD focal reducer ). As for cameras and workflow, for planets use an ASI224MC + ZWO ADC, and capture .ser files with Sharpcap and process with Registax6. For DSOs, I don't even try using a SCT.
  9. It is not clear why you want to convert to an equatorial mount. The CPC mount is a good one unless yur requirement is to do some advanced deep sky imaging with long exposures. (The alt-azimuth mount will gove field rotation). So far as I am aware the CPC mounts do not have wifi at all, so you can't blame the mount for wifi disconnections - it must be the accessories. The GPS saves you the bother of re-entering the time and date, and maybe the geographial position (though the latter seems less likely with a heavy CPC1100). I have found that the saving of effort via GPS renders a Starsense less attractive. You don't HAVE to buy the GPS separately - you could choose to dispense with it, but I like having GPS. I have not adopted it on all my mounts because of the cost and the inconvenience of having a dongle.
  10. I use both red dot and optical finders on my small scopes. On a larger scope it helps to have both, as it can be maddening trying to get a stubby SCT and its 9x50 RACI finder aimed acurately enough so that one can see the target in the finder.
  11. I note your comment, but I have not heard of any Mak or SCT suffering damage when used in this way. I frequently did projections with my 127mm Mak without apparent damage (except to a cheap eyepiece with plastic parts .) But a full aperture Baader film filter seems a better option, and that's what I use now.
  12. A telescope can be assumed to be potentially suitable subject to certain warnings: Any plastic parts eg components of eyepieces will melt if subjected to concentrated heat. ( I have a couple of eyepieces with melted retaining rings, and an eyepiece cap with a hole mented through it to prove this) Multi-element eyepieces may be damaged by the heat (maybe the cement holding compound lenses together is vulnerable). I would be wary of using a telescope of greater than 4" or 5" aperture. Finderscopes are a potential danger and should be capped. Projection seems to be deprecated these days in favour of using a full=aperture filter made of special filter sheet (which you won't have time to buy now). This is safer provided that the filter is secure. Or a Herschel wedge (q.v) plus a filter.
  13. With a budget of £300 and an interest in imagery you are going to have to make some serious compromises. £300 may not even buy you a new 8" Dobsonian these days. The Dobsonian design is not intended for imaging. Yes, some people have taken images with Dobs, but some people have also rowed across the Channel. If you are interested in imaging, getting the 'right kit' could easily cost you £1500 or more. Planetary imaging requires quite different kit, but not necessarily any cheaper. I recommend you buy the book "Making Every Photon Count" by Steve Richards, available from forum sponsor FLO, £20 and a few hours reading could save you disappointment and a lot of wasted time and money. Rather than worrying about 'replacing soon' you should note that many amateur astronomers have several scopes and mounts, each suoitable for a different task. I suggest you buy either a basic manual scope to get you into visual astronomy, try hanging a camera on it and see what happens , OR get a basic tracking mount and mount your camera & camera lens directly on it for widefield images.
  14. I don't think it matters what you use so long as it stays in place. I have two cardboard dew shields and one commercial one.
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