Ags

I think I have it close enough for a first photo. Stars are round and pointy on axis, I may need to do a few iterations to clean up the corners but I draw the line at collimating in a fine drizzle!  The clouds got too thick to check the corners  after tightening the locking nuts on the primary, but it was looking ok at last check.

I haven't noticed FC much with the Svbony 3-8 despite using it quite extensively. I see the appalling FC of the Nirvana 16 clearly, so we agree on that! Next time I have a clear but Moonish night I will try it out again, paying more attention to the edges. Did you see this at all focal lengths?

I have given up on the Cheshire as a collimation aid. It requires common sense and judgement, which isn’t something I’m noted for! I have switched to using my camera, and made good progress tonight. Collimation is not perfect yet but it is a lot closer than ever.

No need for a second scope for polar aligning, it can be done with the imaging scope. That's how it's done with an AsiAir after all. So all that is required is software support and a wedge. Not sure if ZWO would need to strengthen the RA wheel.

Yes I remember that Mars opposition - I travelled to the Canary islands for a better view, and Mars was completely featureless!

OK, so the plan is: ES 16" dob, Geoptik EQ platform, Starsense. I'll be able to manage all components by myself if needed, and everything will be easy with an assistant. 

I see the ES dob is a bit tricky with balance issues, but I am not one to change eyepieces frequently (or a fan of big eyepieces) so not too worried about that. 

Regretting I wasn't braver last night. I should have had a go at those collimation screws last night!

It was not a night for astronomy but stars were peeping through the complex, multi-layered clouds so I went out to test the collimation of my RC6. The collimation still has a way to go (primary screws overtightened), but I stuck in a 20 mm eyepiece and tried a few low power targets . I had quite a pleasing view of some brighter doubles like Mizar. One benefit benefit of the pinched optics was that stars were slightly defocused so star colors were accentuated. Really impressed with the purity of colors in the RC. 

I was using my FMA135, ASI120MM and ASIAIR as an electronic finder to zoom to a few targets and it worked really well, although of the galaxies I tried only M81/M82 were bright enough to peep through the murk. On a better night, using the AIR&co to quickly find targets will work quite well I think.

Tonight the stars were just about visible through several layers of cloud, so I could do a star test. A defocused star looked almost symmetrical, but the became triangular closer to focus. This means, i think, that I was too enthusiastic in tightening the screws on the primary mirror. I I'll back these off tomorrow and try again.

Great info, thanks @seven_legs!

The scope would be set up permanently in my dobservatory, so I think I should be able to keep the mirror clean.

I thought straps were the usual thing for large mirrors, to prevent pinching the optics?

Can I ask how the scope performed at mags above 300x?

15 hours ago, TiffsAndAstro said:

Are there any such scopes that are easier to deal with?

Maybe an RC? (Evil laughter)

Very sad to hear. I learned a lot from his articles when I started out.

I'll have to think about the weight. The Stella Lyra 16" is a great price and looks mechanically superb. If I ever need to move the thing, I'd need to summon a posse.

Thanks, that's a lot of detail! It does seem unfortunate the design puts the bulk of the weight into one component.

I am idly dreaming about the observatory I will set up when we move several degrees south next year. We should land in Bortle 4 which is a chunk better than 8 - although I read Bortle 4 is very wide with good end and a bad end...

I think my little HEM15 is all I need for deep sky AP, EAA, visual smartscoping and so on, but I do want something bigger - a lot bigger - to get really close in on the Moon and planets. I need a lot more aperture to compensate for my snowglobe eyes that won't let me use small exit pupils. Also I want to go as far as I can with planetary imaging, and that is one field in which aperture is absolutely deterministic.

I have been designing a dobservatory - a low-walled ROR obsy to house a larger dob on an eq platform. The dob would be permanently set up in a fixed position, but keeping weight low would still be a priority as things need maintenance and even the strongest eq platform can do with less load... The ES 16" caught my eye - it seems quite a good price and the overall weight is not too bad at 38 kg, although the mirror box is 23 kgs.

If money is no object (really depends if I can take my work south with me) then the Taurus T400 is the other option at twice the price - 31 kg total weight, heaviest component 18 kg, and 1/8 pv optics.

Does anyone have experience of the ES - how is it mechanically and optically? I think with an EQ platform and starsense for DSOs it should be pretty nice.

These are very nice pictures! I can relate to short integration times... So much sky, so little time 😃

True, I have a pronounced nasal protuberance. Maybe the device is intended for those not so blessed.

Yes exactly, and while it is capturing relatively long (a second or two?) exposures, your nose is bumping the smart eyepiece....

Also, this is just another spin on EAA. But when I do EAA, a camera is plugged into a scope and I am viewing on a screen. With this thing you are viewing through it, so the scope will be less steady - not great for longer exposures and live stacking....

No. Just no.

Why open the telescope box, set up the telescope outside, and look at dim fuzzy objects, when you can look at the colorful pictures on the telescope box instead?

I spent the morning, day and evening eyeing clear skies, but now that night has fallen the clouds have closed in. Really feeling like the sky has something against me!

I like being out in the dark, so no remote roboscopes for me. But getting an ASIAIR has made imaging so easy and hassle free it's really feasible to set it going and switch over to some visual fun with a grab and go setup.

Even though you thought you could never lose your mojo, you're now falling into the same fallacy of thinking you'll never get it back 😃 You'll see, it only takes a little spark to relight the fire!

Tested on a neighboring tree, view looks sharp at 150x, less so at 225x, but it’s hard to judge by day with the razor-thin depth of focus. If the weather stays like this, I should be able to do another star test tonight.

Not sure I can get closer with a Cheshire. Tonight the stars!

The bigger the star, the higher the pressure in the core.