Captain Scarlet

You can safely remove them, they are for a finder bracket, allowing the finder to be “above” the dovetail whichever side of a mount you set the scope.

I also very recently got around to comparing what I was supposed to be seeing (sky safari pro) with what I was actually looking at and was gratified to notice those moons too! Only a couple of weeks ago. So I can feel your joy! M

Fair enough re all those other types of targets. Regarding European really dark sites, there are not many easily accessible. I’ve based myself partly in extreme SW Ireland which is one of those places, and a big dob is on the wish list. I have a 12” but hanker for twice that. M

The trouble with very large aperture scopes is that the minimum magnification for a standard exit pupil gets too high, unless you go ridiculously fast. For example, 1000mm aperture f/3 with an exit pupil of 7mm implies minimum youthful magnification of 143x, and even higher if you’re older! That completely rules out extended nebulous objects which is what the large apertures are primarily aimed at. M

A few months ago I posted a big piece called "reverse engineering a skymax 180". Part of my purpose was to establish exactly what focal length the scope was operating at. I initially assumed one important parameter by making the assumption it was 2700mm with the supplied accessories (51mm visual back and 2" diagonal). What prompted me down that route was a similar experience to yours: it seemed to be giving me more magnification and less FoV that I was expecting. Over the next day or so I am about to update my post, having done the extra work to exactly pin down its focal lengths, and it turns out that with the supplied accessories my 2017 Skymax 180's focal length is actually 2883mm +/- 16mm. This explains the reduced FoV and increased mag. Cheers, Magnus

I often wonder how accurate the centre spots are, especially as they're often such a key part of collimation. For a big newtonian primary it must be quite difficult to establish precisely where it is (the true optical centre, not the centre of the "slab"). For a small secondary, as long as you're prepared to remove it, it should be fairly easy to find on a hobby-sized lathe.

Fascinating. My favourite part was "There is no surviving portrait of Robert Hooke, since it is thought to have been burned by his rival, Sir Isaac Newton"

I have a canon 24-70 2.8 L lens whose autofocus has stopped working. The front filter ring has a dent in it, though I have no idea how it happened, I have certainly never dropped it. I suspect the two problems though are not unrelated. thanks for the recommendation, I may get in touch with them... M

rather than type out a thousand words, I’ll attach a link to my own journey starting from the exact place you’ve started: http://www.slidingseat.net/stars/stars.html#startingout hopefully the site works ok on your browser, seems to like a computer rather than phone though... the he short answer though as alluded to by @Skipper Billy is dark skies, tracking if you can, and stacked multiple exposures. 3x45s worked for me cheers, Magnus

Nice. I had a very nice view of Uranus tonight with my own 12" newt, a startlingly obvious disc, but it didn't occur to me to look for moons. Last night I did look quite hard for Martian Moons but couldn't see anything despite looking up where they were supposed to be. Neptune's and Uranus' moons are next on my list now. Our Moon is getting less obtrusive over the next fortnight so with luck I'll get more clear nights. M

Yes it has been fixed for iOS, I regularly run Skysafari pro and the synscan apps together on one iphone to control my az-eq6-plus-wifi adapter, which i believe is the same protocol as the az-gti setup

Yes I've had that exact experience too. With my Skymax 127 I looked up to see how long I had before Saturn went behind the big Magnolia, and found it'd been behind it for a good few minutes!

As per @Andy0306 's suggestion, I've ordered a pair of these https://www.theheatcompany.com/en-gb/gloves/merino-liner?number=33022 . I'm also going to steal a pair of my wife's thin woolly mittens.

I've been commuting to work by bike since the late 1980s and it took me years to solve the what-gloves-for-70minutes-when-it's-cold-and-raining problem. My only truly miserable rides were that scenario. It turns out there is no such thing as a cycling glove that's waterproof. But eventually, only quite recently, I found a pair that is completely impervious to water even for a whole 20 mile cold wet ride, but they're not cycling gloves! They were Montane trekking gloves, layered pertex, and have made such a difference!

not too cold by temperature measure alone, but where I am there's no place with protection from a stiff cold NE wind: at 2-3 degrees with that wind I've been forced to abandon observing sessions fairly regularly due to numb fingers. Once I even had to contemplate leaving my whole rig outside overnight as I barely had the dexterity to undo the saddle-knobs to get my 12" off the mount.

Christ!!!! I think the Heat 3 Special Force should just about suffice 😳

Another surprising thing that sticks in my mind is that a photon created at the centre of our Sun takes on average 200,000 years to get to the edge, I seem to remember reading...

The most important thing in Newt collimation is getting the 2 independent axes lined up and coincident: the focuser => doughnut axis; and the focuser <= doughnut axis . The lining up of the edge of the primary with the edge of the secondary, while worthwhile, is far less serious if you don't get it quite right. By lining up the edges you're placing the secondary's edge on the edge of the primary light-cone. If you don't line the edges up, all it means is that one part of the secondary is outside the primary's converging light-cone and hence "doing no work", and the other side of the secondary is a bit too far inside the light-cone and hence missing some available converging light. It just has the effect of slightly effectively reducing your aperture and giving you slightly uneven illumination which for visual you wouldn't notice. Summary: Fail to line up the axes properly, you get actual aberrations. Fail to line up the edges, you just miss a bit of aperture and illumination. BTW that Gannet was about to plunge into Lough Ine in Ireland, there was one that frequented the Lough last year, a young adult I think. Lovely creatures. Cheers, Magnus

A thing that often confuses is the fact that there seem to be lots of crosshairs around! ... actual ones and reflected ones, and the reflected ones are clearer because you can actually focus on them. In this case what you're trying to do is align the focuser axis to bounce off the secondary and "hit" the doughnut. (the "outbound ray"). Your eye is at the centre of the focus tube. The actual crosshairs are also at the centre of the focus tube, at the other end of it, but they'll likely be a bit out of focus as they're so close. If you line up those crosshairs with the doughnut, you're guaranteed that your (centred) eye, the centre of the far end of the focus tube, and the doughnut are all in a straight line (albeit bounced off the secondary). You make these adjustments by finely turning the secondary's tilt screws. THEN, you adjust the primary tilt to get the primary's axis (the "return ray") to coincide with the outbound, by getting the reflected (smaller and not fuzzy) crosshairs to coincide with doughnut. I hope that makes sense

Thanks everyone, lots of options here. I hadn't realised there was such a thing as dedicated astro gloves, but applying a second's thought, given everything else that's available, of course there is! I probably won't start smoking though M

... and use the Atlas 2015 layer for its estimate as to what best darkness to expect.

Lightpollutionmap.info using their Atlas 2015 overlay/analysis I have found to be very accurate at two completely different sites. I spend time between SW of London, Bortle 7ish 19.05 and SW Ireland, Bortle 3ish, 21.80. I have an SQM-L meter and have collected around 200 quite recent readings from each at various different altitudes and phases of sun and moon. At each site the Atlas 2015 estimate matches almost exactly what I have measured under best conditions, even now. I regard that as a reliable guide as to what to expect. Cheers, Magnus

I clear my secondary mirror of dust by using a gardener’s water spray. I fill it with distilled water, set the nozzle to “jet”, point the scope tube slightly down so the dripped-off water runs out through the front, and fire the water jet through the open focuser tube onto the secondary. Being distilled, it dries clean.

The Winter season is rapidly approaching in the N hemisphere and here in quite-dark-land I find winter nights to be some of the most sparkling and crisp. I have Uggs for my feet, thick trews and a lovely thin but incredibly warm down jacket. But I haven’t found gloves yet that are sufficiently thin and supple to press small buttons yet warm enough to be handling aluminium objects in the cold? What do you use? M

Thanks. It was a Canon EOS 7Dmk2 with 300mm f/2.8 lens and 1.4x converter, making it 420mm f/4.0 . 1/2000s f/4.0 ISO400 was the exposure, shot as RAW. The Moon was bright enough that autofocus was fine, and it was hand-held. IIRC I used auto-exposure but under-exposed by the auto measure by a couple of stops, I find that allows the best dynamic range for images including very bright objects such as Moonshots or sunsets.