jonathan

Yes, I've heard of Bob's Knobs, I think it must be time for those. I had a thought that perhaps the screws have become stiff over time (I haven't adjusted them for many years), perhaps they've corroded with dew or something like that. I feel that I should remove the secondary module from the corrector plate purely so that I can see what's going on in there. There is a central disc on the outside of the secondary, does that just flip off to reveal a screw? I do recall vaguely unscrewing the inside half of the secondary but I don't rememeber what it looked like behind the mirror. Time for another adventure in telescope maintenance! I see on FLO there are many different Bob's Knobs - does anyone know which would be appropriate for my Celestron 8SE? It has an orange tube but I bought it new only about ten years ago. I'm thinking these will be the ones, I need to remove a screw to confirm that it is metric.

Recently I took the corrector plate off my Celestron 8SE and cleaned it (it was quite badly fogged with dust or something on the inside), this part went well, however it seems that the central part didn't go back quite as it was so now it's rather badly out of collimation (the out of focus bright star shows a black dot far off to one side). I had the scope out tonight attempting to collimate it by twiddling the three screws on the central part however they were extremely stiff, to the point where the heads started to strip, also when I was attempting to turn the screws I noticed the whole central part moving. This worries me greatly - how can I possibly collimate this thing by adjusting the screws if they won't budge, but somehow the whole central part moves about? Anyone who knows what's going on here, please help! I was not able to achieve focus with the scope tonight, a very clear night by the looks of it. I will need to remove the corrector plate and examine the central part, I'm not sure why the screws are so very tight nor how it is able to shift up/down/left/right over the correctly plate.

Oh.. you mean I've been doing it wrong all these years? No joke, I always thought I got better results from my refractor on planets than I do from my 8" SCT because I can use my 3.5mm Pentax, though I do see your point. Certainly a slower scope can't make good use of high mag high quality eyepieces in my experience so one saves money in that respect. But then again the SCT has a narrower field of view, perhaps ideally suited to planetary stuff. Still, I'd quite like to try a big 8" reflector and see the difference for myself.

I would say for planetary observing (visual) you'll ideally have a fast scope so that you can use high power and high quality eyepieces (typically a lot more expensive, could be as much as £300+ per eyepiece for really good ones, but they do make a difference when combined with a good quality fast telescope). F6 is reasonably fast, F5 is faster; faster = more light for any given instance (same as with a camera lens), which basically translates to a brighter image at the eyepiece. You should be able to push an F6 scope to maybe a good quality 4mm or 5mm eyepiece on a clear night, this should enable you to easily see the rings of Saturn, perhaps even the Cassini Division, also the major bands of Jupiter and the Great Red Spot when it's in view. Neptune and Uranus should also be visible in a large telescope however they will be little more than tiny blue discs or dots (because although technically giants they are very very far away). When Mars is in a favourable position you should be able to make out the polar ice caps and also the main darker regions. To give you an example, my 8" SCT is a slow scope at f10, it can't use my 3.5mm eyepiece (everything is just blurry/fuzzy and dim, even a bright planet such as Jupiter), normally it is limited to about 10mm for anything useful at the eyepiece on a typical night, occasionally if the seeing is especially clear I might be able to get something out of my 5mm.

On an unlit polar scope I've shone a red LED torch down the polar scope hole, with the correct angle it should light up the alignment pattern. Tricky to do, but might give you a chance at least.

Had you considered adding 'bluetooth' to your search query? That tech seems to have had a resurgeance in recent times, there might be a USB -> Bluetooth device that you can chain together with a standard USB hub, or something along those lines. Adding Bluetooth to a computer is very easy, although the range and data transfer rate is not as good as with modern wifi.

I was wondering where all the clouds had suddenly come from! 😏

I see some light and dark circles and an out-of-focus crosshair. I think the concept of getting all of the circles aligned down the middle is the same, but I just haven't seen anyone do it with a Cheshire. I'd do it using a bright star that's out of focus but I'm still waiting for a good clear night with no thin cloud.

I had a look down my Cheshire but didn't see a major problem, it maaaaaybe could have been tweaked, but the three screws on the front of my SCT were very tight and turning them slightly didn't seem to make any difference to the position of the circles. I'm wondering if it's different for an 8" SCT, maybe more turn is required? I've tried to find a decent video on using a plain Cheshire with an SCT but they all seem to use a camera, laser collimator, or artificial star.

Just a quick question... Would you collimate with a Cheshire outside on a cloudy day? I don't have many bright walls inside the house and there isn't enough distance for an artificial star (we have small, dimly lit rooms... old house thing). Also, does scope vibration matter? I could plonk my 8" SCT on my CG-4, it's overweight but if the mount isn't tracking then it shouldn't matter.

I skipped the EQ5 and went straight for the NEQ6 Pro, following advice to buy the biggest mount I could afford. Although I didn't want Goto (it's just a different handset) so I have the SynTrek version, tracking only. I'm not sure that the SynTrek version is still available as I generally only see the Goto NEQ6 Pro for sale these days. As for slewing and noise, I've only ever experienced one other Goto mount and that was the one supplied with the Celestron 8SE 8" SCT, that mount made a lot of gear-meshing noise and generally sounded awful, it was kind of overloaded with the 8SE out of the box. Once I switched to the NEQ6 Pro the sound and motion was smooth as anything, a beautiful mewing as it tracks and a pleasant wwweeeeEEEEEeeeuuu as it slews, not silent but definitely not grindy geary. On a windy hillside the NEQ6 Pro is rock-steady, the 2" thick tripod legs will take a lot of weight, but be warned - the mount itself is a very big and heavy lump of metal! Probably one to permanently mount on a pier and/or in an observatory setup if possible. Me, I don't have that so I have to lug it out into the garden each time, it doesn't get a lot of use!

I agree with DaveL59, it definitely looks like there's a loose screw under there. It may be that it slackens itself off due to the simplicity or poor design of the mount / tripod, if that's the case then it can't really be helped, you'll just have to keep a nut driver to hand. If it's easy to remove the telescope from the mount then I'd suggest trying it almost as a hand-held telescope, rest it on an upturned broom or something steady, if you're at all handy with DIY then make a bracket to fix it to a standard photographic tripod (preferably one with a video-style pan and tilt head, or a ball head). Good luck!

You do have to factor in eyepieces - the one or two that you get with a scope are generally mediocre, a good set of eyepieces would be outside of your initial budget but it's something that's well worth saving up for and expanding on to give you a good range of magnifications for different targets and seeing conditions. Consider the BST range, or step up a notch to the Celestron X-Cel or Explore Scientific 82 degrees ranges. One good quality eyepiece could literally transform your viewing. From those ranges I mentioned, if you only buy one eyepiece then I would recommend something in the middle such as 15mm, if you later wish to expand then go for 8mm or 12mm, then maybe 18mm. You'll most likely receive a 10mm and 20 or 25mm with a telescope, the 25mm is good for finding your targets and observing large or bright objects such as the moon (also look at getting a lunar or ND filter to reduce the glare, the cheapest one shown here should be fine). I recommend spending your main budget on the scope first because eyepiece choice depends hugely on what you prefer to look at, just keep in mind that with a new scope in your budget planets will generally still look like small discs or points of light, you're unlikely to be able to split the rings of Saturn or see features on Mars, though bands on Jupiter should be visible under good conditions; I'd instead recommend focusing on wide field observing such as star clusters, double stars, lunar, and for those a 10mm or 15mm eyepiece would be ideal.

I think there was a definite lack of clarity from my position, normally through my refractor the stars are pin sharp points but last night they were just a little bit fuzzy looking. That high, thin cloud was there alright, just not visible in the dark.

Had a crack at this pair tonight with my 102 refractor despite reports of thin high cloud, seeing was middling, could make out three or so bands on Jupiter, Saturn and the rings were clearly visible. Both planets suffered with wobbly atmosphere though due to their relatively low atlitude and my having to view them across the roof tops of the entire village (so plenty of street lights too). A big bank of cloud starting moving up (probably the front of the storm expected for tomorrow) so swung around for a look at some clusters and Andromeda galaxy before I was totally clouded out. Saw a couple of nice shooting stars while just sitting admiring the milky way for a few minutes. Just good to get the scope out, mainly. Missing my astronomy society meetings.

Are leylandii trees considered illegal? A few years growing, job's a good 'un.

In a twist of irony, I have new(ish) neighbours who normally are not active outside after dark and therefore do not have outside lights on (the previous owner seemed to leave a security light on well into the evening). The irony is that a shed has been erected on what was my observing position, and then... one of those annoying solar-powered LED security lights that comes on at the first moth detection. The silver lining is that I have located the on/off pinhole button, just need to add a map pin to my observing equipment!

Maybe we'll get lucky with a big solar flare.

Just observing a beautiful thin and bright thread popping out of the side of the sun, curling and dissipating like the lash of a whip. Is anyone photographing this? Can't really see it on the NASA live photos.

Before buying a dew heater setup I would try just a dew shield, it might be enough for most nights on a 5" Mak. Key is to try not to expose the front glass element to the sky, the dew shield will retain some warm air in front of the glass but keep it pointing towards the zenith for any length of time and Woomph! The warm air is gone, in comes the dew. You can add dew heater tapes or replace the dew shield with a combo one as mentioned earlier in this thread if the dew shield is not enough, just don't expect either or both to eliminate dew every time. On my 8" SCT I place the dew heater tape right behind the front plastic rim, it needs to be as close to the front glass as possible so that it can spread some warmth onto the glass. You do not want it at the bottom end as this will lilkely send warm air currents up the tube and result in turbulence.

Would you be able to point us to a page showing the scope setup that you have please? We should be able to better advise what you can do from there.

If you enjoy Turn Left at Orion then I can also recommend the pair of guides here: http://astrog80.astro.cf.ac.uk/mwm/ The Moore Winter Marathon contains some great targets for telescope, binocular, and naked eye, and in my experience was a great next step from Turn Left at Orion. I don't think these guides are still linked to from the Sky At Night website itself which is a shame as they're fantastic, the form can be used for your own personal records and the PDF guides are still available to download. Print them off to take outside with you (because you don't want to be reading an illuminated screen and destroying your night vision), I laminated mine so that they don't get damp from dew and frost. A word of warning, when laminated and covered in frost they are extremely slippery (not to mention cold to the touch!)

It sounds like the mount is unable to hold the telescope perfectly steady. The mount is the part that sits on top of the tripod (typically), if this is a light-weight piece of equipment then it won't have the capacity to withstand strong winds. Attaching weights only works to hold the tripod down and prevent vibrations that occur through the tripod legs, but from your description it doesn't sound like this is the problem. You shouldn't add weights to the telescope itself, this will likely only make the situation worse. Perhaps you could consider a wind-break? Those things they have at the beach. Or failing that, an upgrade to a heavier mount that can withstand the wind better.

I think everyone's experience is going to be different, the amount of power needed (i.e. how far to turn the knobs) will differ depending on the typical amount of dew at your location, the temperature, the equipment used, and your intended use of the scope. It's probably best to have 'just enough' to prevent the dew from forming, and only personal experience can really help there. I tend to start in the middle and go from there. It's unlikely that you'll be able to feel much heat coming from the tapes, they are designed to only provide a gentle warming effect. If you have 2 channels running and each channel can draw 2A (at maximum power), then I'd say you need to be able to provide 4A to the controller. I have that same controller, I run it from a big leisure battery so I'm never going to run out of amps in a single session, probably not even several (typical session for me is up to four hours). Dew will likely increase as the night goes on, then it will decrease, so it's something you'd probably have to monitor if you intended to do long imaging sessions or whatever.

Dew mainly affects exposed cold surfaces, but especially ones that point directly towards the sky. An 8" dob / newtonian might be fine as the primary is down at the end of a long tube, on a really heavy dew night you might get some on the secondary so a dew shield should sort that, if that happens your eyepieces are likely to be affected too if they are left with the glass exposed to the sky. I have an 8" SCT so know all about dew and where it lands. The main thing is to keep stuff covered when possible (i.e. keep your eyepiece case closed), keep them just above the dew point (so keep eyepieces in a warm pocket with the caps on), in my experience dew normally falls directly downwards but can also cling to surfaces not directly facing the sky. You'll know if there's a dew as it will normally form on the cold outer casing of the scope tube first, or on a car roof. The heat from your skin can cause dew / misting of an eyepiece on a very cold night, I usually find that when that happens it's time to pack up! I run a 4 channel dew heater controller with dew heater tapes on the objective, 9x50 finder (both ends), and eyepiece, and sometimes it's still not enough! I've never had to run a dew heater on my 6" newtonian or 4" refractor though.