Rusted

I think I'll wait for all the box opening videos.
That will tell us everything we need to know about optical quality.

The tail end extension tubes looks like compression fixing devices on the larger scopes. 
Capstan radial bars. Suggesting [to me] options for locking at any user-chosen length.
Always prepared to be proven wrong. 😊

I have a 3.5" FT on my f/12 iStar achromat and can vouch for the weight. Handy for balancing a heavy lens and its cell though. ☺️

2 hours ago, johnturley said:

The 185mm would be potentially great for high resolution planetary/lunar imaging, depending on the quality of the lens. I find that my Esprit 150 gives better results than my 14in Newtonian, unless atmospheric conditions are very good.

It would however require a suitable mount, maybe an EQ8 or CEM120 (expensive), although the mount is not as critical as with deep sky imaging, some planetary imagers produce excellent results with dobsonians.

John 

Thanks John. Seeing the 185 being [carefully] cuddled really brings home the proportions.
My 180mm achromat is in an 8" Ø tube. 185mm is 7.25" so even bigger. A handle is almost essential.
Too big a diameter to get your hands safely around it to lift it onto a mounting IME.
Particularly when you take it down again in the early hours covered in ice.
Don't let me put anyone off though. That's a lot of APO at any price! 

Just curious: Which mounting can easily handle the weight and length of the 185mm for high res, planetary/lunar imaging?
Or wouldn't it be suitable for such tasks? You don't buy a telescope in isolation. It needs to be held rock steady. 

Nicely captured, quiet sun. 

Though with lots of filaments and considerable flaring in the west.

Perhaps the prom in the east will drag a new spot around the corner?

Thanks.

Sorry I missed your tiny text with my ageing near sight.
I was curious to compare your results with your various instruments.
Your superb images will hopefully inspire others to try their luck.

What monitor are you using for your image processing following capture? Surely not the HP?

As an aside I think it would be useful to add some small text to your images to show the instrument, Barlow and camera used. Perhaps even the mounting. Having rushed through your thread admiring the many images I must have missed mention of your mounting. Having this basic information to hand means others can compare their own progress as they attempt to emulate your very high standards. 

My "best" casually captured images of the moon are taken with a 150mm f/10 achromat, 2x Barlow and ASI174MM. While I managed to capture three small craters within Plato the image is full of over-sharpening artefacts. I would not even consider sharing such an image beside your amazing work.

Nigella, while Team Rest of The World struggles to produce a single acceptable image. 😶‍🌫️
You lavish us with a whole portfolio of truly exceptional work! 
Are you deliberately trying to make us feel inadequate? ☺️

I am far too polite to ask if you have one short leg. [On the tripod!] ☺️
Blocking the headlights on the road might be a consideration for next time.
But only because they are a distraction for what is going on overhead.
Can you move to the left to use the buildings in the foreground as a mask?
Quicker than waiting for a hedge to grow.

As to the clouds? You are naturally forgiven.
Though their haste and colour does add drama to the scene.
Nature abhors we pesky humans! It should be obvious by now.
 

Hope this helps?

1 hour ago, Mr H in Yorkshire said:

It's about that much here. It's more fluid than many similar products. Should you use it, I found it best to wide mask either side, put down a bead then really squeeze it into the joint so that it grips/sets on all the interstices and irregularities. 

Thanks.

46 minutes ago, Mr H in Yorkshire said:

@Rusted I've been introduced to C-TEC CT1 adhesive/sealant by my local Dales Hardware/Agricultural merchants. They recommend it to all their customers as the best there is and they have never been wrong in their advice. It is pretty new on the market. I have now used it in a number of situations including polycarbonate to wood. It is definitely up to the recommendations. It comes in clear and a range of 'building' colours. I have no idea if it is available in Denmark.

Thanks. I'll do some homework on the C-TEC CT1 but it may already be too late.
It seems to be widely available over here at around £10 equivalent.

Thanks. I used the most expensive "marine" quality cartridge sealer.
It was hopeless. Some kind of tape might have been [theoretically] better.
I don't know of any suitable for the job.

12 hours ago, uhb1966 said:

@Rusteddont dismantle your obsy, it's the coolest we got on this forum!!!

Thank you for the kind words but several, serious problems arise. This is not my thread so I'll try to keep it brief.
Though there is a warning here to others considering building high. Or considering building a plywood dome:

The 10' plywood dome leaks like a sieve at the joints: It is far too difficult and dangerous to apply GRP over the entire dome so far from the ground. Cherry picker + time + huge expense for materials. I no longer want the smaller, 10' dome anyway. The 2-storey building has already been enlarged to 4.3m Ø for the larger dome. The old [leaking ] dome has to come down before the larger one can go up. Which means crane hire. A larger top ring and rollers must be fitted before the larger dome will fit on top. The 4.3m dome is an unfinished project. Which means risking working on an unsafe dome high above the ground. My motivation is at rock bottom. So I am trying to give away the 4.3m dome and then dismantle the entire observatory.

2 hours ago, 900SL said:

You could guy a pole using post tensioned rigging (like a yacht mast). Thus would significantly increase the stiffness compared to a freestanding cantilever.

Much the same effect, but far less bulky, could be obtained by attaching [minimum 18mm thick] longitudinal, plywood ribs.
Like the welded piers but extending the entire length of the taller pole.
Glue is very unlikely to work on a pressure treated or tarry telegraph pole. BTW: These poles can stink depending on age.
Metal strap clamps make more sense for rib attachment. Even if it means cutting windows in the ribs to thread the clamps through.
Anything which projects from a pier is crying out to be caught by the telescope[s] at some point of normal sky coverage.
Remote operation would require cameras and monitors to avoid tangles or obstructions. 

Thanks for your understanding.
There is masses of detail hiding in your original image.
It deserved to be seen. So I just shone a brighter light on it.
It is very easy to go overboard and produce an artificial sharpness.
I hope I avoided that, even in the second image.

I was curious to see what was hiding in the murk. A few seconds adjusting Gamma, contrast and auto levels:
1st NO sharpening: 2nd sharpened. Resized down to 1000px for posting. Feel completely free to disagree with my clumsy handling.

What a difference the date makes.

Nice images! 

But no sandbags required! 😄

Babet? 😱

Short piers can get away with far more sloppy building skills than tall ones.

Remember that joists are laid on edge. They are also supported from both ends.
The stiffness rises as the cube of the timber's depth. Use depth, not width, in your designs.
Make everything multi-purpose in stiffening your structure. Turn depth at 90º between each member.
A four sided structure with [stressed skin] sheet covering becomes even stiffer.
 
The "four poster" wooden pier threw away enormous potential in bolting the posts tightly together.
Spacers would have increased the cross section, stiffness and spread the vibration modes.

Small spacers at the top and large spacers at the bottom would triangulate the structure.
Cover the newly tapered structure in plywood and you have a smarter design with far greater stiffness.
Such a design would have avoided the stresses of warping of the individual posts.

Use the carport anchors at ground level to support each post.
You gain fine control over levelling and have avoided the vast, ready-mix lorry leaving tracks across your lawn. 😉

9 hours ago, WolfieGlos said:

Now that’s interesting, we caught something similar in northern Norfolk the other day which looked unusual to me. I honestly didn’t know what it was and assumed it was linked to the cloud, but it looks to be the same and had the inverted bow at the top - just visible in the second picture. What I can now see on the photo is a faint second ring underneath it too.

Thanks for posting this! 

 

 

Thanks for posting these. You have definitely captured the [more common] solar halo.
The colourful, inverted, circumzenithal bow or arc above is also clearly seen.
If you play with gamma in your images you can emphasise these effects for greater contrast.

I had falsely imagined that a northerly or wintry viewpoint was required.
Now it seems that the relevant ice clouds can form at more normal altitudes.

I did an image search for atmospheric solar phenomena but had to add "arcs" and "bows" to get anything useful.
Wikipedia, in particular is very poorly illustrated for atmospheric solar phenomena.
I have seen quite a few sun dogs and haloes myself. Many lunar haloes too in the right conditions.

Thanks. The text, in Danish, talks of the rarity of the ice crystals involved forming simultaneously.
Normally these are six sided but can be of many different forms. It required high altitude cirrus [ice] clouds and high winds.
The crystals must be clear plates and arranged at very specific angles. Some have to lie horizontally.
While others must be vertically orientated. Others at 22º to achieve the bows.
All with recognised names. [Language dependent of course]
If you realise that bue mean "bow" then the Danish description makes more sense.
The images were taken on the northern tip of Jylland/Jutland.

The Danish DR News and weather website is showing some rare solar images taken by Troels Nielsen from Skagen.

All rights belong to Troels Nielsen and Dansk Radio but the images are so spectacular that I wanted to share them with an interested audience.

Note that I have reduced gamma to increase the contrast without blowing out the highlights. I also downsized the image for posting here.

The following direct link leads to the article written in Danish:

https://www.dr.dk/nyheder/vejret/spektakulaere-og-sjaeldne-haloer-set-over-danmark

Rough translation: DR DK News/Weather/Spectacular and rare haloes seen over Denmark.

1 hour ago, 8324689 said:

Thanks for this and let me ask just for a final time. (Sorry if I'm flogging a dead horse!)

Would not a wooden telegraph pole 1/3rd submerged and 2/3rds exposed in the earth with concrete not be solid??

just for a C8 and HEQ5 

thanks again 

 

Height to the top of the post?

4 hours ago, bwj said:

@Rusted , looks like a great observatory. I you look on Cloudy Nights, in their observatory forum, there are several examples of people who have built observatories on their garage, etc. The piers run down to the ground.,  some using concrete blocks, some pipe. Rusted's pier support would definitely be easier and cheaper.

Thanks. After a long running thread on my observatory build, on C&N, they finally got rid of me.
Because I kept mentioning H-alpha telescope mods in answer to queries. Which were banned from discussion.
I was using a 6" f/8 modified PST myself at the time. You can blame Peter Drew for that. 😉
Fortunately H-alpha telescope mods are discussed at great length by some very clever people on SolarChat!! forum.
Where progress and understanding of the safety, limitations and advantages of modding continues to this day.

A free standing post is very unlikely to be successful.
The taller it is and the higher the loading the lower the resonant frequency.
And, the longer it vibrates at the slightest touch. Because it has such dreadfully poor self-damping.

I tried a steel pole. Hopeless. A steel pole full of sand. Hopeless. A steel pole dull of concrete. Hopeless.
My pyramid of four timber posts uses geometry and the natural damping of timber. Common metals ring forever.
Every force applied at the top of a pyramid is resisted by the opposing legs.
The cladding stiffens it further. Though one has to be careful or its weight will form a vibrating plate!
I had to remove some cladding to damp the unintended resonance.

It still wasn't perfect. Despite having a couple of hundred kilos of my DIY equatorial mounting on top.
So I had to isolate the imaging desk entirely from the pier. As well as isolating the building from the pier of course.

My plan was to avoid leaving any trace of my observatory building if I moved or died.
I can dismantle the whole thing and leave only the gravel on the ground behind.
I shall probably do that next. Though I hope somebody will take away my 4.3m/14' GRP dome.
So I have more room to work. Though I have no plans to move away. Nor dying yet.

IF you are willing to cast a huge foundation block you could build a precast chimney block pier.
I wasn't willing to leave such a carbuncle for the next owners  It wouldn't be fair to them.
Cast your concrete with that firmly in mind.
My carport anchors, in sufficient numbers, will support a two story building. Or a tall pier.
I used eight on the original octagon. 14 anchors on the enlarged building.
Four more on the pier on the largest circle I could manage within the building.

Thank you for your empathy but I am happy to advise if I can.

Trees were my problem too. The problem with trees is that they continue to grow.
Unless you are the owner of the trees and the land on which they stand you are powerless.
Even then you may be subject to tree preservations orders.
Assume that neighbours will hate your "monstrosity." I was lucky and live rural detached.

My raised observatory was designed to be dismantled if required. NO NAILS!

My method of safely gaining height for my home made 3m/10' dome was the use of 4x4 [10x10cm] sawn timber uprights.
These were mounted vertically, on the adjustable, galvanised brackets of concrete, carport anchors.

I made an octagon with an outside, fenced balcony. For safe access during outside dome maintenance.
A mitre/circular saw was used to accurately cut spacers in 2x4 [50x100 mm] and 2x 6 [50x150mm] timber for reinforcing rings.
Floor joists were 2x10, 2x8 and 2x6. As recommended by skilled US carpenters on another astro forum.
From which I was subsequently banned.

I used lots of 'Climate' and galvanized coach bolts. Torx wood screws too. Using high quality driver bits.
I should have had a rechargeable screwdriver but used an ordinary rechargeable DeWalt drill instead.
Which lacked the guts to drive 100 and 150mm screws. So I needed to use the Drilling mode.
Which caused repeated wrist injury due to twisting without a safety clutch.

The timber skeleton was then clad in 12mm decoratively grooved, exterior plywood.
Using countless screws to obtain a stressed skin design.

I bought an aluminium, warehouse stepladder for access to the observatory floor.
One of my wiser decisions. Never accept a normal ladder as a means to a raised platform or observatory.
You need flat treads for balance and stability when climbing with delicate, expensive, large and heavy equipment.
Shelter the stepladder, if you can, to avoid ice and snow build up.

My 14' pier was a simple pyramid of sawn 4x4s. Partially clad in 18mm exterior Baltic birch plywood.
Standing on four more carport anchors at maximum radius to fit inside the building.
I climb inside the pier via  the stepladder for access to the obs. floor.

The floors were larch terrace boarding and hideously expensive.
I have tons of pictures but you'll find my entire build on my blog in my signature:
I worked entirely alone at the age of 70-ish in 2017/18.
My blog has dozens of posts illustrating progress.
The endless text describes my ideas and design decisions at great length.
The pics below show the completed skeleton. Then the observatory after a couple of years of weathering.