NGC 1502

My 10” Dob regularly gets transported by car to my clubs dark site. The tube assembly fits across the back seat.  The scope has thick altitude rings and I use one of those to tie to the headrest supports with thin rope. I find that’s easier than using the rear seat belts. The mount is laid in the boot along with my observing seat, eyepiece box, and other accessories. A large plastic bag contains extra clothing, that can go anywhere. It takes no longer than 5 minutes to load up. As the back seat has standard upholstery no more protection for the tube is needed.  
 

Ed.

On 20/07/2021 at 12:38, John said:

This is not in anyway intended to be a controversial topic I hasten to add - I'm full of admiration for those who try and capture images of the heavens and often the results are really worthwhile

I've just noticed over the past, say, 18 months how many folks are seeking to acquire images now in one way or another, through dedicated astro cameras, mobile phones DSLR's etc.

The urge to capture seems to be stronger than ever.

I've dabbled when the comet was around last year and with the occasional crude "mobile to eyepiece" snapshots of the moon, sun etc but I'm not yet tempted to get any deeper into imaging despite rather a long time "at the eyepiece" as an observer

Is the trend towards imaging growing or am I imagining it ?

 

I’m very late to this thread and I’ve not read all of it…..so apologies if others have made similar comments….

I’m strictly visual because I really enjoy it.  At times I’ve felt like I’m a dinosaur with all the attention that imaging gets.  My local club in Essex has a wide spread of different ways to do astronomy.   Hard core imagers, casual imagers, hard core visual, casual visual, hard core armchair, casual armchair…….some a mixture of all that.   My impression is that it’s fairly evenly spread with the way our members do astronomy.

I think that the appearance of imaging being more predominant is because if someone has spent many hours and loads of money to get their fabulous images then they want, quite understandably, to share that image. Plus because of all the blood sweat and tears they’ve gone through especially with how it’s done they often, again understandably, share their knowledge and ask questions between us all.

But take a look at the wide range of kit that astronomy vendors, like FLO, have for sale. There’s a shed load of visual equipment for sale. Vendors can only survive if they offer stuff that sells, if they continually stock visual equipment then there’s a reason for that, and the reason very obviously is because people are buying it.

I absolutely don’t mind if astronomy attracts lots of imagers. They are very well catered for by astronomy vendors, that keeps them in business and means they can also stock visual equipment……so we’re all winners in what’s available to buy.

So let us visual only astronomers celebrate the wide range of folks that our fabulous hobby has in its ranks👍

Ed.
 

28 minutes ago, banjaxed said:

I have an app that only predicts weather conditions for the next 2 hours. Trying to predict conditions beyond that is only guesswork IMO.

Any chance of a link please 👍

Generally speaking refractors hold collimation very well, and some people favour refractors for that reason alone.

Assuming a refractor has been properly assembled during manufacture then I’d expect it would be fine when received unless serious abuse had happened.  The condition of the packaging should give a good clue about how well or otherwise it had been treated during transportation.

You’ve mentioned you won’t do anything until you’ve star tested, and I think that’s essential. Hopefully all’s well. Of course if you’re using a diagonal it’s possible that was incorrectly assembled or suffered damage at the same time something happened to the main instrument.  Observing straight through without the diagonal would eliminate that, uncomfortable but you’d only need to do that once.

So if it were me, I’d star test, probably it’s all ok. If not, repeat the test to make absolutely certain there’s a problem before considering what to do.

Ed.

Even if you hadn’t said what your sketch of the Double Cluster was, I’d have known.  The “parachute” asterism in one cluster, the more open nature of the other with a “hole” in the middle.

The Owl Cluster, that’s recognisable too, one “eye” brighter than the other, the wings, narrow body…..

Excellent, keep up the good work!!

Ed.

16 hours ago, John said:

I've just owned 2 Radians - a 4mm and a 3mm. This was a few years ago now. I enjoyed using them although I did find that the 4mm handling of off axis light when observing the bright lunar limb rather odd.

They were sharp, well made and comfortable to use though.

 

Those of us who owned the commonly available eyepieces in the 1970s & 80s would have been astonished to have known what’s available today.  The high power eyepieces back then had virtually zero eyerelief, tiny eye lenses, and a very narrow apparent field….  Radian, DeLite, and loads more, 20mm eyerelief, 60+ degree field……..supreme luxury indeed!!

5 hours ago, Louis D said:

Have you ever noticed SAEP (kidneybeaning) in your Radians?  It was the first thing I noticed about them viewing through a telescope in the daytime in a shop in 1998 when they were introduced.  It immediately turned me off to them, and I went with Pentax XLs instead which display no SAEP to my eye.

I’ve heard several reports of eye placement problems with Radians, so accept that some have found that. But as long as the clunky eyeguard is properly deployed I don’t have any issues like that.

I’ve only ever had one Pentax eyepiece, that was the 10.5 XL, one of the range you mention. I wish I’d built up a set of them, the 65 degree apparent field doesn’t sound much more than the Radian’s 60 degrees, but it was quite noticeable to me. And the screw type eyecup a simpler and better design. When I compared the 10.5mm XL with the 10mm Radian, I found the Radian a bit sharper off axis, not a deal breaker but it was there. Overall however I rate XLs above Radians. I have looked through someone else’s 10mm XW and found it superb.

As always eyepieces are a very personal thing. I’ve had a scope since 1979, and doubt if my eyepiece journey is over…..

Ed.

A brief comparison between budget and premium eyepieces.

I have all focal lengths of the long discontinued TeleVue Radians apart from the 3mm. A recently acquired used BST Starguider 18mm joined  my BST 12mm. I got the BSTs to keep in the case with my Lunt H-alpha scope, this allows a quick set up to catch a break in the clouds.

Last night was clear at my location and my 10” f4.8 Dob was out for observing. It doesn’t have a coma corrector. I thought a comparison would be interesting. First I compared the 18mm BST with the 18mm Radian. Sharpness in the centre of field, no discernible difference. Off axis, the BST was noticeably less sharp getting worse towards the edges. The claimed 60 degree field of both eyepieces seems correct. The BSTs field stop was reasonably sharp but not quite matching the razor sharp Radians. Eye relief of both eyepieces fully adequate for me, I don’t wear glasses for observing. The longer 20mm ER of the Radian does allow the observer to more easily get their eye too close leading to vignetting. The shorter ER of the BST makes it a tad more difficult for that to happen. Inexperienced observers sometimes think that’s a fault, but it’s just a misunderstanding of how to use long eyerelief eyepieces. I’ve yet to use any long eye relief eyepiece from premium manufacturers that doesn’t vignette if incorrectly used. The adjustable eyeguard of the BST is in my opinion simpler and better than the clunky Instadjust. The Instadjust is easy to fix if its too loose but again in my personal opinion is a clunky solution for an adjustable eyeguard, as is the sliding eyeguard on Delos and Delite eyepieces. Of course a clunky eyeguard doesn’t mean that an eyepiece is not absolutely superb in all other ways and very definitely worth having 👍

Comparing the 12mm BST with the 12mm Radian, the comments above are the same except for one major thing. The BST almost but not quite matches the off axis sharpness of the Radian. That’s probably because the 12mm BST has extra lens elements within the chrome barrel that the 18mm BST doesn’t have.

I also tried the above with my elderly Vixen 80mm f11.4 achromat.  Many readers will know what I found. In that scope both eyepieces are excellent and there’s no reason, in my opinion, to use anything more expensive than the wonderfully inexpensive BSTs!

Ed.

Good advice already given.  Some extra tips (pun intended 😁)

To avoid overheating the drill keep a pot of water handy to cool the drill.

If both cutting edges are not precisely the same, the drill will make a hole larger than its nominal size.

You have to be exceptionally skilled to properly sharpen drills less than 3mm diameter.

BTW, the guv at the factory I worked at in the 60s demonstrated to me how its done. Back then the guv often had come up through the ranks from the factory floor so knew how to do it, that’s why he got promoted 

Ed.

Great you found Galvoptics helpful, that’s exactly what I’ve experienced on several occasions.

When replacing the mirror of course it must never be clamped in place. But the mirror clips need just a tiny clearance from the optical surface. Paper thickness is fine. A large gap allows the mirror to shift and loss of collimation more likely.

Go carefully and you’ll be fine.

Ed.

Galvoptics at Basildon are a family run business and great to deal with. Their turn round times do vary according to what work they have, but they’ve always given a lead time when asked, and either kept within that or were quicker.

My local club’s 16” Dob had its mirrors coated there in 2003 and are still fine after several washes. They also coated a member’s own 20”.

Ed.

I live in Southend and for convenience have used Galvoptics (Image Optics) at Basildon several times, always a reliable service. The big advantage (for me) is I didn’t have to pack the mirror to withstand the earthquake wind and fire of a postal service or pay for it. I delivered and collected myself. A phone call to say when you’re coming. Then just find a piece of hardboard or ply, cover with kitchen roll, then tape the mirror face down. Mark clearly the service required (strip/recoat/overcoat) and contact details, say you’ll collect when done.

On collection my mirrors have been taped to my hardboard and acid free tissue has been used in place of my kitchen roll.

Good job, recommended. Prices available online.

Ed.

With a 6” scope many galaxies can be seen as fuzzy patches even from town, but if you can get to darker skies that’s better.  Sky transparency is important, if it’s “clear” but hazy, or a bright moon is up that hinders greatly.

A Telrad or similar like a Rigel Quickfinder is great, or a standard red dot finder. As mentioned use low power to find your target because that shows a larger area of sky.

It’s possible that one of the reasons you don’t see dim fuzzy objects could be because you don’t have it in focus. Before trying to spot the galaxy focus on stars first. It’s difficult to focus on a dim fuzzy patch.

Finally not many of us have ever exhausted the possibilities of a 6” scope so please don’t think you must upgrade to enjoy great astronomy. Perhaps at some point you might upgrade but there’s definitely no rush!

Keep trying and soon you’ll be spotting loads👍

Ed.

2 hours ago, siennax said:

i’m fairly new to telescopes and i’ve assembled it properly but i can’t see anything through it. i’ve taken off the cover on one end but when i look through the eye piece it’s black but when i take out the eye piece and look through the whole i see an image but it’s very tiny.

A couple of possibilities- from which end of the scope did you remove the cover?  You need to remove the cover from the end nearest the focuser where the eyepiece fits. Sometimes there’s a smaller circular section in the middle of the cover, but the whole cover must be removed.  Occasionally when others have been trying to look through my scope they’ve said they can’t see anything, the problem was they didn’t have their eye in the right place, it needs to be central on the eyepiece.

1 hour ago, Starslayer said:

Erm - no.  The stock set up does not flip anything.   Edit - maybe the stock one IS a correct image diagonal as supplied. 

Ok my apologies, perhaps I should have said that the stock diagonal traditionally supplied with SCT’s flips the image left to right but doesn’t invert. Sorry if my original post confused.

Ed.

38 minutes ago, Starslayer said:

 

What I do not understand is why therefore the stock visual back that came with my scope also shows the image correct in both planes notwithstanding to me it looks like my 90 degree 2" albeit smaller at 1.25"

Is there something else about the way a visual back is constructed and works that I am not only totally missing but also cannot find an answer to in the world of google?   Is a visual back not a 90 degree prism? I do try and find these things out before running to you guys. 😇. Thank you. 

 

The stock diagonal used with your SCT will flip the view left and right but not invert it. This is the same whether it’s a prism or a mirror in the diagonal.

It’s possible to purchase a “correct” image diagonal but the problem with that is it degrades the image.

A triangular shaped infocus or slightly defocussed star could mean a pinched objective lens. With a refractor objective try carefully undoing the retaining ring around the front lens a small amount. Test again at high power when you can.

When slackening the retaining ring be ultra careful to not damage the lens.

Hope you sort it, Ed.

As mentioned by others, the link to Gary Seronic is brilliant. Gary cuts through all the information and mis-information that’s unfortunately widely available by so called experts.

Ed.

On Thursday evening I bought an eyepiece from this well known online retailer. I’d been looking for this particular focal length from a long discontinued range.  The price was a bit high but as I’d been looking for ages decided to go ahead. For postage I chose ENS courier 2-4 days.  The tracking worked well with a 1 hour delivery slot and the excellently packed eyepiece duly arrived today. The condition described is accurate and I’m fully satisfied.

I’ve bought previously from ENS by post and also in person when they’ve been at Kelling star party. When buying by post we have to rely on an honest description plus prompt secure packing and shipping. I’ve found ENS to be exemplary in this regard and it’s worth paying a bit more for trusted service in my opinion. Recommended.

Ed.

2 hours ago, Surfer Chris said:

I’ve sorted the undercut problem with hard plastic tape. Dymo tape for label making is ideal. On the eyepieces I’ve used that on the undercut was just a fraction deeper than the tape. This worked fine, no snagging job done. Regular electricians tape is too soft.

Ed.

This problem is worrying on otherwise great eyepieces. I’m a fan of the discontinued TeleVue Radians. The clickstop eyeguard was often criticised for being too loose, but easily fixed by dismantling and reducing the diameter of the internal spring.

It’s a mystery to me why TV have persisted with sliding eyeguards. A well engineered screw operated eyeguard is the simple solution. Pentax XW and XL are good examples of this.

Good that the Delite problem can be sorted with end caps that fit a bit looser.

Ed.

I don’t think you’re being paranoid just legitimately sensible. There’s no guarantees but some things you could do-

I’m one of 4 keyholders who arrange visits to my club’s dark site. We are able to lock a gate on the single track access road. If you could do that it helps prevent unwanted vehicles turning up.

We don’t go there on our own, always with an observing friend (or friends).

Obviously have a charged phone, even if that won’t bring immediate assistance.

If unwanted folks do pass by if you keep quiet they may not be aware of your presence in the darkness. My scopes are hand driven so no motors buzzing.

If you’re hidden or partially hidden by bushes etc that will help.

If you are spotted keep calm and as friendly as possible. The unwanted visitors may well not be looking for trouble. Calmly explain what you’re doing in a friendly tone and you may find they leave you alone. If they’ve ruined your dark adaptation with lights it probably won’t be deliberate so just accept it.

All the best for safe enjoyable nighttime sessions, Ed.

You mention the mount works fine but has cosmetic issues. FWIW, here’s what I would do-

If it’s working ok I wouldn’t strip it down. I’d remove the peeling chrome as best I could, rub down with fine emery paper, treat with Kurust or similar, repaint with silver paint. Done carefully it should look fine. Of course the bent bits will need straightening, a good solid vice with padded jaws and a bit of grunt should sort it. Some steel tubing would give more leverage.

As for the tripod, if the legs are rubbish I’d make new wooden ones fitted to the original tripod head. I’m guessing the tripod head should be ok. An alternative could be a Skywatcher steel tripod, these come up second hand sometimes. You may find something at ENS Birmingham, top prices but I’ve found the descriptions are honest and a reliable service. I’ve adapted several tripods to fit various mounts, with a bit of thought and a basic workshop there’s usually a way that works.

A nice summer project, have fun 👍 Ed.

3 minutes ago, Pixies said:

Ah ha! perhaps it's the difference in temperature, but now the dew shield comes off very easily, leaving the (non-collimatable) lens cell behind. That wasn't happening yesterday:

Great you had success 👍. Further pic below of the collimateable cell on my very early version.

14 hours ago, Pixies said:

One quick question for starters - for anyone who has/had one: I tried to remove the dew-shield but it only appears to unscrew. However, I can see that the lens cell appears to rotate with it, so I'm a little worried I will end up removing that too. Can the dew-shield be removed without loosening the lens cell?

Great classic scope👍  On my Vixen 80m the dew shield simply pulls off the lens cell.  However mine is one of the very early versions. The pics below show the earlier label and the collimatable lens cell.  Having pulled off the dew shield the lens cell unscrews as a unit from the tube, this does not disturb the 2 lens elements.  Be careful when screwing the cell on, the threads are very fine.

You’ll find that Delta Cygni is a tough call with this scope, but very steady conditions with Delta Cygni high overhead can bring success.  Don’t be afraid to ramp up the magnification !   If you need to know more please ask.

Ed.