NGC 1502

As above- sort out the secondary with the Cheshire/sight tube first. When you’re ok with the secondary use the collimation cap to sort the primary. Whilst you’re using the collimation cap check that all primary mirror clips are visible and equidistant within the view. Fine tune the primary with a slightly defocussed star at night using medium/high power. Are you absolutely certain your laser is collimated and does it fit the focuser without any slop? It’s always possible to accurately and precisely decollimate your scope with an iffy laser…. Ed.

Please don’t stress, both of those scopes will be great. As you’ve already bought the 120, if it were me I’d just enjoy using it. It will excel for low power wide field viewing for many objects. Whilst it’s not ideal at higher power especially bright objects, that’s not to say it will disappoint if you can accept what it does. Perhaps research how to cope best, perhaps a filter for bright planets, or try stopping it down with a DIY aperture mask. Enjoy great views of Jupiter, not perfection but satisfying none the less. Learn to ignore the blue/purple halo, concentrate on what’s good rather than lack of pristine views. With the right perspective a great instrument for many years to come😊 Ed.

Sometimes it’s a tough call when to clean. But looking at your first pic most of us would say the time had arrived😊. Done methodically and carefully nothing to stress about.

I get that, however higher powers produce smaller exit pupils and lessen the need for using glasses. With my 10” f4.8 my 11mm and 7mm Naglers give 2.3mm and 1.48mm exit pupils. Depends a lot on the observers personal eye issues.

If you didn’t like Radians then it’s likely you won’t like Delites. I’ve used a friends Delites at my clubs dark site, only perceived difference with my Radians was the weight, Delites much lighter, that could be an attraction for you. The combination of Panoptics for low power and Delos for medium to high is a match made in heaven. Panoptic 27/35/41 have good eye relief and 68 degree apparent field so are effectively low power Delos.

Other things to try- make sure that primary cell to tube bolts are secure, also spider to tube connections. It’s well known that mirrors should not be clamped or pinched. However if there’s too much freedom for the primary mirror it can easily shift. Primary mirrors can be carefully shimmed so no pinching occurs, but not excessive freedom either. My 10” f4.8 OO UK Dob rarely needs collimation adjustment, and I’m fussy to get the best views.

Just a thought…..as your question relates to imaging maybe a post in one of the imaging sections may get a response. Welcome to SGL😊

Previous post contains good advice, depends how much tension or friction is in the altitude bearings. I made an altitude brake similar to the optional brakes on Orion Optics UK Dobs. I can very easily add just the right tension to allow smooth movement and yet eyepiece changes from 1kg eyepieces to 250g eyepieces without any problems at all.

I can vouch for Henry Wildey mirrors. About 5 years ago I purchased an unusual specification mirror from a retired staff member at Telescope House (BC&F). The engraving on the back said it was made in 1954 by Henry Wildey. But the engraving included the unusual specification of this 6” mirror as 22.5” focal length. That’s a focal ratio of F3.75…….I’m guessing this must have been a special order. Back then most people wanted a 6” F8. Before proceeding with a recoat and building an optical tube I had the mirror tested by a club colleague who has an optical workshop. Superb optical figure was confirmed, Henry must have been very skilled at his job. The result is an exceptionally compact RFT….Rich Field Telescope😊

Your budget would buy a brand new 8” Dobsonian with enough left over for a couple of better eyepieces. Having said that, you will have to learn the sky, manually find and hand track objects. But Jupiter is very easy to spot. Details on Mars much more tricky.

If it were me I’d get a full refund if possible. Then check out our sponsors First Light Optics (link at the top of the page) and purchase a brand new ready to use 8” Dobsonian. Several brands to choose from.

Very tough call to decide for someone else! You are likely to get a wide range of differing advice…. Here’s mine, for what it’s worth. A friend bought a Celestron 100az against my advice. The build “quality” was absolutely appalling, cheap and shoddy. It’s now gathering dust rather than starlight. The 4se is much better made. However please note that with entry level hi-tech scopes much of the cost goes into the electronics and less into the optical parts. But used with care it gets the job done. If it were me I’d sooner buy a 6” or 8” Dobsonian where much more of the cost goes into the optical parts and much less into the basic but effective Dobsonian mount. BUT- to effectively use it you have to learn the sky, manually find and track objects. Like I said, tough call giving advice……

This may not what you want to hear- If you want your scope to fit in a back pack that’s a very tough call, don’t forget you need some sort of mount for the optical tube. Perhaps one of the smallest table top mini dobs might be your best bet. With a bit of DIY it’s possible to make the Dob base to be easily taken apart and put together again, certainly not ideal especially if it’s dark. But unless you want to lay on the ground to observe then you have to find something to rest the scope on. Sounds easy but not so easy in practice. If it were me, with the restrictions of a back pack I’d choose binoculars, 10x50s recommended.

Good luck with the search, usually new moon in March is recommended as the best time to try. Many Messiers don’t need a large scope, especially if your skies are good. M74 and M76 are often mentioned as being difficult. However I find M76 Little Dumbbell quite easy with a UHC filter from my light polluted back yard. Not so with M74, not a sniff in spite of many tries from home with my 10”. But once whilst on holiday in the Peak District with a 6” F4 travel scope M74 was readily seen near Eta Pisces. The most southerly Messier M7 was easy from my club’s dark site with a 70mm TV Pronto just a few degrees above the southern horizon.

As already asked, what eyepieces do you already have? Based on your answer then advice about barlows can be made. If you only have the stock eyepieces that came with the 8” Dob, then most of us on SGL would suggest upgrading those first, rather than buy barlows. Please don’t make the easy mistake of thinking that very high power is best. Very high power with an 8” Dob is 250x and above. Very high power may occasionally be useful but not very often.

Tough question to answer! There’s a vast number of good beginner targets, even from light polluted places. I’d suggest you buy the book “Turn Left at Orion”. It’s a brilliant book, stuffed with all types of objects at all seasons of the year. Welcome to SGL😊

Hello Guy. Sounds like you’re mostly happy with the 12” Dob, apart from setting it up and cooldown. Please don’t forget that more aperture equals greater resolution for planets and double stars. You mention the 12” is kept in the garage, so assuming no heating in there that will help with cooldown. Does it have a cooling fan for the primary and do you use it? How about lockable castors on the Dob base, that would help with moving it to your observing place. Ed.

If it were my choice- Skymax 127 for Lunar/Planetary and keep the ST80 for a wider view. Those 2 scopes nicely complement each other. Cooldown for the 127 should not be long with the suggestion already mentioned. Option 2. Have another try at making a shield for the H 130, and live with the helical focuser. Many have fixed the focuser with PTFE (plumber’s) tape. Ed.

Yes, in general the above is good advice👍 However, if a youngster has decided they want a telescope they will be disappointed if they don’t get one. Binoculars, even if actually a better gift, it won’t be seen that way. They really need an experienced adult to demonstrate how effective binoculars can be, how rewarding binoculars can be. Definitely agree that for a beginner, an EQ mount is a hobby killer, especially one of the cheaper models on a wobbly and flimsy tripod. However, a flimsy and wobbly alt-az is not much better, even though it’s far easier to understand. An 8” Dob could well be a lifetime scope with a few upgraded eyepieces like the value-for-money BST Starguiders from our sponsors, FLO. To significantly out perform an 8” Dob it takes a 12” to give an obviously better view. But a 12” is quite a beast to lug around and may not see much use. If it’s on castors in a shed adjacent to the observing spot, that works well. Ed. Edit- lockable castors!

Apart from (possibly) the 32mm you already have an excellent set of eyepieces😊 If it ain’t broke…..don’t fix it! Ed.

Lots of good advice above…… I. Don’t have astronomy as your only interest! Have another passion for when it’s cloudy, or freezing weather👍 2. An old saying with astronomy- the best scope is the one that gets used! If it’s too heavy, too complex and time consuming to set up…..that’s a hobby killer for sure! 3. If your scope is too heavy/complex/hassle……have a second much less hassle scope. 4. Be very wary of selling up…you’ll get much less than it cost, unless you bought it second hand for a good price. 5. If in spite of number 4 you do consider selling up…..wait a few weeks to make certain it’s the right decision. 6. Don’t forget that some folk who have astronomy as a passion don’t have a scope, their interest lies in a more academic direction, absolutely nothing wrong in that😊 I bought my first scope in 1979, I’ve been through all the above and I’m definitely not packing in! Cheers from Ed, 75 and still loving it!

Thanks, yes that’s very similar to what I found👍

Just found a photo of Herschel’s 6.25” 7ft focal length reflector with a brass sliding sledge focuser, but unable to post a link. The tube is mahogany.

I seem to recall that type of focuser as being a very old idea. A replica of one of William Herschel’s reflectors was on display several years ago when I visited the Herschel Museum at Bath. The “sliding sledge” focuser was a design feature. It works as long as it’s well engineered. But I’m thinking that a fixed secondary with conventional focuser is simpler and fully effective. Anyone know if there’s any advantage with “sliding sledge” focusers? Ed.

As suggested in another post, perhaps this scope had suffered a whack during transport. I once bought a second hand TV85 from someone I trust. When I tried it the collimation was way off. All TV refractors have their lens cell secured to the tube with 3 locking screws. If the scope suffers a sharp knock, the lens cell can shift relative to the tube. If you’re careful it’s a DIY fix. The sealant on the heads of the 3 lock screws must be removed and the screws slightly slackened. Using an artificial star, or defocussed real star, the cell can be nudged into alignment, then the 3 screws tightened. The above wouldn’t stop me buying a TV refractor because I think they’re great. But there’s better ways to secure a lens cell to the tube. My very early model Vixen 80mm f11.4 lens cell simply screws onto the tube. The cell incorporates 3 pairs of push-pull screws. Simple and precise.