cwis

I am hugely tempted to get the screwdriver out and see what kind of adjustment I have available - it's not like I could make it much worse at the end of the day. I'd love to know whether there are springs or squidgy foam or something under those clips. I'll wait for a reply from Auntie Flo first though - there may be a "procedure".

That's an amazing piece of work there - basically a different 'scope! Do the optics warrant that sort of attention or are all optics pretty good nowadays (at the entry level) and it's the engineering of the rest of the 'scope that makes up each price point? I notice that it was perfectly collimated before you took it apart. Did you expect it to be or was this a pleasant surprise?

For completeness, here's what it looks like with the secondary mirror concentric to the focusser: If anyone can suggest how I get the doughnut and the c-cap to line up without using primary mirror adjusters, please pipe up now!

Haha! I thought you'd remember eventually! Never mind - you've taught me how to collimate a Newtonian telescope! Many thanks! I was expecting that when I got the primary concentric on the secondary, then the doughnut would be there or thereabouts so a few tweaks and I'd be home. It looks like it's quite a way out (a good proportion of the secondary mirror's diameter) and I'd need to offset the secondary perpendicular to the primary to pick up the centre of focus - an adjustment it obviously doesn't have. Or put up with a tilted focal plane and an offset sharp spot (what I have currently). I'll contact FLO in the morning unless anyone else chimes in with any other thoughts. It could be the one that slipped though the net from the factory, or it had a right wallop during dispatch. The finish is flawless though, and the box didn't look particularly sorry for itself when it turned up, so I don't know.

It makes loads of sense and thanks to you and these last few messages I feel I completely understand collimation. Just one issue: I have no primary screws! Would you agree that it looks like the primary is out of collimation? That's the conclusion I am reluctantly coming to.

But that's my point: I can get the outside of the primary concentric with the secondary, OR I can get the doughnut lined up with the centre of the c-cap. I can't do both at the same time. If I could adjust the primary, I'd get the clips concentric as you say, and then work on the primary mirror to line up my doughnut. But I have no primary adjustment.

Hi all, I've done a little more investigation.... I attempted collimation from first principles - using the Astro-baby guide in so far as it applies to my 'scope. I'm still scratching my head. Initially I wound the focusser down as far as it would go to close up the gap round the secondary mirror so I could centre the mirror as closely to it as I could. I put a folded plastic bag (green and white) behind the secondary, and a white bent card in between the secondary and the primary. Then I adjusted the centre screw in the secondary until it looked in the middle of the view down the focus tube (through the collimation cap) So here I am with the secondary mirror as centered as I can make it - looks like it's rotated a bit up in this photo (along the horizontal plane) Next I rotated it to get it as circular as possible - turning it around the central screw. Then, fine adjustment with the tilt adjusters on the secondary to line up my doughnut on the primary with the c-cap, with my pupil - all in a line. So - doing this I encounter a problem, or question, or something that someone can point at and go "Nope, do it like this". I've done this a few times now, and whether I have the secondary "too far out" or "too far in" so to the left or the right of the centre of the focus tube (and then line up the primary) or rotate it up, or down (and then line up the primary) it always lines up with the view like the photo, with the edge of the primary vanishing off the side of the secondary. It doesn't matter where the focusser tube is - I can't detect any tilt in that until it's nearly all the way out, but obviously the more I wind it out, the more primary mirror vanishes. This is a photo though the c-cap by the way, so central as I could make it. What am I doing wrong? My sharp spot, coincidentally, was at 45 degrees to the left of the view which lines up with this too so I'm pretty sure whatever I am doing here is the cause of that issue.

Hi Steve, thanks for the reply! What I will do is more investigation on the next clear night and find out exactly what is wrong. If I still think there's an issue with the scope I'll contact you as requested. As you (very tactfully!) didn't say, the odds are it's my inexperience in something I am doing with secondary mirror alignment or similar showing rather than any issue with the scope - I totally accept that. I've asked the good people of this forum for assistance on what I saw as a collimation issue and they have given me some pointers on how to be clear what exactly the issue (if any!) could be - I'll follow their guidance to a conclusion. If we can get the sharp spot in the centre of the view (and therefore it will probably a lot bigger because it will be parallel to the focal plane) I will be very very happy with the performance of this scope. I thought it was "OK" before but the views of Mars the other night were, frankly amazing - I had no idea it could do that. Brilliant for a scope I effectively got "free" with the Az-gti and tripod!

Will do - don't want to upset Auntie Flo! I'll find out next clear night as to whether it's astigmatism. I do have an artificial star flashlight thingy, but to focus on it at the end of my garden the focusing tube will be in a hugely different position to how I use the scope it's not worth doing tests with, if we suspect the focuser.

All good questions. I'll see next clear night. As I recall when I received the telescope it looked like the secondary mirror had rotated. While pondering the seagull shaped stars under higher magnification during the day, I looked down the focusser and could see the mirror quite clearly was pointing in a direction!

Good question! Box was fine though... I'll do more investigation next time it's clear. It was near the end of my session on Mars that I had the thought of doing a star test, so time was fairly short. Mars appears round the side of my shed above lovely cool woodland for an hour or two before hiding behind next door's house. I found the sharp bit and started waving it at Mars straight away.

Cripes. Glad you said that before my Dob turned up...

So does flocking a scope void the warranty? You normally take the mirror cell out for that....

Yup - FLO!

Interesting! I wonder how they could tell you attempted this...

I'm wondering whether it already is? Maybe during manufacture? Surely processes aren't so precise that they can throw them together without checking and assume they are collimated?

Hmmm. Issue there is everyone is out of stock of everything at the moment. Currently I have a telescope - it's a wonky one by the sound of it, but at lower powers of magnification seems fine. If I sent it back I'd just have my eyeballs currently. I've got a Dob on the way but who knows when it will turn up. I'm completely prepared to look sideways at Mars for the next month or so! When this scope turned up the secondary was WAY out - seagull shapes in the 10mm eyepiece. It's loads better now but obviously not perfect. It's been good enough to get me totally hooked on the night sky though! The focusser is quite stiff and has a fair bit of slop in it - I think I need to do some more investigation - it could be the culprit? My "sharp bit" was directly above the centre of the view. Is that really a coincidence? If my focusser "droops" would that move the sharp spot up in my field of view (as well as tilting the focal plane and all sorts of other stuff)? I'm finding it hard to visualise... Next clear night I think I'll star test on stars at different inclinations and see if the sharp bit moves about.

Hello! Yes it does. When looking through my collimation cap I see my three mirror clips, a centered secondary mirror, the reflection of the back of the cap in the main mirror and the reflection of my pupil as close to the middle of the doughnut as I can make out.

Synta ARE naughty scamps! I can adjust the secondary, yes - maybe I need a cheshire then - I've got a Dob on order so it won't be wasted. Hopefully it arrives before the heat death of the Universe.... I adjusted the secondary using my c-cap as best I could. I guess that's not precise enough? I have to say though - when I got Mars in the sharp spot last night I was amazed. The optics are VERY good. All I need to do is get that spot in the middle!

Hi all, I was looking at Mars last night and I thought I'd have a go at a star test of collimation - never done one before. I was led to do this because although the seeing looked pretty good I was still low on contrast and had better views (more contrast, sharper) with most of the aperture of the telescope obscured by its cap - with just the small hole in the cap uncovered. The planet seemed a bit fuzzy edged, indistinct. I could see the polar ice cap, but as a blurred splodge. So far I've not been thrilled with the planetary views from this scope - I can just make out the GRS and just about make out the Cassini Division (I think) but as this is my first season of observing I thought it was just sky conditions as the planets have always been low. But Mars was pretty high in the sky last night so doubt crept in. I pointed at Polaris... I've badly drawn what I saw just inside focus... So the first image is the diffraction pattern looking at Polaris when centered in the view - it told me collimation was a bit out . Hey ho - I can improvise: I moved the pattern around the view until the pattern was concentric - I ended up near the top of the view as on the second image. I remembered this position and pointed at Mars, and put the planet in the "sharp spot". My word! Proper sharp edged planet with occasional glimpses of razor sharp detail on it's surface, the edges of the ice cap sharply defined, as sky conditions allowed - amazing! So - the questions! Why is my pattern oval (I've exaggerated it a little). I expected a round one? Interesting that it is in line with gravity - is it the focusser bending? How do I get my sharp bit in the middle? I have the Skywatcher Explorer 130ps - the main mirror is not adjustable. Using a collimation cap the secondary looks to be centered on the main - do I need to be more precise in this or is that the limit of adjustment for this scope? Or is the focusser bending when I fit an eyepiece? I've seen the occasional 650mm collimatable mirror cell pop up on Astroboot that looks a direct replacement for my non-collimatable one (assuming from a Heritage 130 et al) - should I fit one of those? Am I just being too picky for an entry level scope? I was using a Nirvana 4mm eyepiece by the way so 162x - not excessive?

Back in April I was in your position. Ended up with a 130mm F5 Newt on a goto Alt-Az mount. Absolutely love it, it's out every clear night, it's teaching me to find my way around the night sky, etc etc. I ordered a 10 inch Dob about a month ago. So the 5 inch newt lasted me around 4 months before I wanted more. More resolution for solar system objects - I can see the Cassini Division and the GRS - just about, but I want more. I could get better contrast and maybe slightly better resolution than my Newt with a reasonably priced Mak, but then that's not much use for DSO (no offence Makkists!) and that's an issue because... I also want DSO! Fleeting glimpses of M3 (tiny dim smudge) and the Ring nebula (very very faint weeny smoke ring) have whetted my appetite. And the Dob will get me both closer to Mars and deliver brighter bigger DSO in one package. That you have to nudge.

It did very well - I'm really pleased. Thank you for the recommendation! I'm glad I did my research first though - it was never going to be sharp right to the edge. Rolling round the sky last night really started making me think about a big dobsonian. A nice lightbucket to pick out those M numbers. People always say buy a dob as a first scope, but I don't know whether I'd have got as much use out of one as I have with my Alt-az. Now, armed with a little knowledge however....

Right! FINALLY got to pass some photons through the Altair last night! I had a variety of targets last night, and a new way to navigate between them (picture attached). Inside the quickly printed hot glued exterior is an ESP32 and an analog joystick. The ESP32 was flashed to use Micropython just because - I usually use the Arduino dev environment with them. I threw together a script that looked for a SynScan* wireless network and connected to it, and then looked for a host listening on TCP port 11882 and connected to it. One joystick enabled Az-Gti mount! After aligning the mount (Polaris and Merak) I popped over to Epsilon Lyrae to see how the seeing was with a 4mm EP - it wasn't as good as expected - I could split the vertical double, but not the horizontal one. Then moved to Albireo and compared the Altair to the standard SW 25mm MA that came with my telescope, plus my Seben zoom on 24mm. Conclusion: The zoom wasn't as sharp as either of the other two lenses anywhere apart from dead in the centre of the view. The SW appeared maybe slightly dimmer than the Altair, and the Altair showed the most colour of all of them. The SW was sharpish for maybe 50% of the field of view (50 degrees I think) whereas the Altair was sharp for 75% of the view (65 degrees so far more "usable" view). The impression with the Altair was that of a nice star field - a vista, whereas the quick fall off of sharpness with the MA and the zoom concentrated your attention to the centre. Next I eyeballed Saturn and Jupiter, quickly before they moved over next door's house and got wobbly in the convection currents. All three EP showed me small (at around 25x mag!) planets - the MA and Altair having more contrast than the Seben. I might have been imagining it, but I THINK I saw slightly more detail on Jupiter (it really was very crisp!) with the Altair but the MA certainly wasn't bad. The Seben lost out really with lower contrast on these brighter targets. Next Vega. I use this star quite a bit with the Alt-Az - if I want to observe in its area of sky I'll do a goto there first and align before I move onwards. I'd noticed in the past there is a dim star next to Vega in the 25mm EP. With the MA this star is very slightly clearer than the Altair - maybe better contrast? Finally a DSO. Not really the conditions for DSO - back garden LP and my eyes didn't really get dark adjusted but I wanted to see what I could see - the Ring nebula. Initially I saw nothing, and then with averted vision I started to pick something out. Slowly it got clearer but didn't quite get bright enough for me to look at it directly. I think it looked circular and small but bigger than a star - not sure what I should be able to see with my scope - never looked before. So my impressions view wise on the Altair - a crisp EP that does indeed seem to have a flat field of focus across a large percentage of its view. It's (very) slightly harder to use than the MA - eye position is a touch more important. I tried with specs on and off - definitely off (for me) with the eye cup turned up - turning it down didn't allow me to get close enough to see the entire field with specs on. With it turned down specs off, I could get too close and blackouts etc occurred. The spec says something like 29mm of eye relief but the eye lens is so recessed into the body of the EP that much of this is inaccessible. In comparison to the MA it's more important to keep the eye centred on the EP - I thought sometimes I could see coma half way to the edge of view but moving my eye slightly made the stars round again! It's probably at the point where the field stop is on the MA - narrower views are probably more forgiving in this respect. In the hand this EP feels quality - all rubber grip and metal fittings, pictures online really don't do it justice. The eye lens really is a piece of work - huge and concave! In summary then - a very nice EP. It's not sharp at the way to the edge on my scope, but I didn't expect it to be. It does deliver ease of use and comfort in use, a very pleasing vista of stars and a wide usable view. I spent a lot of time last night just panning around with my new joystick control - following satellites and wandering off to look at the view, which was exactly why I got this EP. It's not quite like putting your head in a bucket of stars, but it was so easy and pleasant to use that I kind of forgot that it and the telescope were there to a large degree, and just enjoyed, well, seeing....

Just as an addendum, AltairAstro in the UK do next day delivery - and I have just taken delivery of a shiny new 24mm UFF. First impressions - they need to get another photographer for their website - it looks a lot nicer in real life!

The APM/Altair seems like a fairly new design so I guess should perform well at its price point? The ES looks to have been about for nearly 10 years and is a similar cost... I'd love to be able to justify a 24mm Pan but at my level in the game the extra money would probably be better spent on a sturdy tripod! Many thanks for your wisdom gentlemen!