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StuartJPP

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StuartJPP last won the day on December 18 2017

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  • Gender
    Male
  • Interests
    Birding and now a bit of astrophotography.
  • Location
    Leeds, UK

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  1. A very good question....do the northern lights look anything like this to the unaided naked eye even under the most spectacular conditions (as advertised by Icelandic cruises)? Considering this is how Andromeda is portrayed: But we all know what the Andromeda galaxy looks like to the naked eye. I haven't witnessed northern lights myself*....so I can't comment but I am surprised at how few comparisons are made between photos and how the show looked to the naked eye on a particular night (there's one or two on Google search). I can comment on noctilucent clouds and the photos and the naked eye visualisation can be quite similar with the naked eye being a bit more faint but still very impressive and easily seen with the mk1 eyeball during a spectacular show. *I think I once did witness a faint showing of the NL but I didn't even take photos as I wasn't even really aware of them, just thought it was thin cloud. Someone I knew staying about 3 miles away from where I was staying took some fairly impressive looking NL images that night.....🤷‍♂️ Thanks to the impressive photos above which I would never claim to be my own.
  2. Thanks chaps unfortunately they are not removable, well not without any major surgery so that's why I was contemplating some form of front filter(s) that could be added and removed quickly. I think I'd basically be adding a pair of glasses to the front of the bins to correct for hyperopia and need a prescription of the correct diopter. I think the issue comes in that fractional positive dioptre filters are not very common. I can't believe that there isn't a set available for exactly this type of application though it's obvious I don't really know what I'm talking about 😂
  3. Not sure if this is the right place to put this but I'm sure someone here will know way more about it than me. What I am trying to do is reduce the minimum focusing distance of my binoculars (8x42) so that I can focus on objects closer than say 2 meters. I'm not bothered that I will lose infinity focus at this point as it would only be temporary should the opportunity call for it. In the photography world I can attach a close-up filter to my camera lens and it will allow me to focus the lens closer and closer depending on what diopter filter I attach. I have tried one or two different ones that I already own (+1 or +2) but it shifts the minimum focusing distance from about 5 meters to about 20cm, way too close. I have read somewhere that I'd need a +0.25 diopter or even +0.125 or less to perform this function.....is this correct? Where on earth can I get such a filter in the size of the objective of the bins? Probably in the days gone by I could have had an optician grind one but not even sure this is something plausible these days. It seems like every genre of optics, photography, astronomy, microscopy etc. has its own vernacular despite the underlying physics being the same thing.
  4. I'll take them both onboard @vlaiv and @AstroKeith as I'm sure they both play a part in it. Of course this thread (that I missed) may also play a big part in it. I equate my experience to looking at those washed out LCD monitors of yesteryear where there was no real black and the contrast was poor.
  5. I was out last Saturday night imaging from my usual spot and although the SQM meter was indicating pretty much the same as usual (circa 20.80) things just didn't seem very dark at all to the naked eye. Conditions weren't perfect as there was a slight bit of haze but no worse than what I'm used to. I could make out the cloud of the Milky Way but again it just didn't seem very bright, almost washed out like someone has been adjusting the contrast/gamma. What has changed is that the street lights have changed from sodium vapour to LED so could it be more of a perception thing? Also I was using different imaging kit to usual so I couldn't compare previous subs to this session to see if it was better or worse. I thought that an SQM reading would go lower as the sky fog/glow increased but as I said it was pretty much where it usually is. Any thoughts? PS...one other thing that has changed is that I'm getting older but I'd have thought that would make the view dimmer not brighter 😂
  6. I missed the conclusion to this, glad to see you are up and running again Ash. I'm always in favour of getting the most out of any device and save it from landfill.
  7. You won't be loving it when it is unscheduled and part of daily life, just ask any South African. Don't worry, you'll be able to process the images when the power eventually returns, if it's on long enough to actually finish processing them before it's off again that is. While it's off you can sort out the freezer of spoiled food and charge up your power banks.
  8. On that specific star it looks like the same issue as this to me. However the rest of the field looks pretty free from the same artefact (though the other dimmer star not far away and close to the edge appears to be starting to have the same issue). It is the brightest star and is at the fringes so maybe the mirror box or something else is causing an obstruction?
  9. Okay, who are you and what have you done with the real Olly? 😜
  10. Hi Ash, Yes the stripe marking on the capacitor does have to be facing the same direction as in my photo. That's important. The solder you have is fine, it has 5 cores of flux in it.
  11. Hi Ash, do you have any solder at all? The vast majority of solder has flux infused. You may be able to get away without using it if not but I doubt you will get a decent solder joint. Would probably be okay to check if that is the only thing wrong. Just remember to get the polarity of the capacitor right otherwise it will all have been in vain. Fingers crossed it was just that capacitor. Without a multimeter it's not going to be easy to do much more fault finding. If I were you I'd get one, just a cheapie, always comes in handy.
  12. Hi Ash, Do you have a multimeter handy? It would be useful to measure across the capacitor in continuity/Ohms mode to confirm that it is a short, then remove the capacitor and measure again to see if it has gone. Definitely make sure you're not powering up with anything more than 12V. Can also use a 100uF capacitor as well if they are available. If possible check to see if you can get a 25V capacitor instead of a 16V one, might help going forwards though obviously in the same footprint and height. I'll have a look in my "bits" box and see what I've got but I don't think I've got many tantalum capacitors at all. If I do I could pop one or two in the post. If there was space, other types of capacitors could have been used but it is quite a tight fit in there and I doubt you'd get the top lid back on with anything more bulky.
  13. Hi Ash, Finally managed to get a photo of the PCB. Looks like the capacitor that was damaged is a 47uF, 16V surface mount tantalum capacitor. The fact that it is rated at 16V doesn't leave much room for margin if the unit was powered from anything other than 12V DC. Power is fed through an "idiot" diode coming from the 8 pin header so incorrect polarity shouldn't have been an issue. Was the unit plugged into something and using the guiding port (the RJ-45 connector) at all? That could have been another path for things to have gone wrong. The stepper motor is controlled by the Allegro A3984 using a tangential pulse speed that changes over time depending on how far away the head is from the start position to achieve the tracking accuracy. I did some investigations a long time ago on how it all works.
  14. Looks like a tantalum capacitor. They do have a tendency to go wrong spontaneously and in doing so normally go short circuit. I can pop the cover off mine to see what value it should be if you're considering repairing it? Depending on where it is in the circuit it may be sacrificial and protected the rest of the circuit, fingers crossed.
  15. Depends on how thick the Pritt layer is but it tends to melt away anyway. I wouldn't say It is as smooth as on the original glass, but certainly better than not sticking.
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