Rusted

Is it just me or are all the "close-ups" striated diagonally?
Particularly noticeable when scrolling.

Ah William Herschel! The real inventor of the altazimuth telescope mounting. [With slow motions!] Sadly, the world had to wait another 200 years for the invention of PTFE and Formica to bring larger apertures within the grasp of the truly impoverished.

He melted and cast his own mirrors from metal. [400!] Ground and constantly re-polished them as well as observing the skies with an early form of OCD. He was also a gifted composer and played many instruments. All the while living in an early version of Las Vegas. Which must have hindered his astronomical activities. He worked within a modest, terraced house and garden in what was once a very marshy area of Bath. His work ethic and knowledge would make the vast majority of modern amateurs look like mere, part-time dilettantes.

 Whatever the New King Street Museum has turned into. You'll want to bring a huge dose of respect, sympathy, empathy and admiration for the gentleman behind its very existence. [And his sister.]

Well done, but is the Barlow vital to proceedings? Do you need it to reach focus?

A smaller image scale would not be so badly affected by the seeing conditions.
I have used a range of five "Barlow" powers depending entirely on the seeing.
Mostly using single GPCs on the nose of the camera.

Before dismissing the larger aperture you might benefit from a skeleton tube.
Though still largely unproven, some solar imagers are enjoying success after building such "open" tubes.
I'd do some online homework on the subject before launching into a new build though.

Local seeing can vary enormously depending on time of day. Buildings under the light path, etc.
Some swear by early morning seeing. Before the sun's heat causes thermals.
My own seeing was best mid morning and [sometimes] just before sunset. Lots of big trees like yours.
This will vary from day to day and can only be confirmed by frequent imaging and/or visual monitoring.

Well done.

That rash of pores looks like a senile fly, with muddy feet, walked across the sensor. 🪰
Why senile? Because its mind wandered at half distance. 😏

Well done! 

I was trying to think what the fierce activity reminds me of:
The effects of a nuclear bomb on structures within the blast radius?

You caught the northern filaprom well. A real hedgerow in full 3D! 

I am seeing a moustache in the huge filament in the south.
The "eyes," for the face, are clearer in the inverted image. 😊

Beautifully captured and presented! Congratulations! 

A great start! 

Impressive image scale. 

You have some nice equipment and a tidy observatory. 

Many solar imagers like ImPPG for processing.
Used gently it can achieve remarkably natural and detailed results.

You are much too modest Sir.  These images are excellent.

A larger aperture is more useful for closeups. Probably not ideal for full disks.
With increasing aperture comes longer focal lengths. So image size increases automatically.
The image may be too large to fit on any reasonable or affordable sensor.
Weight increases dramatically. So the mounting and pier [or very tall and heavy tripod] can struggle.
But you know all this anyway. 😊

Superb detail on a massive scale! 

A nice set of images.

My favourites are the full disks. Both W/L & Ha. Really excellent!

That's an excellent image with lots of detail.

Keep going! Anybody who can pull off such an image, against all the odds, deserves praise and even greater success.

I had a bit of a play to give you some colour, like you wanted: I am afraid I lost some of your original detail.

A superb set of images and animation!

Thanks for the ImPPG screenshot too. 😊

Thanks. I see you've been doing this for some time. 

My image of you down on your knees on the lawn. Squinting upwards into the viewfinder. Was completely unfounded.

Your technique also explains why you are so successful. 😊

Thanks.

It would be interesting to see a direct comparison in image quality between your DSLRs and the Altair 174.
Just balancing such heavy cameras on a telescope must be difficult. Sag at the focuser is not the least of your problems.
I presume you use a wireless shutter release? Can you monitor what is on the sensor via a larger screen?
This is where you can choose your moments of good seeing with close-ups.

We'll all look forwards to your eventual foray into H-alpha.

What is your technique for multiple image capture? Burst mode?

Not tempted by a mono "astro" camera?

A great set of images! Amazing detail and superb processing.

Thanks. I am not picking on your images. Just preaching to a larger audience. Just paying it forward.

The best test of reality is to examine other's images using similar equipment and image scales.
Check out Dave Smith's image in a post nearby. His white light, whole disk image is really excellent.
If any solar image shows a uniform "artificial" texture then they are seriously over-sharpened. IMO.

Whole disks, in WL, at modest image scales, have the exquisite subtlety of an eggshell.
The limb should not be reinforced with a hard ring. Dave's image simply stops at the edge. Perfect!
Granulation is not going to show up at these image scales. Always aim for reality. Not imaginary, digital detail.
 

Dare I suggest you try ImPPG instead of Registax?
It is very easy to overcook the sharpening in Registax.
That wasn't very subtle of me, was it? 

A highly decorated solar imager offered me the same advice.
Which transformed my images to fuzzy blurs instead of sparkly snowflakes.
So I am "paying it forward."  Don't shoot the messenger. 🙊

Two words: Therapeutic accumulation.

Astronomy is a low risk, non-contact, socially non-cohesive, relatively non-competitive sport.
It usually keeps the participant within earshot. In case of spider freeing emergencies or a desperate need for spare tea consumption.
Compare this to white water canoeing, motor racing, surfing, climbing, diving and/or parachuting. As in: "Would you rather I ....?"

Q.E.D.

Follow Peter's advice first.
But, if you cannot remove the top piece, then try using a suitably large screwdriver to hold the nut still.
Push the screwdriver gently past the edge of the nut to hold it by one of its flats.
While you turn the housing in the direction to tighten the nut. Probably clockwise if it's a normal nut.
It might be possible to get it tight enough so that friction with the nut and the surface below it will tighten it fully.
My fuzzy logic suggests that something comes off to allow access to that nut.
Anything which is assembled must have been in pieces when it mattered.
How else would they have tightened that nut? 😉

Your fiddling with the slow motion was probably in the incorrect direction. Anticlockwise?
So you overcame the friction between the nut and what lies below it.

Stunning detail and an incredible sense of perspective.

Your seeing conditions must have been truly extraordinary at the time you captured data for these images.
This is not to take away anything but breathless admiration for your skills.

Will solar imagers now descend on Hastings? Like they do for an eclipse? 😊

Buy Daystar! Quark sales will be going through the roof!

Indeed. Not all obstacles to light pollution are fixed nor even solid.
Raise or lower a dark cloth blind on posts with pulleys only as needed.
Louvers block light from certain angles. Pass it freely from others.
Light blocking vegetation can be conifers in big pots on castors.
Just be careful about the force of the wind on your contraptions.

No, no, no! You want an f:15 refractor to use as "proper" baseball bat.
A 75-80mm should do it. No need for an APO.

14 minutes ago, Ags said:

There are a few aspects I am not sure how to solve. Although I can build a big wood box, I am not sure how to guarantee the roof rail end posts will be square with the shed, and that everything will be truly parallel. It looks like there would be very little tolerance...

Maybe this book would help... has anyone seen it before?

https://link.springer.com/book/10.1007/978-1-4939-3011-1

Not seen the book I am afraid.
If you have one set of fixed wheels on one side...
you can have the wheels [on the other side of the roof] sliding along their axles.
It won't need much lateral movement. Just enough freedom to avoid binding.  
V-pulleys running on rails are popular. The rails can be angle iron for a firm fixing.