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Mr Jack, it cannot be, I cannot believe such a ‘discovery’. Basically, almost, domes and telescope only need painting and lubrication. Now that’s a real treasure, other than the one in Louis Stevenson’s novel. I say this because in my association (the former Associazione Astrofili Abruzzesi) things went a little differently: we had built a Newtonian D300 mm F1500 mm. A beautiful telescope equipped with a D100 mm apo astrograph dedicated to the search for asteroids, in collaboration with the state observatory of Collurania (in the town of Teramo).
The instrument was placed on an old medieval tower, Torre De Sterlich, 10 km from our city Pescara in Central Italy. The 20-metre high tower and telescope are in the attached pictures.
One evening, we went there for an observation and found that the telescope had been catapulted from the top of the tower with all its accessories. Astrograph, push-button motors, eyepieces, blackboard and everything else lay on the ground at the foot of the tower. Everything had been destroyed by unknown vandals.
Thus ended the Association.
Any comments are yours.
In any case, congratulations on the preservation of things.Translated with DeepL.com (free version)
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Due to my unfortunately very limited knowledge of English, I may not have understood what the actual problem is. However, I dare to say that I have solved to a large extent the cause of my ever-painful neck-breaks and twisting after coming to frame with my NIKON D3000, by sticking a small prism on a frame with silicone, which I attach to the camera’s viewfinder. Certainly not the best, nor is it ‘Columbus egg’. I just avoided a perhaps unnecessary expense, like so many others that amateur astronomers make.
If I have not understood what the underlying problem is, please excuse me.
Greetings to allTranslated with DeepL.com (free version)
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If I understood correctly, I would say that the travel of the eyepiece holder tube, i.e. the focuser, is too short for the diverter (prism or mirror) not to be inserted. It is obvious that without a diverter, the focal plane remains very far out in relation to the extrusion of the eyepiece holder tube. I have the same problem with a Russian telescope. That is if I have not misunderstood.
Saluti
GiovanniHello everyone
your conversation has piqued my interest. A few months ago I devoted myself, for a while, to meteoric observation. Exactly, not to the photographic or visual capture of meteor strips, but to the detection of stratospheric dust caused by impacting meteors. For this I have taken my cue from the following article.https://journals.ametsoc.org/view/journals/atot/25/9/2008jtecha1090_1.xml
I will not elaborate, I will only say that I have only partially succeeded. The main flaw was the way of acquiring the detected brightness values with a telephoto lens D100 mm f500. In fact I wrote down by hand the values returned by a photocell (taken from an old Zenith camera). In short, I have abandoned the intentions; however, I return to that idea from time to time.
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Engineer Robert, thank you for your consideration of my request. Yes, indeed the long interval marked by many studies (theoretical and experimental) of lunar mineralogy, but without any reference to the phenomenon I have recalled, raises uncertainty in my simple studies of lunar eclipse photometry. I have photometric observations of eclipses for more than an entire solar cycle, and it seems very strange that such a conspicuous phenomenon does not generate interest.
Dear Arditti
You are absolutely right (‘unfortunately’)!
Therefore, the mere thought of limiting this welter of lights, better orienting many stupidly pointed headlights, adjusting this skylight that seems to be emitted, diffused, flowing without any consideration from a Dantesque bedlam; limiting waste, in the dark seeing better and more but paying less would be a misleading option: his fretus! Based on this fine conclusion we will continue to have more and more poisoned air, light pollution and starless skies.
I enclose a frame of the situation of my sky to the SSE, from my current residence at an altitude of 700m. This will be named ‘Capital of Culture 2026’.But tell me: is it worth spending money to buy a new telescope?
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Good morning to all. Concerning the effects of light pollution, i.e. lights that make the sky bright at night, perhaps these two recent articles will be of interest.
1] Mazzoleni E. et al. Outdoor artificial light at night and risk of early-onset dementia: a case-control study in the Modena population, northern Italy. Heliyon 9, 7, luglio 2023: e17837. 2023. https://doi.org/10.1016/j.heliyon.2023.e17837
2] Voigt R.M. et a.l Outdoor Night time Light Exposure (Light Pollution) is Associated with Alzheimer’s Disease,.. Frontiers in Neuroscience, 18, 6 September 2024 https://doi.org/10.3389/fnins.2024.1378498
It is a great pleasure to be acquainted (even if only epistolary) with a person who knows a lot about the subject matter of one’s passion. Many congratulations to Dr Andy
This is the exit phase.
I am a mess and I don’t remember when the phenomenon occurred; if I am not mistaken it was a few years ago. For this levity of mine, please excuse me.Greetings again.
I would say that despite the bad weather the footage is well done. The clip illustrates the event reasonably well. The focus is well placed. Attached is a previous Saturn occultation and an image taken with Registax5 from the related clip taken with a Tou cam Pro webcam at the focus of a MAK90+Barlow3x.
We hope to have good skies for the partial lunar eclipse, which will be on 18 September. I am very interested in lunar eclipses, I have been observing for over 15 years. If someone could make an observation we would agree on the procedure.Thank you and greetings to all.
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It went badly, no observation. Overcast sky throughout the night. The clouds begin to thin out an hour before the initial phase. The moon always remains covered by a small cloud. On the way out, the sky was already blue but a persistent small cloud also prohibited visual observation. The picture shows the best situation.
The sky mocked me.
I hope it went well for you.Attachments:
Please excuse me, I confused with another image. The observatory is left out does not appear, at the bottom of the picture is the historic Campo Imperatore hotel.
I wish you all a good and beautiful observation.
I planned to observe the event by taking the telescope to an altitude of 2500m on Mount Aquila in the Gran Sasso d’Italia. Unfortunately, the weather forecast is not favourable. Here in the valley (L’Aquila city) it has been thunderstorms and hail for a few days, and on the high peaks even worse. I will stay on the terrace at home, God send me good luck.Pictured is the panorama from the summit of Monte Aquila. Below, the two domes of the Abruzzo astronomical observatory (at an altitude of 2120 m)
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Yes, I have still verified that for large ranges of brightness, ordinary cameras are not very suitable. I am currently in the process of making a photometer with a photocell applied to the focus of a telephoto lens (really bad optics) with a diameter of 110 mm. However, the quality of the image matters little as I only need to measure the illuminance. I don’t remember if I mentioned that my programme is concomitant with the Perseid shower. It is a job that should be a novelty in the amateur field. Thank you Peter.
Greetings to all the friends who have listened to me and to whom I may have annoyed a little: the passion for Urania is strong.Translated with DeepL.com (free version)
Peter, thank you for your interest in my question. Yes, indeed everything is looking quite difficult, and as I would need to collect a lot of numerical data for my purpose, I have started to abandon the idea of proceeding with a chamber. I have just finished an observation conducted with a photoelectric cell placed on the focal plane of a telephoto lens. Everything seems to be much simpler. The only annoyance is having to write down the measured potential differences by hand, which if misread are no longer retrievable.
Everything is done in preparation for observing the Perseids. That is why I have also developed a theory on which I base my observations and process the collected data.Translated with DeepL.com (free version)
I learn this news with heartfelt regret. Meade has allowed me to do many things at reasonable prices.
The market for amateur telescopes and their accessories appears to be out of date. Telescope companies are suffocating themselves, especially as the stars have disappeared from the sky. The various online marketplaces as they are filled with gear (everything has become ballast) of all kinds still new put up for sale because they are superfluous. A few days ago, I took a Celestron D90mm refractor to one of the flea markets in my town. The manager didn’t want it, he said it wasn’t for sale. He only agreed to try because we have known each other for years.
In my country they say: only after you have bought it do you realise that you don’t need it.Translated with DeepL.com (free version)
Peter, yes Active D-Lighting is switched off.
Grant, that’s my problem, I don’t understand.
All I need is to set up a plan for observing the brightness of the sky at sunset and sunrise. Anyway, I have already started trying using the jpg format. The first results are quite satisfactory. We will talk about this as soon as they are available.Hello
Dear colleagues, there is another small (small so to speak) problem. The attached graph shows the pixel values of images of the usual white sheet, taken with a nikon D3000 camera and varying only the shutter speed. A few things emerge:
1 – the maximum PV value, corresponding to the minimum shutter speed, is 255. As if I had shot in jpg format;
2 – there is no proportionality between PV and shutter speed. The function is completely different from the one in Robin’s graph;
3 – the PV-lens surface graph is almost linear at each iso.
The sensor of the nikon is of the CCD type.I would ask for help in interpreting these at least apparent inconsistencies.
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Nick, please excuse me for not mentioning your intervention. It only appeared after the new graph was posted. Maybe it’s my PC showing signs of old age. I saw one of the links, it is a bit difficult for me, I will have to study it. Thank you.
Grant and Paul, you are very kind, I am not an expert in the soft stuff, however I will follow what you tell me tomorrow. I just hope I don’t do any damage to my system.
However, I see that the problem is not limited only to the jpg format I use, which gives little information. Certainly there remains the problem of reducing the PVs at the same shooting time. I enclose another graph that I constructed just today. In it, the PVs are shown as a function of the lens area (abscissa at the bottom) and the relative aperture ratio shown at the top, and for various ISOs. It is comforting that there is proportionality between PV variations for a given number of ISOs. It is certain then that PVs are a function of at least 2 variables: ISO and shutter speed. The mathematical function seems to be quite difficult to handle. I am looking for a good way to find it and then handle it as easily as possible.Attachments:
