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Hmm. I shall have a look at that. Python is very easy so its an attractive option. Wonder if I should stick with ASCOM rather than Alpaca for simplicity but worried anything I do might become redundant in a few years if they are moving away from COM.
Oh well, no excuse then but to use github for the first time and try Visual Studio – which I downloaded years ago and got rid of fairly quickly after I tried to convert a GUI intensive VB6 program to .NET. It wasn’t a happy experience.
Truth be told, a large chunk of my last 10 years has been spent developing software for image processing pretty much in a team of 1. I wrote IDL (or later Python) and its run from command line. My understanding of the ASCOM/Alpaca/Github universe is wafer thin… 🙂
Looks like one of my old laptops is about to be resurrected for this. Be warned, there may be immoderate language…
Does anyone know if theres a latency issue with using Python rather than another language?
Morning Ian,
Thanks for replying. I knew there must be people out there that do this sort of thing but you never get to hear who they are as its a touch niche.
Python sounds great as my progression has been Fortran/Algol/6502/Z80/C/IDL/Python down the decades and I certainly have a spare RPi knocking about…
So, how does it work then? Does it, for every possible taskable type of instruction, issue a command line process calling a Python instance while perhaps storing info in files or environmental variables? I’m intrigued.
I’m fairly certain you can call dlls from Python, so this sounds hopeful.
The ASCOM/Alpaca website said newbies should use their templates – for fear of people picking up bad habits from others – but then failed to say where said templates were. It strikes me as site designed by enthusiasts for other enthusiasts and with way too few examples. Thats said, its a hell of a piece of work.
Sounds rather like a pass of new Starlink satellites.
If you have a look at the Heavens Above website at https://www.heavens-above.com/ you should be able to find out which ones…
This quite good for cloud forecasts too….
https://www.meteoblue.com/en/weather/outdoorsports/seeing/salisbury_united-kingdom_2638664
Yeah, wooden roll off seem less dew laden. I was an occasional user of one thats 10 years old and only now showing need of TLC. I only once encountered water on the scope optics when opening up.
As it happens, I ordered an additional dewheater which arrived yesterday. I will try mounting that down by the mirror cell of my Newtonian and leave it on when not observing. I shall see what happens.
I will also start assembling the RPi bits for a longer term project.
Thanks to everyone for their observations. An alternative view helps.
I think I have to separate the problem into two parts to make it easier to grasp.
During observing: I used to have an AE 10” with thick tube walls and insulating the tube walls certainly seemed to help. The OOUK 12” has much thinner walls on it and so less thermal inertia, so it may not solve the problem entirely but, with a 12” dewheater up by the secondary it may be enough to avoid the faint mistiness on the main mirror I see on some nights. I leave the mirror cell fan running always – drawing a small amount of air down the length of the tube.
During daytime: I’ve been parking the tube inclined upwards at 5 degrees to help the water run off the mirror. I also have both ends open but with a muslin cloth over the end near the eyepiece to catch any smuts from local garden bonfires (it has happened – one of my neighbours went through a pyromaniac phase).
Air is drawn down the tube and out past the main mirror using the small fan in the mirror cell. The rationale was that the mirror front surface would more closely follow the air temperature if the air was moving rather than stagnant. The hope was that any periods of dew would be minimised. That worked badly!
I usually leave a gold coloured accident victim type mylar blanket over the scope to avoid drips from the roof affecting the tube. I tried having a cat blanket underneath the mylar in case that helped, but it didn’t.
I suppose I could increase the fan power or even reverse it so the flow is fast near the mirror and improve heat transfer – but it is heat transfer to the rear of the mirror rather than front. I could put a heater directly behind the fan too… Or even a fan in the tube side (but its a feeble tube anyway and I would rather not weaken it).
Alternatively: I could nearly seal up the tube when not observing and use a Raspberry Pi to monitor the mirror and tube temps (air proxy) with IR sensors and, if need be turn on the heaters and fans accordingly.
An RPi and 12V fan doesn’t use much power and if it worked I could try one of the RPi Zeros instead. I doubt if the heater would be on for long – especially if the tube is insulated. The Rpi would generate a little of its own heat but I have no idea how they cope with sub zero temps.
Has anyone else tried anything like this. What do Planewave and Celestron do with their dew control approaches?
Looks like I need to revisit the power being used.
We had a couple of 2-3C daytime temps followed -4 to-5C nights and now, with a 12C warm, wet front suddenly going through, heres the result….
I’m worrying whether the Pulsar dome is just too damp for C14… The NEQ6 was streaming with water today. I am aware of at least one group I know trying to line a Pulsar dome to stop dripping.
For the record its a 300mm mirror in a 1200mm tube.
Attachments:
I made PV Cep 16.75 (Gaia g unfiltered) on the night of the 2nd.
Picture:https://britastro.org/observations/observation.php?id=20250105_000432_f426e583e7f058d1
I have not yet measured tonight’s images but the activity around the HH region is still going on – its a continuation of what Richard Sargent spotted in November.
Will probably process all my data tomorrow…
A miserable spring and dreadful Oct-Dec here in cloudy Wiltshire…
The number of clear all night instances has been very low.
As space is short in the page limited Handbook, could thought be given to removing pages 117 and 118? Surely its pretty much unchanging from year to year and readily Googled? I think I used the pendulum equation once as a teenager.
Similarly, as a space saving/creating measure, could the line spacing on page 116 be changed? That might free up ~1/3rd page that could be used for some small item like expected dates of observable Earth flyby/gravity assists.
I also wonder who looks at the Bright Stars info page. Genuine question: who uses it?
BTW none of this should be taken as criticism. A huge amount of work must go into creating the Handbook and I for one am very grateful to those who put in the hours. As a result of their work I’ve already started to plan my 2025 observing year. Its good to see the Handbook evolving. Thanks to all involved!
Every time I image an 18th magnitude star for variability or capture a 17th magnitude nebula, I wonder at how things have changed over the last 30 years.
I enjoyed visual observing before neck arthritis stopped play, but these days I get a kick out of what we can do via imaging.
I remember looking at long duration photography in the 80s and thinking I would be really smug if I reached 13th mag with my 8″ Fullerscopes Newtonian and some Tri-X. Its a 1sec exposure with a modern CCD.
