Captain Scarlet

Even at f/2.8 you may well still need to go beyond, say, 15 second exposures which is more or less the limit before you get noticeable star-trailing.

By which I mean to say you may want to consider some form of tracking, if you don't already, such as a SW Star-Adventurer. I use an AstroTrac. My default option for MW shots is to shoot it with 40-second exposures using my Samyang 24mm f/1.4 at ISO 1600 on a Canon 6D, though I am at a very dark site. 3 of those 40-second subs using just that set-up, stacked and stretched gets you this, which some may consider overdone but I like it:

4 minutes ago, markse68 said:

That’s how I do it too- read about something on here or other forums and add it to the ever growing list

hear hear

Superb, quite jealous. I love the pic with Venus and the Pleiades, and, if I'm not mistaken, Mercury? just below the slow-mo extension. Enjoy the coffees!

Magnus

I have had exactly this problem with my AZ-EQ6. See my pic below. It mystifies me why they'd allow a design of this sort without the ability to align two scopes: otherwise what's the point? As you say, in alt it's fine you have adjustments, but in az not so. I started off by shimming, but it was risky: I was all too aware that a bad fitment would send a scope crashing to the floor! So I got this:

https://www.baader-planetarium.com/en/baader-stronghold-tangent-assembly.html

... which works fine, but does flex a tiny bit and needs small adjustment at different angles for different altitudes when I inevitably overload it (that's a 300p and APM/LZOS 105!). But even with the flex it is immeasurably better than with just the supplied dual saddle.

Cheers, Magnus

I was defeated by cloud around 2am having only got Saturn Jupiter Neptune and Mars. But the comet at that time was spectacular, it had a tail that I measured as 10 degrees long! Same distance as between Megrez and Merak.

1 hour ago, JOC said:

I tried tonight.  The only bank of cloud for 10 miles was sitting in a line just across the whole North/Northwest view and between that and the expected bank of leylandii there wasn't a proverbial chance of seeing the sky let alone a specific comet 😞

So annoying! sorry to hear, I know that cloud bank feeling. I’ve just managed to get a whole family hanging out of their top window with bins seeing it for first time. I seriously hope you see it in the next day or three!

M

Double-sided number plate tape works well too. I think I got mine from Halfords.

M

I was out briefly last night, Wednesday 15th, because it was clear, and managed to find the Comet again. Higher than Friday/Saturday obviously, but much much dimmer, by 1.5 magnitudes. I was able finally to get it through 10x50s when zenith darkness was around mag 16.5, and it became naked eye at mag 18.6 . `not worthy of dragging people out of bed but lovely nonetheless.

M

1 hour ago, Pixies said:

... One interesting thing she mentioned is that when you are trying to measure it yourself, if you eye is trying to focus on something close, like a mirror, this will cause your pupils to contract. Worth bearing in mind, depending on how you are doing it.

seriously though, because the light from a star is parallel, I would think the allen key method should also work with the allen key held a distance in front of your face, avoiding forcing you to squint?

I'm definitely going to try it

On 14/07/2020 at 11:17, AstroMuni said:

Taken from Astronomy Hacks book by Robert Bruce Thompson; Barbara Fritchman Thompson.

Your eye doctor can measure your fully dark-adapted entrance pupil for you, but you can also determine it for yourself. To do so, you’ll need a set of metric Allen wrenches. Allow yourself to become fully dark adapted, which may take half an hour or more. Look directly at a bright star, and hold one of the smaller metric Allen wrenches along your cheek so that the long portion crosses your eye parallel to and near the eyeball.

Move the wrench up and down until it is centered on your pupil. You’ll see the star split into two stars, one on each side of the wrench. Substitute larger Allen wrenches until you reach a point where the star no longer splits, but is visible only as a single star on one side or the other of the Allen wrench. The size of that Allen wrench is the size of your fully dark-adapted entrance pupil.

If you observe frequently from a light-polluted site, repeat the experiment there. You may be surprised at the difference light pollution, particularly from nearby local sources, makes to your dark adaptation. For example, if your entrance pupil is a full 7mm at a truly dark site, it may be only 5mm at a brighter site. Your eyes operate on the same principles as any optical instrument. Light gathering ability varies with the square of the aperture. That means a 7mm entrance pupil admits nearly twice as much light (7² versus 5²) as a 5mm entrance pupil, which in turn means that you can see nearly one full magnitude deeper from the darker site.

Unfortunately that method only works in Europe, and in the UK for now but for only a limited amount of time. In the US and shortly in the UK it'll only work using Imperial allen keys  

M

Christ! How NOT to take apart a mak of that design. I wonder how many have done what he's done and seriously damaged their mirrors as a result. He's basically pulled out the inner baffle tube from the outer, on which the primary sits, leaving the primary to hang off the focus rod inside. As soon as he takes off the focus-knob assembly, the primary collapses on to the corrector plate. I think there's a similar one with the mak 150 where the primary gets chipped in the process.

5-6 full turns on the focus knob is huge. I'd expect backlash as such to be of the order of a quarter turn. It sounds to me as if the threaded rod which the focus-knob pulls up and down is not properly fixed at its other end to the buttress-plate behind the primary mirror. If that's the case, it may be the rod will become separated from it in due course, in which case the threaded rod will be flopping around inside the tube and potentially spreading the evil black grease with which it's covered. I'd definitely send it back I'm afraid.

For an idea of what's going on behind the focus-knob, take a look at this thread, which although about my Skymax 180, is more or less the same focus design. But as John said, definitely do not take it apart, you may well invalidate any warranty.

22 minutes ago, endlessky said:

Fantastic report! It's always nice when things go completely right, as they should, on some things like these. Unfortunately, spectacular comets like this one, and Hale-Bopp, the first one I have ever seen, feel too often like a "once in a lifetime opportunity", so when things DO go wrong, you feel like you missed out and inevitably wonder "will I ever get another chance?". I have a lot of beautiful - film - pictures of Hale-Bopp, and most of all, a great feel of wonder and magnificence etched in my memory, something that I am sure will stay with me throughout my lifetime, but not much to show regarding Neowise. I did wake up at 3 am a few days ago, when I finally had a clear morning, but things in the setup didn't quite work as planned and only manage to take a few shots between 4:15 and 4:30, when it was - sadly - starting to get too clear.

So, I look at your - and other people's - experience with joy that everything worked out good, and - yes - even with a little bit of (friendly) envy.

Thanks: I was very lucky to have had a dodgy night the previous one, to get the gremlins out of the way. I've always been passively interested in astronomy, so am puzzled as to why I never got to see Hale-Bopp or Halley's when they were around. I did, for instance, take a day off to drive down to Falmouth to see the August 1998 solar eclipse

25 minutes ago, RobertI said:

Lovely report and pic, the comet sounds amazing, yet to see it myself. 😕 For the tiny planetary nebulae, you could try ‘blinking’ an OIII filter across the front of the eyepiece, the stars are dimmed but the PN stays the same. I’ve only just got my OIII filter so not tried it myself yet, but understand it works well. 👍

Thanks Rob, I hadn't thought of doing that with a filter, very good trick. I'll try it next time. Hopefully you'll get to see the comet, fingers crossed for just one clear night in the next week or so: shouldn't be too much to ask in July!

Last weekend was looking good to being my first opportunity to observe in nearly a month! Thursday and Friday nights were forecast clear, and luckily I’d got Friday off work too, so a late Thursday wouldn’t be too painful.

For Thursday the Moon wasn’t due to rise until around 1am, and I’d made a list including several nebulous objects hopefully viewable before the rise of the 77% Moon. I also had a raft of Globulars. And Comet Neowise of course. And the Planets. I set up with my Southerly view, in the clearing around the back of the house to get the planets, and my list was mostly orientated accordingly.

I was also planning to use my Nexus DSC instead of the SynScan to directly control my AZ-EQ6 mount.

Night 1: Thursday 9th July. Controller Frustration, Bad Seeing, Dew and Cloud: Lessons Learned.

In the event, the night, although disappointing from an observing respect, proved a useful set of rehearsals for the following much better night. The night was clear and dark enough, good enough for a decent photo of my scope with the MW in the background (forgive the Samsung-24-1.4-inherent coma on Jupiter!):

It'd been a month or so since I’d had my first go with the Nexus DSC/AZ-EQ6 combination, and I’d basically forgotten how to use it, especially Alignment. I wasted more than an hour trying to crack Alignment and eventually gave up, reverting to the SynScan instead. I had been planning to re-read the manual during the day, but hadn’t got around to it. More fool me.

Once aligned using the SynScan instead, I of course first pointed to Jupiter. Oh dear. The seeing that low down was TERRIBLE! Barely-discernible main bands, and nothing else except atmospheric CA. But it was an impressively huge object at 150x with my Delos 10mm. I did get to see a transit/occultation of one of the Moons however, just a tiny white dot “off the edge” gradually merging and disappearing. There was also at least one maybe two background stars masquerading as a extra Moons, at very similar brightness and nearly in line with the rest. Saturn was similarly wobbly and detail-free, but also much bigger than I'd seen before. I am so looking forward to 2-3 years’ time when they're high up. I’ve never observed them properly yet.

My next intended was Antares, to see if my 12” of resolution could see any sign of its double. Not a chance. Antares was a reddish wavy huge moving splodge. So spread out by seeing that it was even greater in extent than Mars' disc was later in the evening.

After that poor start, I moved to my list of PNs. Universally disappointing, I think they were all dew-affected. I found NGC 6781 “Ghost of Moon” but it was barely discernible, just a faint patch. I looked for NGC 6309 “Rectangle” but failed to find or notice it. In hindsight I think it was because it’s extremely small and I may well have mistaken it for a star, given the seeing. NGC 6894, one of a few so-called “Diamond Rings” similarly eluded me.

I skipped the Veil, leaving that until I could bring my Oiii filter to bear. I’ve actually not yet seen the Veil in any form. The Eagle Nebula was also I think too big and spread out for my 0.48 degrees of view, but I did find M27 Dumbell easily enough.

However by now everything, including optical surfaces, were getting seriously covered in dew and I had no mitigation. And clouds were heading across from the North: they’d been there all along and had made sure there was no chance of seeing Comet Neowise that night. And the Moon was about to rise. I finished off with a quick look at Mars and that was it.

That hour lost to Alignment problems proved expensive in Units of Viewing Time. But a useful preparation for the following night, as it turned out.

Night 2: Friday 10th July 2020. Nexus Conquered. Dew Conquered. No Clouds. My God the Comet!

I learned the lessons of the previous night, and during the day I re-read the Nexus DSC manual. I found out where I’d been going wrong, and this night I managed to master Alignment. So much so that when I had a power-off blip mid-observing later on, causing tracking and position to be lost, it took me all of 2 minutes to reset the scope’s position and do a 2-star align and get back on with it. I was also enormously helped by the fact I was finally able to use my year-old Telrad for the very first time, thanks to the 4” Telrad riser I bought from @johninderby (thanks). Beforehand I’d found the Telrad impossible to use, needing to get my cheek right down on to the tube, uncomfortable.

Another lesson I took on board was ALWAYS HAVE THE HAIRDRYER ON HAND. I used it several times during the evening. I enjoy how it briefly totally destroys the seeing with a tube full of hot air, then rapidly clears up.

I used the same list as prior evening, hoping to get better results, and so they mostly were. On top of that, this night was truly pristine, not a single cloud anywhere from horizon to horizon, except for my first-ever-seen noctilucent clouds to the North norizon, which only made Neowise more beautiful.

I had a quick look at the planets to start with again, better than last night, but still spoiled by atmosphere. I didn’t bother with Antares. My first nebulous target was again the Rectangle Nebula, and again I didn’t find it. Has anybody here seen it? Is 150x too low a magnification for something like that? Darkness level was around 21.10 so should have been no trouble?

I skipped straight to M17, found it straight away and gasped. I was looking at a very distinct swan shape, clear as day night anything. Sure enough, M17 is known as the Swan Nebula. Remarkable.

Next was M20, Trifid Nebula ,and I was confused that once again I couldn’t see or find anything except what was obviously an open cluster. On reflection, it’s obviously too big and nebulous for the 150x magnification I was using. I moved a little to M8, Lagoon Nebula, and was greeted with much nebulosity and a highly distinct dark channel. Much like a huge burger. But once again, I think my mag was too high. I seemed reluctant to use anything other than my Delos 10mm though.

Finally, I rattled through a series of Globs, there are so many in that region. I looked at Messiers 10, 12, 14, 22 and 4. I find Globs mesmerising and entrancing.

The Comet.

In the midst of all that, though, when it had got as close to as dark as it was likely to get - I measured 21.10 around 0015 - I turned my attention to Comet Neowise. I’d been eyeing it naked-eye of course throughout the night, and it just got brighter and brighter and the tail longer and longer. I put in my Panoptic 35mm to the 12” (43x) and the view was beautiful. I took a few rubbish shots hand-holding my phone to the eyepiece. But whether naked eye, binoculars or through the scope, it was truly memorable.

In my excitement, and wanting to share the almost transcendental experience, I instinctively called my near neighbour across the field intending to say “you need to see this”. The call wasn’t answered. I tried again, again to no answer. Only then did it occur to me to check what time it was: it felt like early eveing to me. No, it was after midnight, no bloody wonder there was no answer! I cringed, hoping they’d had their phones on silent.

In fact what happened at the other end was, apparently, this: “Who the bloody hell is that at this time of night?” “Er …. oh, it’s Magnus.” “You know what, I bet it’s the comet.” So they got out of bed to have a look, to see this:

On seeing that (and I carefully processed the image to show it exactly as it appeared naked eye) my neighbours immediately rousted out their two teenage daughters as well. I was completely ignorant of all this, still cringing at my faux-pas, so I was hugely gratified and relieved to get a text 10 minutes later saying “That is totally cool!! We’ve all had a look and are expecting fantastic pictures!”. Awash with relief, it was that that prompted me to get my proper camera out and take the above image.

Jason, the man-about-the-house, said afterwards “D’you know I think that was the most beautiful thing I’ve ever seen. Yes there was a moment of initial annoyance at the phone, but we’re just so grateful you woke us up”.

Because I’d set up my rig behind the house, taking 20-30 minutes and perhaps 10 trips to get all my stuff back inside, I had to walk past and look at that view in passing many separate times, and it’s now etched into my memory.

All in all an observing night I won’t ever forget. The Nexus DSC is a lovely little unit, and even not yet being remotely familiar with it I vastly prefer it to the SynScan, for many reasons. But I think I’m going to have to start a new thread solely about that. For example, after first use I had some questions about how it worked specifically on the SW AZ-EQ mounts, so I emailed Astro Devices. One morning later Serge from Astro Devices called me and sorted me out. But I think it needs a separate manual devoted to its use on driven mounts only: I might unofficially write it.

Cheers, Magnus

Quite incredible image. Very much the best by a distance I've seen. Thanks.

M

I've only been into this pastime for 3 years or so, but I still fully get that wow moment every time I look at Jupiter and Saturn. And they're not even close to full crispness yet being so low down to the horizon from the UK.

M

Buddleia very good. Smells fantastic, very attractive. Insects, especially butterflies love it and it grows extremely fast. And it doesn't mind a brutal prune from time to time as and when necessary.

... don't forget the TV DeLite 18.2, by all accounts a match for the Delos 17.3. I have 3 Delos: 6, 10 and 3.5 so am aware of their quality. However on agiven night the DeLite 18.2 is generally the first eyepiece I put into the slot, I really like it.

M

... btw image best viewed in a dim/dark room for best effect, to reflect how it all appeared to night-adjusted eyes. And on closer inspection those clouds below it unless im

mustaken, quite possible, are noctilucent, never directly seen them before actually.

M

So many great pics of this. My own contribution below. This is pretty much as it appeared naked eye all night: I was out with my 12" newt and observing other stuff too. It was mesmerizing, the whole scene had a portentous feel to it. I will have to edit that annoying power line out at some stage though.

Canon EOS6D Samyang 24mm f/1.4: 4s f/1.4 ISO 1600

Cheers, Magnus

Stunning. Just spent 45 minutes packing away my 12” and paraphernalia about 10 trips round the house in all. Every time I had to pause to look at the cometary vista 

I did get up, and sat watching clouds scuttle across from 0330 to 4 with no gap. Wrecked now. Oh well at least it'll be more convenient albeit dimmer at more usual observing hours later this month:

7 minutes ago, niallk said:

So cool - dyin to see it!

yes me too. ready and waiting, even with a tripod and camera, for the forecast clouds at 0330...

58 minutes ago, andrew s said:

 

Enjoy your (whatever the collective noun is for telescopes is) of telescopes.

I believe the collective noun is “divorce”