Charic

First Light Optics have them at £275. In-store Jessops, I noticed the reflector scope was facing the floor, not the sky? who sets them up, what is their knowledge? better support and help from Flo!.

lol........and I though I was North? 6.5 Hours from you, and still another 3.5 Hours drive North if you wanted to visit Dunnet head, the most Northerly point on the UK mainland ? Aside though, the Jet-stream this far North is really playing havoc with the weather this Year, making observations very difficult, and the seasonal lighter skies don't help either! But on a Moonless dark night, its crazy up here, up in the night sky, things moving all over the place, and many more to see with binoculars, as most are too faint for naked eyes, well mine anyway! Easy to track them if looking through the telescope or binoculars, but then a naked eye peek, and their gone! but even the bright ones fade out if you watch them long enough.

Having owned some Starguiders for some time now, I have discovered that they have one serious issue ? I've tried cleaning them, cooling them, warming them, even swearing at them, almost to the point of sending them back for a full refund ? Yes their great value and very comfortable in use, yet they still can't see through these persistant stinking pesky clouds, thats the only issue I have with the BSTs. ;-) Am I really asking too much lol.

......... the further of axis you go, the worse things will appear or may appear to some folk? as a result of the telescope's faster focal ratio, unless corrected in some way! The BST's are rated down to f/5. You can always send the eyepiece back if its no good for your needs.

I`d wait until you know how much is available first? Sort out any outstanding bills and deficits, then get comfortable with your new budget. The hobby can always come at a later date. I once waited for some winnings on the pools back in 1984? How shocked was I with the payment, considering the rumour mill suggested I was into a small fortune. not the case! I think a minimum daily prize Postcode win in the UK is £1000, which is not much in the grand scheme of things if your wanting to venture into Astrophotography? and according to the rules, every Sunday, every ticket in 15,000 postcodes wins £10. Lets hope your lucky and win big!

........that seems to be a problem? I have only ever found one, my 25mm? There will always be some negative reports around, no matter what the eyepiece brand? and from some of those reports I've read, I expected more BSTs to be available for me, at the lower second hand price spectrum ( I like something for nothing?) however those that own them, love them, those that don't, just assume? and I really haven't seen many for sale since my 1st BST purchase. I wouldn't advise them for scopes faster than f/5 if your worried about coma off axis in a Newtonian telescope, but they work very well for my f/6 Pu-To scope?

Timmyc300.......BST Starguiders. There was a name change from BST Explorer, but they are physically the same eyepiece. Unless the site states specifically otherwise, you should receive the BST Starguider ED branded eyepiece. Sirius Starwatcher.......The latest 3.2mm is Starguider branded. I'd hope that one would become available straight after Christmas, used, as the magnification will be very high for the 200P., but that never happened? but at 375x power, the 3.2mm works fine on the Moon, but you'll need to track fast and smooth to keep up on a Dobsonian, but the quick test I had was good for my use on the Moon. To be honest, this last few Months, I've often wondered why I ever bought a telescope, as the weather has so much prevented my use of the telescope?

Nice EPs but they look like they need a visit with a Puffer Brush ?

Use the telescope parameters, although these can be exceeded. f/5 telescope, then take for granted a 5mm eyepiece as your guidline highest magnification in good conditions, double this for the sweetspot, and treble for the lowest power. But dont go too low, ie beyond your pupil size. I chose a 32 mm low power eyepiece and satisfied with the result. I can reach 3.2mm on the Moon, but between 6mm and 12mm is great on my scope. The size of the image on my scope is small, and Barlowing increases the image size, but does'nt always improve the detail in the larger image, whereas a larger aperture in my case would improve the detail / resolution.

Thank-you back.

I think the main reason to purge optics is to prevent internal fogging or the chance of anything growing in there, fungus? ( I've seen this in old binoculars? ) Not only that, but if the optics are water tight, they are generally air tight so nothing can get inside. It probably wouldn't spoil the view, but will just annoy you if you knew there was something inside! I know Nitrogen is an Inert gas which means it doesn't carry water or reacts with whatever it comes into contact with.

Phew! the 27mm is not a Starguider? Wallet back in pocket

I find the actual task of collimation straightforward. Understanding the theory and deciphering what you see through the focuser during collimation is what scares most folk away. I'm fortunate enough from training to become proficient with the eqipment i had to use. Repetitive stripping and re-assembly of the components instills confidence in the product. This just comes with practice. Understanding for some folk cannot be learnt just from reading a guide book. I reckon most folk given a one-to-one session of no more than 60 mins, if they are unfamiliar with collimation, and they'll wonder what all the fuss was about. Like most things in life, once you have been shown, you wont look back. There are several videos on the Tube, perhaps this may be more helpfull for some folk I cant read music or play a guitar, but I can re-string and tune them! and tested by a more competent person, they found no fault. There's no quick fix for overcomming any fears, just be patient, relax and have a go.

For some folk, collimation is not the best way to spend their time, and the fear builds, with the feeling of guilt/failure if it doesn't appear to work. Take your time, and keep reading the subject. Only when you have done the task a few times, does it become apparent? Understanding the theory, which way the mirrors move during collimation, and what your actually looking at through the tool can all be daunting at first. You will at some stage, become proficient in the task. I have used the 35mm film cannister method ( not just the cap, you actually need to drill a 1mm hole in the cap, but REMOVE, cut-off the base of the cannister!) then fit the tube/cap into the focuser. This method works very well, but could I improve? I bought a Next Gen Laser, that needed collimating, it works, but due to the sloppiness of its fit, I'm certain it's not 100% accurate? ( equal blame here between the body of the laser and the inside diameter of my focuser assembly possibly ?) I now prefer the Cheshire sight tube. Still could have the same sloppiness of fitting, but this one feels tighter in the focuser than the laser. I still use what is known as the Barlowed-Laser method, to check my primary mirror when away at a viewing site. This method does not require such a tight fit in the focuser tube, so the positional/fitting error is non existent now. You need to find which method you like and stick with it.

I simple windbreak, the type you take to the seaside will suffice, as long as its high enough. The bedouin wrap sounds good too, just mind you don't cover the aperture?The Dob tent is a toilet/utility tent from Go Outdoors

lostpleiad.........I find that if my eyes are averted from the light pollution, then the image from the telescope appears to look better, this is just by having the eyes dark adapted. I have a snood made from camping underlay foam, but often just forget to apply it to the scope. My telescope is looking through the light pollution, rather than directly at it, but my eyes are getting the full glow when looking around the garden, but there are dark areas where I can sit, and my eyes are shielded to some degree, from direct light sources. The best results from my garden is when in/using my my Dob-Tent? A dark bath towel over my head also helped to keep some of the light at bay, and reduces the cold around the face, before the tent arrived. Seriously expensive eyepieces are better corrected off-axis(no edge distortion of the image) and suitable/better for faster focal ratio telescopes and may have wider views, but they wont rid your light pollution. As Moonshane points out, could you tell if there was much difference? I used to visit nearby Clanfield? I thought it had dark skies, but with so many new dwellings there now (since my Days) that I would assume it has more skyglow now?

I think most folk would accept an eyepiece over a Barlow, but we all have Barlows? Try this calculator. http://www.stargazing.net/naa/scopemath.htm to give you some idea of whats possible, against practical, whilst observing the limits! Work is calling!

Yes only in 2". This gives you the very good 70° afov. However I now believe your telescope will only accommodate a 1.25" EP, so back to the BST 25mm as a reliable 60° afov EP. That's the longest focal length for a BST Starguider. £49.

No Barlow at all would be the best option as there is less glass in the focal train? Barlowing helps build your EP selection by effectively letting you use one eyepiece covering two focal lengths. Try barlowing the 8mm or the 15mm on the Moon, see for yourself. Say you use the 15mm, the image will be closer when Barlowed ie 7.5mm but unless you see a discolouration I would not bother about changing the Barlow.

Given that choice, knowing what I have, and knowing that we have different scopes, I don't think you would be unhappy with a 32mm Panaview. However your telescope suggests an EP of between 28mm to 14mm as your optimum EP! the minimum magnification of about 19x power equates to a 47mm EP and your highest magnification suggests 260x power with a 3.5mm EP. Again this is almost the limits of your telescope, I would suggest to try and stay inside the limits for the better results. You have near as dammit the 7mm by way of the BST 8mm, and with your present 2x Barlow , you could Barlow your 15mm BST giving you 7.5mm. so I wouldn't necessarily buy a dedicated 7mm just yet? Optimum could suggest anything around the 25mm mark, so at some time, yes a replacement BST 25mm will give you a wider field of view over the SW25 and 47mm is just a waste, so maybe be happy with the BST 25mm again, or a 28 or 32mm Panaview. As these two Panaviews are the same price, I would opt for the larger focal length.

craigfoot......... I think you can manage without it? My replacement for the SW25mm was my BST 18mm? The BST25mm came to me second hand. The SW25 is a reasonable EP but with only 50° afov. Whatever you buy will transfer to telescopes of the future? If you were to go down the 200mm route the 32mm panaview would be a nice eyepiece, as would a 6mm WO SPL as your primary Planetary EP. Only suggestions mind you. My 5mm BST came as a replacement to the 6mm TMB Planetary II which was not to my liking. The 6mm WO is nicer, but I really need to get out one night soon, to fully appreciate the EP. My new work is taking my spare time away whilst I study?

............from my garden, I find it hard to capture M31 Andromeda. Its there, but just a hazy small smudge? I go to a darker site and wow! the difference is staggering. The SW25mm I have is good (like yours) but now, I feel, just not wide enough to take in M31, there's that much difference, so I needed the wider view. I chose the Skywatcher Panaview 32mm for my wideview EP. And during last Weekend, whilst comparing a TeleVue Plossl, I used the 32mm and located two new Galaxies M81 & M82, just not visible from my light polluted garden. I chose the 32mm and my 6mm using help and advice from several SgL users, and for my f/6 telescope, and MY EYES only these two EP's are very good indeed, they match my telescopes specifications, and are comfortable to use with my eyes. What works well on one scope, may not fare so well on another. But what you have at present seems to work quite well. My first telescope was the Celestron 127EQ, I see so much better with my 200P/8" and using my present EP's in the Celestron, doesn't help the Celestron a great deal, I have needs that exceed the 127s ability, so I just use the Skyliner.

Ok.........SkyWatcher Explorer-130/900 EQ2 Telescope gives F900/D130=f/6.9 so your looking for an EP of approximately 7mm? (My Skyliner is actually an f/5.9 rounded out to 6) So drop the 5mm suggestion in favour of the 8mm BST you already have or buy a dedicated EP of 7mm for your planetary use. The BST 8mm will give you 113x power and an exit pupil of 1.15mm If you Barlowed the 8mm, you would have 225x power and 0.58mm exit pupil. pushing the limits here. A 6mm EP would give 150x and 0.87mm exit pupil. A 7mm EP giving 129x and 1.01 exit pupil. (f/6.92) rounded to f/7? look at your text above in yellow. You already have 8mm and 15mm ( only 1mm out on each EP!) and already getting great views. The reason being your just about on the mark with EP focal length and aperture. Match the f/ratio for your highest magnification ie. 6.9x or 7x rounded (the 8mm is closest) double the f/ratio for the 'sweetspot' so say 13.84mm , rounded to 14mm ( close again with the 15mm EP) I'd stick with those EPs for now, and possibly just get something wider if you think you're 25mm is no good. The extra cost now to change 1mm of EP focal length may not be the most sensible use of your money. You could still buy yourself a dedicated 7mm or just put your money towards a bigger telescope? Your telescope has limits, which are quickly reached. Mine too.

Not sure! When I enter your telescope details, "Explorer 130 eq2" I see F-650 and D-130 giving me an f/5 ratio telescope. I need to confirm I`m looking at the same telescope, before recommending an exact size for the EP. Off to work now, will get back later, unless someone else chips in to help you.

Correct.......but a 4mm alone will be pushing the limits of your telescope, and may only be useful for the Moon. My suggestion to Barlow the 10 or 8mm gives you 5 & 4mm if/ when needed. A good planetary eyepiece matching the equivalent focal ratio of your telescope will give an exit pupil of about 1.0mm giving better image quality. The Uk weather/atmospheric conditions limits what we can see. My telescope at 200mm is good for 200X power, any more is pushing it a bit, likewise a 130mm is good for 130x power. This doesn't mean you can push to 200 and get away with good views all the time? The Moon Yes, throw whatever power you want at it, but everything else has limits, that we reach oh so quickly. and too much degrades the image. a 5mm 10mm and a 35mm all hit the sweet spots of your telescope working off the focal ratio f/5. I said 7mm earlier, disregard. I believe your scope to be an f/5. Your standard SW 25mm should be ok to use. I chose the 32mm Panaview as my highest focal length. The 8mm you have, as you know is just fine, so you may get some good use from a 5mm. Now my 6mm WO SPL is a fine EP for my Planetary use, but we have different scopes. I think between the 8mm(112.5x) you have and possibly a 5mm (giving 180X power), you should be ok. So many combinations, and so much to absorb in decision making. I said 4mm is pushing limits and 5mm ok!.......1mm can really make a big difference to the telescope