NGC 1502

My TeleVue Pronto objective was a bit grubby and in need of a clean. This included the rearmost lens surface, inaccessible without removing the lens cell. Some folk worry about removing a TV refractor lens cell but it’s really no problem. I don’t know if it matters, but I placed small stickers on the tube and adjacent lens cell to enable the cell to be replaced in the original orientation. All TV refractor lens cells are secured to the tube with 3 hex head screws filled with a semi-hard substance. It’s not difficult to clean out the hex heads to enable removal with an allen key. As I’d done this years ago, it was a 2 minute job to remove the screws and separate lens cell from the tube. Note- the lens cell complete with elements remain intact as a unit. My preferred lens cleaner is Lens Bright as supplied by Specsaver opticians. Used with a clean micro fibre cloth I’ve found it works better than any other lens cleaner I’ve used. This includes 99% pure IPA. Having used a bulb type puffer to remove any dust I carefully cleaned the rearmost and front optical surface. A couple of tries left pristine optical surfaces. I refitted the cell to tube with the 3 allen head screws. Before tightening, the cell can be adjusted for collimation. However I have previously found that if I pull the cell back onto the tube, then tighten the screws, collimation is spot on. Presumably that’s because everything was accurately and squarely constructed. So, a 2 minute job to replace the cell. Last evening was unexpectedly clear at my location, so I set up the Pronto at dusk. First up was Jupiter as darkness fell. Nice and crisp at up to 120x, although 96x was even crisper. 150x and above was too much as I’ve always found with the Pronto. My test object for collimation was Zeta Orionis- Alnitak, the easternmost belt star. At 120x split suspected, 150x split confirmed. I tried my 2.5mm Vixen LV for 192x. In the not great seeing split definitely observed in steady moments. I’d estimate the secondary star was seen about 30% of the time in steady moments, but a blur most of the time. Castor. Using 150x, Castor A & B were 2 hard Airy disks with perfectly concentric first diffraction rings, beautiful sight😊 Now, I fully realise that my objective cleaning hardly improved the view. But it did satisfy my OCD with a pristine objective lens! Ed. Note- All allen heads on my Pronto accept Imperial allen keys. I don’t know if that applies to all TV refractors.

Yes that’s an ideal test object for scope comparison. I have an 80mm f11.4 Vixen achromat, it will split Tegmine as a double but the third component eludes it. It will be interesting to hear if the extra aperture is successful😊 Let us know what you see!

Wishing you all the very best with the Vixen. My only comment is to be cautious about selling the Tal. It will take several sessions with the Vixen to fully evaluate. Best is if you can use both scopes at each session on a variety of objects. But it’s a great “problem” to have😊 Ed.

Whilst I value the Sky at Night program and the excellent presenters, for me it’s nowhere as good as when Patrick Moore was around. Call me a dinosaur if you wish I have a fine armour of protective scales😁

I’ve been using my smallest scope recently, my TeleVue Pronto. That’s because it’s not seen much starlight recently and it sets up in a jiffy just like its name suggests. Double stars are one of my favourite objects. The whole sky is stuffed with them at all seasons. They show up well in our light polluted skies and when there’s a full moon around as last night. Started off with one of my favourite triples, Beta Mon, east of Orion’s Belt. Suspected double at 18x…..at 44x double confirmed, triple suspected……at 80x and up triple confirmed a lovely sight. On to Alnitak, easternmost star in Orion’s Belt. My ED80 splits the A/B components if the seeing is half decent. But for some reason I’ve never tried it with the Pronto until last night. I got a suspected split at I20x. Put in my 2.5mm Vixen LV for 192x. I was delighted when the split was confirmed 😊 Unlike some I’m fortunate not to be hampered by eye floaters at tiny exit pupil sizes. I was out with the Pronto the previous night too, that’s 2 clear nights in succession, not had that for a very long time! Ed.

Indood I Dee, oops I meant Indeed I do😊

Definitely agree, this is very often overlooked.

You might try SGL member Peter Drew. If he doesn’t know a supplier then no one does😊

12” and Bortle 4? I am not envious. I am VERY envious indeed😁

Clear Sky Anger? Last night Clear Sky forecast said it would be wonderfully clear in SE Essex. If that’s their idea of clear then the clouds would be solid lead when they forecast clouds……. Disgruntled from SE Essex🙄

I share your sadness at untimely the loss of David Lukehurst. One solution is to DIY your dream telescope. If you’re a DIY sort of person it’s not too difficult to configure Newtonians/Dobsonians to your own design. There’s a vast amount of info on the ‘net. Making the primary mirror is a step further. If that’s not your thing then maybe patiently waiting for something to come up on the used market, or placing a wanted advert. Recoating facilities are available in the UK. I’ve never made a Newtonian mirror, but have constructed and modified them lots of times. Great satisfaction comes from using a scope you made yourself. Dobsonian mounts are basic carpentry projects. Ed.

A StellaLyra 30mm would be a great upgrade from a stock 25mm as supplied with many scopes.

Indeed….we all know that TeleVue make excellent eyepieces. But I cannot understand why they don’t do adjustable eyecups like everyone else…..a well made screw type adjustable eyecup…….simple and solid. Even the BST Starguiders have that.

Agreed…..it’s often said it doesn’t matter what a scope looks like, you can’t see it in the dark….. However, during long cloudy spells you can set it up in daylight….drool….then admire how handsome it is😁

Looks like Dudley Fuller to me😊he started Fullerscopes…….then teamed up with Broadhurst & Clarkson….BC&F was born……back then you could buy mirrors, cells, focusers, spiders……all the stuff needed to make a fine telescope. Now most of us splash the cash and miss the pleasure of observing with an instrument you put together. Showing my age now…….😩……..some of us on here (not me) we’re the REAL DEAL and made their own mirrors….my respect if that’s you!

Interesting thread resurrection😊 I’m inclined to think it would take a true optical craftsman to refigure to the same high standard as the original. I also have a 6” Newtonian mirror made by Henry Wildey, a contemporary mirror maker of the same era as David Hinds. A while back I was very tempted by an AstroSystems 10” on sale at ENS Birmingham, don’t know if it’s still available, scared to look because my temptation will be beyond resistance😊 Yet more thread drift!

Great offer for a lovely scope. But a complete pain for someone trying to sell a used one☹️

Here’s my dream scope- One year at Kelling star party I was privileged to observe through Liverpool Astronomical Society 30” Dob. The night was not especially transparent, but the spiral arms of Messier 33 were very obvious indeed. This 30 second observation was very probably all I’ll ever get…..but what a fabulous half minute that was😁

It sounds like the first reply from Lee has good advice. One thing you could try is joining a local astronomy club, it’s likely they will know of good observing sites. You may find somewhere good by searching yourself, however it’s possible you will actually find a lover’s lane with people arriving and leaving with headlights blazing, and wondering what on earth you’re up to! A local astronomy club may have a more secure site behind locked gates. I’m not envious of Cornwall skies, I’m VERY ENVIOUS INDEED😊 Ed.

Must be a really tough choice to make, I sincerely hope it works out ok for Dave. Ed.

Indeed, this is a particular problem with a Newtonian on an equatorial mount. When slewed to different parts of the sky the focuser/eyepiece can be in very awkward positions, like pointing towards the ground. Rotating the tube can make the eyepiece accessible. The above is not a problem with refractors, SCTs & Maksutovs with a star diagonal on an equatorial mount. It’s easy to rotate the star diagonal/eyepiece to a convenient position. This is one of the reasons why some of us prefer alt-azimuth mounts like Dobsonians, the focuser/eyepiece is much more accessible in any part of the sky.

For my several small refractors I’ve tried all sorts of alt-az mounts over the years. Before I continue please understand that what suits me may not be good for you. What works for me is this- I’ve long ditched the idea of slow motion controls. They always seemed to be in the wrong place, especially as they both have to be used at the same time, more frustrating at medium to high powers. I much prefer holding the star diagonal and hand guiding the scope. The diagonal is always right there, immediately under the eyepiece I’m using. However, for this to work well it needs a well balanced scope on a smooth moving mount with just the right tension on both the altitude and azimuth directions. The above works well with my 3 small refractors- TeleVue Pronto, Skywatcher ED80, Vixen 80mm f11.4 achromat. Ed.

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.