Rusted

I'll wear a tinfoil pirate hat. Just to be on the safe side.

If the image is too bright then rotating one polarizing filter against another will allow fine adjustment of brightness. Or you can use an ND [Neutral Density] filter. The real question is: Why does the image seem too bright? It shouldn't. Have you used the [wrong type] of photo solar foil instead of the standard visual type? Have you checked the filter for pinholes or damage without the telescope? Just hold it up and use the tiny sun to test the filter as you move it around in front of your face. Any damage will show as local brightening or glare from pinholes. Which solar protection filter film did you use?

For those of us still enjoying this newfangled wireless "thingy" I have discovered the orientation of my laptop matters. End-on to the distant router seems to be favourite for maximum speed on the Ookla straights. GM

I just checked. There is Frederiksberg Astro Society. https://astronomisk.dk/wieth-knudsen-observatoriet/ Astronomisk Selskab - Danmarks landsdækkende forening for astronomi They have a 150mm solar telescope! A real one! https://astronomisk.dk/?p=103 Not like my home made one.

I have no experience of that particular Barlow. As you say, it might be the high powers you are using. The seeing conditions and often the altitude of the object under study are vitally important here. Early morning and sometimes the late afternoon can be steadier. If the object is in sight then. The obvious way to prove it is a good or a poor Barlow is to borrow a different one from somebody. Do you belong to an astro club? That is often a good way to be able to make direct equipment comparisons. Or to have first hand advice on what is good or not so good equipment. Astronomy clubs and societies can be a great way to gain knowledge quickly. There are also Danish astro forums of course. Where people have much more local knowledge of Danish sourced equipment. Mercury is absolutely tiny compared with the sun. So don't expect more than a really tiny, dark blob. My first attempt to capture some pictures of a Mercury transit with a digital camera on my 90mm were poor. NO practice! If you want to capture some good shots of Mercury you need to practice capturing the sun sharply. Do you have a telescope adapter for your Nikon? You may need extension tubes to reach focus. People here can advise. Balancing a heavy camera could be very difficult. Don't take any chances with the equipment toppling and causing damage! I found Venus much easier to see and to photograph in transit because it is so much bigger!

Hej Victor! Det var så lidt. I've just noticed your location. Small world, isn't it? Though I'm only here on loan. Not a real Dane. Do you have a Barlow lens to get higher powers? A star diagonal is good for relaxed viewing too. I find it helps with the floaters. Floaters usually wander slowly across your field of vision. Not really like fixed, fine surface texture. Hopefully you'll have some sunspots to enjoy before very long.

Good job on the filter! I can see surface texture in my 90mm when the power is high enough. So a 3" should be enough. The scale may be even smaller than you imagine. This image is deliberately forced to bring out the surface texture. You wouldn't normally see it like this with the naked eye. But you get an idea for what to look for in scale.

Thanks for the heads up. Anything which inspires the younger generation to get involved in building optical equipment is a plus in my "well thumbed" book.

As an 11-12 year-old I was walking home from school [late 50s, back in the last century] I could see a large black spot on the sun. It was perfectly round and probably abut a 1/4-1/3 of the sun's diameter and remained there throughout the half hour walk. I imagined it must have been a balloon but the distance and time involved suggest it was very unlikely. There was nothing in the papers, nor on the radio, about little green men. Or my parents would certainly have discussed it over dinner. I had the naughty habit of squinting through my fingers at the sun back then. So it may have been a blind spot developing. There is certainly a large difference in the brightness of images seen through each of my eyes. Building my own spectroscopes caused me to look at foolishly bright images too. Not very sensible. I was keen to see all the Fraunhofer lines for myself. And did! In their thousands! A high street optician had 60° prisms on display in the window and I saved up my pocket money for one. I was inspired by Hale's solar work with his tower telescopes and spectrohelioscope which I had discovered in library books. ATM 1, 2 & Advanced have a lot to answer for! It was decades before I could afford a secondhand set of my own. Now what was the question, again?

Do they do one in pink? Takahashitoni [ice cream] anybody? Where's my coat?

Understood. It was a good job you didn't rush out and buy a job lot of baking paper!

sTAlaKtites? I'll get my coat.

It's nice to know that parts of Gravely Blighted are right at the forefront of connectivity.. from ten years ago by other nation's standards. Time to get Google to fly a few bal-Loons over the backwaters?

Baking paper as backing paper. To avoid adhesion. Being a layer deposition system, presumably the base is vitally important to topological accuracy. So baking paper probably isn't flat enough to avoid humps and hollows. It still seem logical, to me at least, that a cheap, sacrificial base layer is used each time. Or at least a base which is tough enough to allow repeated mechanical separation of the printed component. I am probably talking nonsense, as usual, because I haven't really studied the subject of 3D printing. Just reading between the lines.

Is it a vacuum/atmospheric pressure effect which causes the printed object to cling to the glass surface? Why not just use baking paper if it is the print simply sticking to any surface it can adhere to?

It sounds simplistic but I always aim for the sharpest edge [limb] to the disk first. I do this before even hoping for any surface detail or proms in H-a. The surface detail and proms might be slightly away from the sharp edge focus but at least it's a good staring point. Proms might be at a slightly different tuning point to surface detail unless you are very lucky and the tuning points coincide. I've recently found a larger monitor screen [than a typical laptop] is enormously helpful in focusing and seeing fine detail. Practice all this while you have nothing much to see or capture. Do capture some videos and stills and process them in undying hope. Develop a routine and you'll be ready and waiting when there really is something you don't want to miss so you can share your images! My apologies if this all sounds very patronizing. I am a recent convert to H-a solar imaging so it is all still fresh for me too.

Just a couple of points. A wider and longer, fine, flat file is the best way to get flat surfaces. Don't hold the handle. Let the file flatten itself by pressing gently on the middle of the file itself. If the file bridges spaced surfaces it is automatically held flat by both surfaces. A larger, smooth file rides over hollows but still takes downs "the hills." I have made new grub screw holes and threaded them in timing pulley hubs. I usually make three holes for three new screws at 120° apart around the hub. This is easy with a lathe because you can use the 3-jaw chuck to mark the hub. A small sharp tool is run along the hub while suitably tall packing pieces are placed under each chuck jaw in turn. Turn off the power to the lathe beforehand! Three radial screws helps to avoid forcing the pulley off-center. [i.e. Becoming eccentric.] It is important NOT to drill the fresh holes too large for the thread cutting tap. Taps will often cut oversize if you go all the way through. I use paraffin [lamp oil] as a cutting lubricant on aluminium. Stop short of tapping right through and you can arrange the screw to almost bind in the newly threaded hole. This gives you a gentle locking action to avoid the grub screws undoing themselves over time. It would be a disaster if the loosened screws jams or even causes damage to the casting. Particularly if you you had to dismantle the mounting! Blue thread locking fluid might be a good idea. NOT red if you ever want to remove the screws again.

It may not directly help your cause but my laptop wireless connection was crawling and regularly dropping the connection. That is until I moved the laptop out of the radio shadow of the mounting and OTAs. Moving the laptop just 2' [60cm] to the left gave me 100/100Mbps wireless from our 110/110Mbps indoor [fiber] service. My observatory is on the 2nd floor to match the height of the indoor TP-Link wireless router at least 20m away. I read online that it helps to have both router and "receiver" on the same level. My router is sited as close as possible to the outside wall on the same side of the house as the observatory. All this may not directly apply to your situation but it might help others struggling with similar wireless problems. It seems to suggest you should avoid large lumps of metal between you and the indoor router. There are a number of free, online, internet speed checking services. Ookla seems the most prominent but is getting increasingly "noisy" with increased popularity. Using your own ISP's internet speed test is unlikely to be accurate according to my references.

Okay, I'll bite.. what's the red recoil starter handle for?

Some iPhones obviously have a flare for this sort of thing.

According to Stellarium, Venus is well to the left of the Sun at 11.30am from Sofia.

This is a much wider subject than the mere choice of a finder. It relates to the reasons behind the purchase of any and all instruments. I can well understand the purchase of a Takahashi. [Google spelling checker offered Hashish but I didn't inhale.] Convenience, exemplary optical performance. Gob-smacking views with tolerance of very high magnifications. A short OTA is much easier to mount. Wide field of view from being short focus. An investment which holds its value if well protected. That said.. oh dear.. he's off again: Perfect achromatism is to be had from the nastiest, spherical, 3.5", reflector mirror. Very limited aperture. Even if it does bat well above the size of its costly glass. Very high cost. Ian King doesn't even list prices against the models available. Tak doesn't seem to have a monopoly on mechanical excellence. A nice FT focuser is a frequent choice of upgrade. A short F/L needs a very high quality, slow motion focuser more than most. As do any optics with pretensions to quality, of course. Even a humble achromat at f/12!

It would seem my poking gentle fun at the Tak appreciation society has not been appreciated. As can be seen from my own set-up I greatly value function over appearance. Of course that is an entirely personal choice. One based on over half a century of "real world" use. Carrying an ice covered, white elephant in and out of an untidy shed, in the darkness, is not kind to cosmetic finishes. Not protecting the finishes, with the utmost care, will always result in fading, scratches and corrosion over time. Fear of such damage can even become a major hurdle to repeated and regular observation. I would go so far as to say that you should never leave a pretty instrument, or mounting, in an observatory. It will quickly ruin it! Anyway: Doing a quick search for Tak finders suggests that not all users are deliriously happy. I found buyer's reviews where Tak's own screws are blamed for direct damage to the OTA! These users even suggested a complete redesign. Or to buy alternative finder brackets. Harsh criticism indeed from Tak owners! Given the over-emphasis on cosmetic appearance, where Tak is concerned, I would suggest doing your own homework first. Cosmetic damage to an OTA at these elevated price levels is unforgivable and likely to make a severe dent in resale prices. Which is why I would never invest in Tak or AP. I don't want to be responsible for "ruining" a "pretty" telescope. One where appearance is held in such high esteem that it can seriously affect its perceived value. Totally regardless of its completely unchanged, high, optical quality. That said, if anyone has a really battered, 150mm f/10ish AP, with A1 optics, going very cheaply, I might just make an exception. In fact I'd take the lens in its cell and you can keep the original tube for a plant pot support in your drawing room. [Humour alert!]

Just use it at night?

Oh, you mean Vixen green?