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I’m no engineer, me.
The flame thrower option is now my third resort – and I can console my self with pudding if it fails. Whats not to like?
Apologies. I never think of youtube. I associate it with music mainly. Thanks for the steer.
Yes, the video did make it look easy. Sufficiently so that I now have a second oil filter tool on order – for the price of a pint of beer in London, why not!
Will let you know what transpires.
It had the essential ingredient of being just the right thickness!
Have noticed though that the hot water bottle doesn’t really warm it. Perhaps a blow torch would do better!
Was taking them a few minutes ago. 🙂
Astrobaby suggests a bolt/strap based oil filter wrench, but most of those don’t go down to 58mm diameter. Might try one of the 60mm ones with a few layers of rubber after I try the strap based one arriving tomorrow.
Just a note to say that I have emailed you two images acquired with an old Lodestar and a recently purchased Lodestarx2.
As the cams are uncooled, I kept them in a cold room and then connected each in turn and took darks of 5x 5s duration with each at x1 binning. The noise does look better on the newer Lodestarx2.
I also took the 4th and 2nd frame of the Lodestar sequence and subtracted one from the other and measured the resulting difference image to determine its standard deviation, which was 32.7. Doing the same for the Lodestarx2 gave a standard deviation of 21.1.
I don’t know for a fact that the caps used to block light were equally opaque, but they were the same make. Similarly, the time the cameras had been turned on when each image sequence was taken, probably wasn’t identical. So the CCD may have been at a slightly different temperature as use warmed them up – but it would have been close, a matter of 10s difference at most.
Anyway, hope these are of interest. If anyone else wants copies of the images, then please let me know.
Do let us know what you find about the hotpixels. To me it looks like a factor of 2-3 decrease in the number of hotpixels in the Lodestarx2.
Unfortunately, I saw the same problem a couple of days later. See attached. The corrector plate on the CCD started to cloud from the start. Took it off the scope and indoors to sit nosepiece down on a radiator for an hour…. Not an ideal way to treat kit, but with the first clear night in weeks and no moon I really didn’t want to waste more time than I had already.Later that night there were also hints of condensation inside the corrector plate – so, dew shield now on order. May have to wait ’til a low humidity day and get some air moving through the tube while its in the sun. So, realistically first chance in April?
That’s a nice clean image.
Could we possibly have a higher quality JPG of the section around the centre please. Its difficult to tell if you have an image artefact there or the remainder of the nebula.
Do keep doing the Gyulbudaghian images though, as its always good to see what it is up to!
The constraints are: needs to be operable in a 2.1m dome, plus no more expensive than an 11″ RASA and with at least as much light grasp. I’m using an EQ6Pro, so I know I probably need to upgrade to an EQ8 – though I kind of hanker after a MyT as I have found MEIIs a joy to use, but too damn expensive.
I like the RASA that I occasionally use – a lot. Its given some great wide FOV images, but I’m not really planning to spend all my time going after large sprawling nebulae and find I tend to image smaller objects and so end up cropping the frames hugely. Obviously, a 14″ RASA would be better with more light and a smaller FOV) but they are $12k so thats not happening and it might not even fit anyway
The balance point on open truss systems seems further away from the tube midpoint to me (I could be wrong) and with a 2.1m dome I’ve got to be really careful hence ignoring them at present.
I had the opportunity to use Meade, Celestron and Skywatcher 12″ Dobos next to each other about 10 years ago. None of them gave a less than nice image though, one did excel – I need to go back and find my notes to remember which it was.
A lot of you will of course have bought new telescopes frequently, but for me this is a new experience. I bought an 8″ f8 Fullerscopes second hand in 1985 and a used 10″ AE f4.3 Newt in 2002 and thats my lot, so you can see, the instruments I have used most over the years have been old-school. I did have more ambitious plans but, as always seems to happen, events occurred (chimney in need of a complete rebuild and new car needed) which suck up the spare funds. Probably just as well as a 3m automated dome, Paramount MEII, RASA 14″ and QHY600 would dent the bank account somewhat and cause plaintive wailing from my bank manager.
Thats interesting. I had forgotten the TS scopes. Happily you and someone else have reminded me. I’ve no idea what the quality is like so I shall look into that as I had assumed (erroneously) that they were daft expensive.
I have wondered about the 300PDS from Skywatcher. The focuser is a bit heavy (I used a 130mm version a few years ago) as I recall but given I only have a 2.1m dome to work with, that may work in my favour in countering the mirror weight… The Quattro isn’t bad in that respect.
The PowerNewts are worth knowing about – I imagine collimation could be fun. Thanks
Thats nice to know. I bought a copy for work several years ago and Willmann-Bell were massively disinterested and unhelpful when I said I needed to use the code on an air gapped machine. They never solved the problem and just stopped answering emails.
Some very good books, but not good at customer relations.
Perhaps some of the books will end up on print services.
Thanks for the reply. I had wondered how much better sigma clipping might be. Looks easy enough to implement.
I have wondered if the skewness of the sample pixels could be calculated and that used as a threshold for pixel removal – though I suspect that might be more computationally intensive than sigma clip.
I shall have a play on some data I’m working on.
One minor tweak….
You say that you need the outer annulus mean value and standard deviation. But, in cluttered fields, does using the median value help protect you from outliers?
I did my first variable star measurement in 30 years.
Result: 20201009 01:27 Mag=14.1 (first crude estimate using AAVSO) while AA7 says 13.94. What does everyone else use?
Refined result using Gaia DR2 plus another from the following night…
20201009 01:27 2459131.60262 14.05
20201010 00:21 2459132.51466 14.30
Managed to catch it around midnight during a brief clear very transparent slot following the swirl of cloud that caused such heavy rain yesterday afternoon. The coldest night of the autumn here so far. Was 4C by the time I closed down – must bring the geraniums indoors.
It really is very faint isn’t it? When the other lobe of the nebula is the brighter of the two then you know its dim.
The faintest I received in our study – August 2009 – was 18.75, so we’re in unexplored territory.
Am kind of hoping it ends up repeating the cycle we observed, so we can say its got an 11 to 12 year cycle, but thats probably too much to hope for. 🙂
