Rusted

Congratulations on having a gorgeous instrument to play with Rod. Though I wouldn't want to confirm image orientation in a hurry. A long lecture: The sheer scale of such a professional instrument should be noted by the over-ambitious refractor "wannabe." The great length of a "normal" straight OTA means that the moment is huge. [mass x distance from the fulcrum] Which easily exceeds the ability of most commercial mountings to keep things under control. Forget anything under £10K if you want to go commercial equatorial. Or you will regret it from first light until you sell your "white elephant." D&G has a list of suitable mountings in its FAQ. I'd say it is anything but conservative and assumes a sturdy pier of adequate height. Plus very deep pockets. Or the skill to build an adequate mounting from scrap. Or know a "tame" builder like Peter. The real reason for APOs existence [IMHO] is the total lack of affordable commercial Equ. mountings with the ability to carry a 6"+ classical achromat. They offer living room finishes instead of heavy engineering. Because they know the vast majority of owners will want to carry the mounting outside. So they can't sell REAL mountings because so few will ever want to buy them. They bring a decorative, folding pocket knife to an artillery gunfight! iStar optics sell far more short focus lenses than classical. We still gape in awe at classical refractors because there are so few of them. Long OTA? Add a prism or a heavier eyepiece and you must immediately compensate to achieve OTA balance. Sliding weights help but add to the moment. You can't put then on a silly, short saddle because they have no moment sited there. You certainly don't want to be repeatedly lifting such a weight loaded instrument on and off a high mounting. I had to make a multi-pulley hoist just to change OTAs in my dome to avoid literally killing myself. That also means the mounting must be fully secured during every change of instrument. Or give up regular changes as I did, in the end. I hadn't built in positive shaft locks and relied only on the big wormwheels and multipoint friction clutches. The first time I tried swapping OTAs, without tying off the mounting counterweights, the 7" nearly batted me right out of the slit! Then you have to change heavy counterweights to match the new OTA. I use a sturdy prop to support the Dec. shaft slightly above horizontal. Without it I'd be completely powerless to change OTAs. I use multiples of 5kg weights. Because I couldn't handle anything heavier while perched on a sturdy stepladder. A 7" f/12 is hardly a big instrument by refractor standards. You only start getting serious at 8". Which means f/15, or more, if you want false colour under control. What does a 7" REALLY look like? This is only the stubby dewshield. The REAL one is 10" in diameter and nearly 2' long. [2.5x aperture.] BTW: I'm about 5'10" and 73 years old.

Thank you Daddy! In reality, your skills and achievements totally eclipse my own, very humble DIY ATM. The folded design is crying out for extended collimation rods back to the eyepiece. Then you can watch the changes you make "live" instead of endlessly running back and forth. Then forgetting why and what you just did and making things much worse. Another roundtoit.

Hours of cloud and seconds of sunshine. The worst seeing in recorded history. Off axis illumination I can't cure. Am I having fun yet?

Thanks. I try to keep the builds "tidy" but functionality the most important aspect. I made a 12" Dob from scratch decades ago for somebody I never met. A friend of a friend. He could have been profiting off my hard work for all I know. Huge effort went into achieving a decent mirror [plate glass] and the finish on the varnished birch ply. Made to a tight timetable [with nagging] and I hardly broke even on the materials alone! That put me off making telescopes for other people for life!

I still have a brass, push-pull focuser with RAS thread and two simple, RAS eyepieces to match. 1/2" & 3/4". Possibly Hinds and late 1950s? Bought from a dealer's advert in Exchange & Mart I think. My first DIY telescope [early teens] was a 60mm 1/2 diopter [2000mm focal length] spectacle lens in a home made "aerial" telescope. I still have the "objective" lens somewhere. Covered in Plasticine from being held in its plywood mount. Built using only a hand wound drill and padsaw handle with a broken-off hacksaw blade. The OTA was hung from the washing line post in the back garden. I saw a colourful Saturn [very] briefly at a ridiculously high magnification!

Hi Dave, Wot Peter said. He's the professional. I am the bumbling amateur. Most of my stuff is built from scrap metal. Here is a random selection showing my home made equatorial mounting with 50mm shafts. The other mounting is my old Fullerscopes MkIV with 1.25" stainless steel shafts. My blog has images scattered throughout of my various telescope projects. The massive, mobile pier under the MkIV was to cope with our high hedges and trees. It is very unsafe to push around due to its high CofG. The dome is 3m diameter, self made from plywood and mounted on a hexagonal building. All DIY working entirely alone. The Newtonian project is an ongoing 10" f/8 with a premium mirror.

With the direct experience of owning a 7" f/12 I suggest that the cardboard tube was no lightweight. I have grave doubts that the cardboard tube of the 12" was remotely stiff enough. I laminated a 12"Ø cardboard tube from commercial concrete piling tubes in 1/4" thickness. It was only 2m long but sagged overnight between end supports and constantly went out of round. My own variations on a theme of tubing materials all weigh much the same as each other. Thin steel/thicker aluminium/thicker cardboard/PVC/plywood rings and tubes or dowels. Even CF and modern Tufnol! I finally settled on straight seamed, steel extractor ducting for my 7" f/12, 6" f/10 and 5" f/15. Rolling a multilayer, aircraft ply tube, laminated around thin, structural baffle rings is good. This was lightest tube I ever managed to make for my home made 5" f/15 but very hard work to get right. The mounting of the 12" looks so utterly inadequate that I doubt the image stayed still for a fraction of second at a time in still air. My far more modest 7" f/12 exceeded the limits of my Fullerscopes MkIV for serious use. I made a folded version but it weighed much the same as the straight tube version and was very bulky! Collimation is a bore and avoiding stray light even worse. Be warned unless the folded OTA is permanently and adequately mounted. A compact folded refractor is impossible to baffle properly. You must be overly generous with reflecting angles and flat mirror sizes. A Berry-style offset and counterbalanced fork on a proper pier would be the most affordable and useful support for a big [amateur] refractor. An adequate, home made equatorial for a 12" should probably have 4" shafts and welded, plate steel bearing housings. Cheap enough, made from scrap materials but incredibly heavy! A steel pier pipe should be the same diameter as the telescope's main tube and supported on a big concrete block foundation. Chimney blocks make useful, tall piers. Or you can take up half the garden with a pyramidal pier constructed from heavy timbers, like mine. Lifting a long OTA [arranged horizontally] is straightforward if you tie two, stabilized ladders together at the top to support a hoist. The height of the ladders must allow more than enough room for the hoist when the OTA has safely reached the mounting. Ask me how I know all of this?

Thanks.

There were supposed to be sunny periods in the morning but there weren't any. Afternoon was a mixture of sun and cloud. Dreadfully soft and agitated seeing. Best I can manage today I'm afraid.

Fascinating! Well done! What is the frame rate for what we are seeing on the forum? I'm trying to get at the reduction ratio of your "slow motion" video. We tend to think of everything "up there" as static. The sun is the most obviously active object we can see.

A handy bucket of rainwater collected from the leaks in the dome. ☔

Thanks. You too. I invested in a full aperture D-ERF. Costly, but worth the peace of mind that I wasn't cooking my '174. The internal D-ERF focused a hot beam just outside the objective. Nasty when it literally set fire to a temporary, cardboard aperture stop.

Well done John and you captured the spicule layer on the limb as well! That's an angry looking spot! The shape reminds me of "Space Invaders."

Congratulations on a nice set of images!

Beautiful Dave! Masses of detail and prodigious scale to boot!

Well done! You've captured loads of detail. You could do a horizontal flip to get the orientation correct: Not a criticism just something to try next time.

You are right Dave. Lots of flares from the complex area to the SE of the main spot. I captured a particularly large and bright flare at 10.48[CET] this morning.

The seeing started soft but improved slowly. This is a later one in B&W and colour. Caught a very bright flare earlier. Sited on the "lumpy bit" of this image.

Don't forget that you have to mount a refractor so you can get under it at high altitudes. Even with a star diagonal you need a tall pier or tall, very sturdy tripod. Though you can sit at a telescope it means your minimum eyepiece height is at eye level [when seated] when the OTA is vertical. Unless you have an adjustable height chair this can mean contortions at different pointing altitudes. My old 6" f/8 on a tall and massive pier on a Fullerscopes MkIV: The 7" thick wall pipe is far too heavy for one person to lift but rock solid.

Sorry, my earlier post may have been a bit too cryptic. I have owned an [already secondhand] 6" f/8 Celestron for many years and never used it without a Fringe Killer for white light. It's upper limit was about 120x on average on the sun [solar foil filtered] and moon and planets. It was used for solar H-a before finally being retired in favour of a shiny new f/10 achromatic objective and DIY tube. My new f/10 iStar objective, in a thin, steel, duct tube, can manage double the old f/8's power on average on the moon and planets. I was shocked to discover I could actually use over 200x routinely on a 6" after many years of being so handicapped. A 6" f/15 [or possibly an f/12 at a push] achromat would make a far better planetary and lunar instrument but is very difficult to mount affordably. An old Fullerscopes MkIV mounting would do if you can find one in fair condition with drives. If you have any DIY skill that would also provide an affordable mounting. A Berry style, counterbalanced plywood fork ALTAZIMUTH would carry any instrument you can physically lift at very low cost. I have no experience of any other make of 6" f/8 but chromatic aberration is function of aperture and focal ratio. You may find this chart useful: Red is VERY BAD. AVOID! Yellow just manageable with specialist filters. Green is better. An APO [or ED] break these rules as well as the bank.

Psst! Anyone want a "little used" Kaleidoscope? Will trade for an f/8!

Thank you John. I may be my own worst critic, but I am often disappointed by much of what I produce in the way of solar images. I must judge my results against those who post online. Much of what I see there totally eclipses my usual standard of image. Only rarely am I pleased with one of my own images. This only ever occurs when I have enjoyed well above average seeing conditions. The image on the monitor is clear, still and sharp during capture. Everything is laid bare as if looking down from a spacecraft. Autostakkert and ImPPG then produce even more fine detail without any real effort on my part. I use my average seeing conditions as countless practice sessions for building experience and hopefully [eventually] some expertise. If it were too easy it wouldn't be worth doing. Or everybody could do it. I don't have ten years of experience to fall back on. So my strategy is to do as much imaging time as possible, as often as possible. Putting in the countless hours as fast as I can. Instead of it being spread over many years. Hopefully I can then "catch up" on those who have imaged only intermittently but over a much longer period. My real handicap is that I shall never have the experience [nor expertise] with sophisticated image handling software. I process my images while I simultaneously capture more videos. Again and again and again while the sun shines.

What do all Lake District astronomers have in common? Trench Feet. I must say that having built an observatory it has absolutely transformed my time spent actually doing real astronomy. Within a few short minutes from making the decision I can be tracking and imaging the sun [or moon.] I often sit there for most of the day if the seeing conditions allow. Or if I'm snapping patiently, between clouds. My wife jokes that I am off to work as I leave for "The Office" in the morning with my laptop case, cameras and filters. I probably enjoy more time imaging in a single day than I did in a whole year before I had the observatory. When I had to work from the ground, outside, surrounded in tall hedges and trees there was a huge psychological hurdle. Lifting heavy refractors onto a mounting, tall enough to need a stepladder, just to close the rings is a thing of the past. Bringing them back down again when they are covered in ice is now just a bad memory. The big imaging monitor is sheltered and in the deep shade of the dome. So no nasty reflections in a tiny, little, laptop screen outside. I am judging the best seeing moments and framing features in a hugely magnified section of a disk, probably four feet, or well over a meter, across. When I have to pause for lunch I can just walk away and come back knowing everything is still set up and running. I can leave an image half processed and it will still be there waiting for me to finish it off. An unexpected shower just needs the shutters to be closed. 10 seconds or less. I turn on the overhead lights and continue processing, blogging, browsing or posting images online.

What do you call a reflector in the Lake District? A rain gauge. What do you call a refractor in the Lake District? A buoyancy device. What do you call a domed observatory in the Lake District? A coracle. 😉

I am frustrated by clear night skies after a whole day of fighting endless cloud for solar imaging.