RobertI

Thanks John, I’ve never seen a concentre before, it does look like an improvement over a Cheshire. A laser collimator is on my list. I had thought about upgraded mirrors if mine turned out to be dodgy - did you find them easy to fit?

Thanks John, had a quick skim of the article, and although it's similar to what I had seen elsewhere the diagrams do raise some questions about collimation. I'm pretty sure I was well collimated - firstly with a cheshire indoors and then with a defocused star on the night. I didn't notice any assymetry, but accept this can be complex. What confuses me is how it could resolve close binaries after a poor star test?

Thanks Stu. I'm really looking forward to getting more into the world of double star observing! I've posted more about the star test problem here.

I had a great first light with my new 150PL last night - full observing report can be found here . In summary it fulfilled my hope as excellent double star splitter, clearly splitting a test pair of 1.5" separation and fleetingly splitting a pair of 1.0" separation in moments of clarity. The focuser was on the stiff side, making it hard to not wobble the scope at high mags - I may invest in £45 Skywatcher motorised focuser which many other folk seem to have done. However, despite the excellent double splitting ability, the star test results were awful. Now I am no expert, but the extra focal image seemed sharp and more or less what you would expect, but the intra-focal image was just a fuzzy mush! I have done a very poor drawing below from memory (not sure if they'll confuse more than clarify) - extra-focal on left and intra-focal on right. If I understand the results correctly, it shows the mirror is overcorrected and possibly suffering from a turned down edge (depending on what you read). Assume the circles in the drawing are concentric and even!! Also the in focus star didn't show the diffraction pattern I was expecting. Instead of one bright diffraction ring and possibly a fainter one, I could see several very fine and closely spaced rings of equal brightness - I don't think this was an illusion, but it was faint. Aplogies for the naff illustration again, what I was expecting is on the right, what I saw was on the left. The airy disc seemd ok and well defined and the focus, whilst not 'snapping' seemd easy enough to find. I have read that mirrors can become overcorrected as the temperature drops, but seems a bit unlikely as the scope was well cooled. Can anyone explain what on earth is going on??

Had a great session and first light last night with my new (previously loved) 150PL. I purchased this scope specifically for observing doubles, so I was very interested to see how it would get on. Having introduced it to my venerable Skytee 2, I ventured forth. I started with the crescent moon and Venus which looked gorgeous in the darkening azure sky. At a low power the dark maria were plainly visible in the darkness of the earthshine and the illuminated crescent was showing some lovely features, including Mare Crisium and Cleomedes nearby by with an interesting scattering of small craters on the flat crater floor. Venus was showing a nice gibbous shape but, oh my, I forgot about the diffraction spikes you get with newts!! Into the back garden and out of the wind to do some deep sky stuff, having let the scope cool for at least an hour. Starting with a quick star test on Polaris the image was dancing all over the place - clearly not a good night for tackling my pre-prepared list of doubles. Polaris's companion was easily visible, and slewing over to Alnitak, its companion was also clearly visible in the glare at 240x - a promising start as it has proved to be tricky on nights of poor seeing. Next was M42 - at low power it was, as always, stunning, with the wings curving a great distance into the darkness and the trapezium beautifully resoved with tight stars. Higher magnifications showed the trapezium floating in the mottled pattern of the box shaped core, with an inky black hole nearby. A short interlude followed for dinner and to thaw frozen hands and numb toes. When I returned the seeing seemed to be much better, so I thought I'd have a go at the E and F components. At 150x I couldn't see anything apart from the fours stars. Cranking up to 196x I could immediately see a very faint fifth member, but no sixth. But I persevered and eventually I could make out a sixth member, flitting in and out of view, but 100% there. I honestly didn't know where the E and F should be located beforehand and checking my results on-line confirmed the catch. This is the first time I have caught the F component in any of my scopes, so to say I was chuffed is an understatement - a great result for the 150PL! A quick look at the Eskimo nebula - very obvious with a star like core and extensive fuzzy shell. Then, flushed with the success of the Trapezium, I thought I would try a couple of more challenging well placed doubles. First was 57 Cancri, with its two mag 5 and 6 components separated by 1.5" - once found, this was a clear split at 196x, which made it closer than anything I have ever split in the C8 or the 100RS. Very pleased. Apologies for the drawing which does not show any field stars - my hands were really cold! Nearby was STF1338 in Lynx, a closer double with its mag 6 and 7 components split by just 1.0". I didn't really expect to be able to split them, so I cranked up the magnification to 240x and to my amazement, I found that in moments of stillness, the split was evident. Most of the time it was a clear elongation of the pair, but in those brief moments, a black line appeared between the two. Checking my estimated position angle confirmed I was not imagining it. Oddly the position angle and magnification difference of both pairs was almost identical and I had to check I was not looking at the same pair again! I did feel that the scope and conditions would allow more magnification, but I didn't have the equipment, so a new eyepiece or barlow is next on my list. Overall I'm extremely happy with the scope. It's double splitting ability lived up to my expectations and despite it's relative bulk, it was a joy to use - somehow the eyepiece always seemed to be at the right height and in the right place! However there were some niggles, and the star test which I performed under the improved conditions later in the evening, was, to be honest horrible! I'll post more information in a review of the scope, and hopefully get some opinions of more experienced members. But I guess the proof of the mirror is in the splitting, and it was pretty darned good at that tonight. Clear skies.

What an array of exciting products and knowledgable providers - hope you have a great show. 👍

Remarkable.

Really nice animation, well done.

Even better! 👍

That’s something to look forward to, I’ll start planning for it!

I’ve just ‘rewound’ Sky Safari to 40 years ago to see what the sky was like when I first got into astronomy as a 14 year old. I didn’t realise how lucky I was! Jupiter, Saturn and Mars close together and high in the sky. Must have looked amazing.

I have just been out and measured the tripod height (as set for viewing with the 150PL when standing) and amazingly it is almost exactly the same height as the pillar (90 cms), so the pillar would definitely work for me. I can't honestly see myself buying one of these at the moment though, unless there is a perfect storm of me loving the scope, hating the tripod interference, and a cheap pillar being advertised locally!

Thanks Stu, I have been thinking about that, but I thought it might raise the eyepiece height beyond the perfect position it seems to be for observing when standing - I don’t think the tripod legs will go much lower, 6” of travel left at most. I could break out the platform shoes I guess 😄 A pedestal would work but not very easy to move and store. I guess I’ll have to see how it goes......

Genius!

The new scope has arrived.... I have to say it’s a lovely bit of kit. Only a slight dink in the tube but otherwise flawless. Collimation was way off, but as @Lockie told me, it actually was easy to collimate. I set it up on the Skytee 2 and, with the tripod legs mostly collapsed, the eyepiece is at the perfect height, with the slow motion controls (the azimuth with a cable and the altitude with a knob) easily to hand without any stretching - seems very promising from a comfort point of view. The tube does hit the tripod legs (I’ve put padding on the legs to prevent damage to the ota) - I don’t know how annoying this is going to be, I’m expecting to work around it by just picking up the whole thing and moving round to the right areas of sky, this will also ensure the slo mo controls are always in the right position and easily to hand for high power viewing (I bought the scope specifically for doubles). I replaced the 6x30 finder with my Altair Astro 60mm finder to help finding those fainter doubles - this may end up being overkill. My only criticism is the focuser is quite stiff, but is nice and smooth - I can’t complain after the helical focuser of the Heritage 130P! I’ve yet to have first light with it, but I’m planning on posting my experiences with the scope over the next few months in this thread.

It’s clearly a device for attaching one end of the rail to a female thread with a force that will stop it rotating and attaching something to the other end of the rail for some obscure and devious purpose. I simply can’t imagine what though!

I have a couple of Webb Society Deep Sky Observers Handbooks, bought in 1980 and well used. Not had much involvement with the Society, but I really should have, thanks for the reminder, I shall go and investigate the website now!

Just bought this lovely 150PL newt from a very nice gentleman in Stratford for £90. We did the exchange in a pub car park and I was worried that passers by might think it was an illicit arms deal involving a bazooka! Anyway, really looking forward to eyeballing some doubles with this beauty. 🙂

Sounds great, Id love to have a peek through a large pair of bins like yours.

Lovely set of captures, some fine detail and colour coming through. What s/w did you use for live viewing? Is the Evo mount the Celestron one that normally comes with SCTs? (I can’t see your sig on my mobile phone!)

Nice sketches, your M42 looks nicer and more accurate than my recent attempt, which I am still debating posting! 🙂

An amazing night by the sound of it, some objects I would love to see (but would struggle with my LP and 5” of aperture!). 👍

Great report, nicely described.

Nice observation John, interesting effect, I shall look into Hb filters a bit more and educate myself. I was out observing M42 last night with a special NRH filter (Neighbour’s Roof Heat) which removes ALL interesting detail from the object. 🙂 I’ll post a report later.

Nice captures, NGC1501 is a tricky one, you've picked up some nice ghostly green there.