Stub Mandrel

Commentary was a bit feeble, lacked immediacy. They still haven't worked out that a bit of blu-tacxk to stop the USB cables on their webcams vibrating loose might help. They never replied to my tweet suggesting a drone mounted camera to film the landings - I suspect they want to be able to cut the feed if things go awry without raising suspicion so a bit of unreliability is good...

Great image, Mario.

But if the star light is absorbed and re-radiated as a blue halo in the cloud layer...

Here's a theory. When focused on infinity, a cloud layer will be slightly out of focus. For a 1 meter scope, if the cloud is 1km high it will only be 1 micron out of focus. Refraction effects in the atmosphere might increase the focus difference, under the right conditions. Thin, low, cloud preferentially scatters blue rather than red. As a bahtinov mask is very sensitive, this very slight out of focus could be enough to create a superimposed blue image that is slightly displaced compared to the original one. As the only the blue elements of the pattern would be affected, this would turn each spectrum into a short, curved segment. This images of a BM pattern through a Ha filter shows how red light is 'grouped', imagine the dark parts being made up of blue light, then shifted as if out of focus

Shine has gone off a bit with Musk's shenanigans. Perhaps they should pot his ego on board? ?

The way it curves (presumably along the lengths of each little spectrum on the pattern) suggests its related to dispersion combined with the diffraction effect of the mask. Is the focal reducer at the right spacing? - Perhaps try the setup without it.

I have seen a similar issue when my ADC is fitted, as the six spies are 'rainbow coloured' it curves the whole thing.

It's more informative to use arc seconds for the x-axis than pixels as it doesn't depend on the camera. The 0.91" RMS (at left) is more informative than the 0.19 pixels.

I think gradients go hand in hand with any degree of light pollution, even a nearby bright star combined with some light, high haze can put a gradient across your images.

Congratulations! Just to help folks find it: https://www.skyandtelescope.com/online-gallery/m7-ptolemy-cluster-2/

No! Each entry must be a new topic per image. For future competitions it seems they will be in a gallery instead.

Or buy a quality kit.

... another one bites the dust! I think the point of this thread has been achieved. Those who say that an EQ3 mount is unsuitable for astrophotography are demonstrably talking rubbish. It's an ideal route into learning the ropes with the expectation of being able to get images you can genuinely be proud of. Having now got a little experience with the HEQ5 I can honestly say that the differences are chiefly that the EQ3 needs more frequent tweaking, as it is less tolerant of being out of adjustment than the HEQ5, particularly in DEC, and that the aluminium tripod is inferior to the stainless steel type. The EQ3, on a steel tripod, matched with an astro-modded camera and a 130P-DS is a relatively affordable and rewarding route into deep sp[ace astrophotography.

Excellent prints and design! Puts my basic (and so far unused) dome to shame. What camera are you using. Which version of the ultimate camera is this? <ducks>

The one that came with my Celestron C90 doesn't do this, at least not that I have noticed.

Have you seen the new 'ironing' feature in Cura? - It smooths the top layer. Seems to work well, but leaves unexpected 'zits' where it stops and starts.

I think a worm cycle for the HEQ5/EQ6 with 144 teeth on the worm wheel is 10 minutes , so I'd hope 30 - 40 minutes would be sufficient?

I've got an HEQ5 as well now. I'm a bit of a bearing upgrade nerd (I've done my lathe and my mill and fitted needle thrust bearings to the EQ3) have a mate who used to import them in a big way (still does but limited range), so he can advise on best choice (I suspect he would recommend Nachi).

Except for those of us who find it a major effort of will to remember to park the mount before switching it off...

It's a beautiful little wide field scope by the looks of it, but I remain to be convinced that scope optics are the limiting factor for guiding. My guiders use cheap achromat elements from Astromedia and its definitely the mount, not the guidescope that's the limiting factor.

I thought it looks a doddle - but I am familiar with that sort of job.

The Rowan Belt Mod looks well thought out...? Actually was guiding low and with the scope on the on the east side last night, wasn't as good at about 1.03" Took a bit of fiddling with settings to get that - mainly reducing the aggression as it was overshooting. I think problem was that it was west heavy making the RA tracking 'jumpy'.