pete_l

I took up astronomy in 1999 when I lived in the UK. Until then I had never considered nighttime weather, since the forecasts concentrate on what will happen during the day. Therefore I was completely unprepared for the surprise that the UK was mostly cloudy, most of the time. At least: the part (South East) I lived in, was like that. After a time I started to keep a record of when I was able to observe. After discounting cloud-free nights with a bright Moon, nights when I would have to be at work (early) the next morning and times when family / social obligations prevented it, I found I was getting 15-20 sessions per year. Once the equipment was set up, these would typically be a few hours of scope-time. Rarely more than 6 hours and from the beginning or May through to the end of August, very little time at all. During the winter there could be several weeks between sessions, although I did notice that there was frequently a cluster of clear nights during the spring.

Be aware that cotton buds are abrasive. That is why they are useful for cleaning metallic contacts on switches and connectors. Printer paper is another good material for cleaning contacts, because it is abrasive, too. As regards contaminants in water. Hard tap water is unlikely to contain more than 300mg of "stuff" per litre. A single drop of water 1mm³ is one-millionth of a litre. So the maximum amount of minerals in that amount of tap water is 3x10-11 grams In comparison, a single speck of dust is 3000 times larger. Even that amount in tap water is negligible. In deionised water there are typically 100-1000 times less contaminants. So even with that, the amount of impurities are too small to measure. So if used properly and dried-off correctly, any sort of water will leave a mirror or lens free from surface dirt.

I never do and the 20+ year old mirror on my SCT is as clean as when it was new. The secret is to dab, not wipe. And remember the OP is only talking about cleaning a "small splodge" on their mirror. A single cotton bud will be sufficient.

You will not leave any liquid on the mirror after cleaning - you will dry it thoroughly by absorbtion onto a tissue or somesuch. And with no liquid left on the mirror, there will be nothing to evaporate and leave a deposit.

This will require a computerised tracking mount (never cheap!) possibly moving the telescope from your existing setup onto it and also a system for guiding the mount. While many people forget to include the cost of this in their considerations, it is not cheap either. Guiding will need at least another small camera and also a computer / laptop to run the software and control the mount. Plus cabling and power supply. I would suggest having a look on the iceinspace forum. It is Australian and will give you better information about the local costs, vendors and also the second hand market in your country.

You can download the EQ6 manual. It says there that the power supply should be in the range 11 - 16 volts. Your booster should also be able to supply the required current (amps) which the manual also gives limits for. Be aware that just because the car booster says it supplies 16 volts, you should check that under all circumstances it does not exceed that. Personally I would not trust it unless I had looked at the electronics and checked its output voltage myself.

I used them all the time - hundreds of purchases. It must be said, mainly for low-cost electronics items, Arduinos, etc. that can be up to one-tenth of the price: $2 instead of $20 😲 and seem to be just as good as European-sourced stuff (which is almost certainly where they buy from). There are occasional issues, such as receiving a short quantity or getting something that is a long way from what the description said it would be. However, for those few times I have rarely had a problem getting my money returned. I've bought a few astronomical parts there, too. From Svbony, some of the old "analog" LN300 long-exposure cameras (probably my largest single purchase: €70) and telescope / camera adapters that would take a lot of tracking down otherwise.

This new look puts up a new notification (or whatever the jargon of the web software is) for each new post, rather than just listing which threads / topics have new stuff in. See screen capture. This can't be right, it doesn't tell us enough to be useful and is just sending duplicate information that wastes screen space. Is there a way to fix this bug? Or maybe a configuration setting to get back to how it used to be? Example screen capture:

Welcome to the slippery slope! 🤖 There are at least four different sorts of "serial bus" available on an Arduino. All that serial bus means is that data is sent one bit at a time - serially. There are many ways to do that. The two that you have discovered are what is known as I2C which uses 2 Arduino pins and can support many devices, each with its own unique address, on the same 2 wires. The other one you have seen for the DTH11 is a proprietary (and somewhat unreliable) technique used to send a command to a device and then receive a reply back - all on the same single wire, just not at the same time. Apart from these, your future holds an "rs232" talking to (typically) your PC - although the perfectionists will remark that rs232 is much more than just how the bits of a byte are sent down a wire. And SPI that can send/receive bulk data very quickly, for example to draw images or text on an LCD screen. All of these the Arduino can support on different pins at the same time ... if you're lucky.

I think you will find that the room for improvement makes itself apparent, not from the photos you are pleased with but from the ones where you can find things that could be done better, With that in mind I would suggest taking a critical view of the "second division" ones and considering what comes up most often as the gap between great images and not so great ones. It may be that all it needs is a little more experience with the kit you have, rather than gadgets. These ones look great, BTW.

To answer your question, have a look at this website. It will give you some ideas of what is achievable. Your telescope has over twice the aperture of the one on the website, so you should be able to see more than is listed there. 👍 The problem with asking on the internet for advice is that people will generally advise you buy the same things they bought! Even though everyone has a different set of requirements and a different situation regarding the local sky and what they are willing to spend, The flip side is that often they will criticise different suggestions - especially if they think they are a "better" observer than the person asking. I'd suggest remembering the positives and ignoring the negatives. Unless there are many people all giving the same warning about a piece of equipment. One thing I would suggest is that you consider buying a light pollution filter. Otherwise, it sounds like you've done your homework and made a good choice.

I'd suggest giving the RA a bit of a wiggle while the mount is not in use, see if anything moves. It is not unusual for the gear meshing to change with night temperatures and that can be adjusted without dismantling the mount. However, that might not be the problem and gears that are adjusted to optimal in winter can easily bind up when the ambient temperature rises in the summer and the metal expands. I'd also check if any cables are flapping loose. If they move while the mount is tracking, that can present an unexpected load to the motors which can take a little time to correct and then suddenly release. Plastic can stiffen considerably at low temperatures so this may not be obvious if checked at room temperature. Also the same applies to the telescope. check if anything in the optical train is loose or prone to sudden movement.

Looking at the photo, a star seems to move (relative to the camera) from one position to another. The movement looks to be quite rapid as there is very little trailing between the two positions. I assume that the direction of movement is the direction the mount is tracking. The sort of thing that would cause that are a "wobble" in the mount itself or the telescope - something loose. Possibly the gear meshing is not tight enough. Alternatively it could be that a cable is dragging getting caught temporarily or due to stiffness and then "giving" and flipping the position of the telescope to where the motors want it to be.

Well there's your first problem! 😆 Seriously, astro photography bears very little resemblance to normal photography. The most important aspect is that everything you photograph under the night sky will be grossly underexposed. As far as equipment goes, everybody seems to recommend what they have bought, themselves - which isn't much help/ I would suggest starting at this website. Both for a run-down of the principles and also for the equipment reviews they offer. However, the site is USA-centric so much of the stuff available everywhere else doesn't merit a mention. It's also worth knowing that most of the popular / best astronomy equipment is out-of-stock almost everywhere.

Consider this example of M33 and this one as well. Both using the same scope you have, and taken with a DSLR. They both use a focal reducer which has the effect of concentrating the captured light onto fewer pixels in the camera. This makes the object appear brighter but at the expense of having a smaller image. They also both use longer exposure times. This has the effect of allowing more faint detail to be captured, rather than being submerged in the inevitable "noise" as vlaiv says. I realise that with an Alt-Az mount you are limited in your exposure times before the "field rotation" effect starts to smear the stars into ellipses. However another benefit of a focal reducer is that the smaller images allow longer exposures before this happens. So my suggestions would be: get a 0.63 focal reducer. With that, see how long you can expose for before getting squishy stars. Take many more exposures to stack. I would suggest a minimum total exposure time of an hour, but the more you have the better.

Yes. Many of them like to give that impression. Living in "the country" (past the point where Google Maps gives out) and having mains power from overhead cables, we tend to have quite a few outages. Most are only for a few seconds or a few minutes and the UPS that keeps my computers alive can handle that. But anything past 10-15 minutes is getting decidedly dodgy. Recently I put a mains power monitor on the output of the UPS - which is rated at 450 Watts. It shows that the computers and other bits'n'bobs use about 120 Watts. At perfect efficiency, that would require a 10 Amp draw from the bitsy little 7Ah SLA battery in the UPS. Even when it was new, that would be quite an ask.

Something that is worth consideration is differential expansion. When you have a metal - metal connection, both parts will expand in the heat or contract in the cold by roughly the same amount, since they will be made from the same type of metal - aluminium, probably. However, when one part is metal and the other is plastic they might be a good fit at room temperature, but what about when they are 30°C hotter in an observatory during a summer day, or 30°C below room temperature in the night sky in winter. Will they get loose? Will they tighten so much that the plastic cracks? Will the cycling over time cause fractures? I would not like to have £££££'s worth of delicate equipment suspended above a concrete floor just by something like that.

I get the impression that they are intended to compensate for field rotation in Alt-Az set ups. As such they need to track accurately much like an equatorial mount - though only with the weight of the camera attached and possibly not quite down to arc-second accuracy. That would explain their cost. However, for simply framing an image it probably doesn't matter if that sort of rotator only has a resolution of a few degrees. It would be set once at the start of a session so that (for example) a long, thin DSO would be aligned with the long side of a camera. As long as it doesn't slip or have flop that moves the camera while tracking, it wouldn't need the engineering precision of the ones on sale.

Hi Abhishek, It looks like a nice scope you've chosen. You aren't looking for advice on alternatives so I'll stick to answering your request. There is only 1 photo that I could find on Astrobin However the information on Cloudy Nights has one person who can't get their ED140 to work well with their camera. Although they don't have problems with the CEM60, so that looks like it's a suitable mount (though maybe with some additional parts). There is a review of the scope on https://astrobackyard.com/explore-scientific-ed140/ but the person there relies on being given stuff, so the reports are always good. There's three places to look. Good luck

Interesting. Though at the price I was surprised to learn that it did not contain a Raspberry Pi4 2GB. Since the case is more expensive than its contents, I will continue to make do with some cable ties to keep my existing cases in the place where I want them. 🦉

Yes, I have a couple of Pi4's in cases like yours. They are sooooooo much better than the little plastic cases with cheap fans. I run my Pis 24*7 and it is inevitable that after a time the fans become noisy. And when they do 😬 they are noisier than any of my "proper" PCs. So I am a great fan (groan!) of these cases. The only gripe I have is that there is no obvious way to attach the cases to anything - no screw holes, unless you want to use self-tapping screws in between the fins on the heatsink. P.S. did you know that you can attach a SSD to one of the USB3 ports and then (after a software re-config) dump the SD card altogether? You get a vast speed improvement as well as more storage.

Since you only experience vibration when the mount brings your new, longer, heavier, OTA to a stop the quick fix might be to tune the deceleration parameters in your mount controller. So that it slows the slewing speed down before reaching the target. It probably already does that effectively for your SCT. But the greater inertia of the bigger tube would require different accleration / deceleration characteristics. After all, you don't experience any vibrration when the telescope is tracking.

Let's put the "clomping around" issue to the side, as you say it's not that important. Have you positively identified the pier as being the source of vibrations after the mount stops moving the OTA? Most driven mounts have a feature of slowing down and stopping gradually after they have moved most of the way to the target. Does your's do that - I don't recognise the make. If the mount stops suddenly, then I would expect the OTA to "whip" a bit. An effect that would increase significantly with the larger / heavier / longer tube of your Newt. The problem may not be the pillar at all.

As vlaiv says, the Ender 3 series. It seems to be the "EQ6" or Ford Transit of 3D printers When mine arrives (bought from a spanish supplier, been "in delivery" for a month now) I will be able to speak with first-hand knowledge. However I would be wary of trusting equipment to the plastic thread of a 3D printed adapter. Maybe if its payload was light weight and low value and the adapter was not used at low temperatures, it might be OK. A better solution could be to send your design to a professional outfit that would do a metal printed part for you. Though I can't say what engineering tolerances they would guarantee. With luck it would cost less than buying a printer!

The Aliexpress camera in your link says 10 day delivery. I have found that generally they are not too far off that for items they offer with that delivery time. (At least to Spain, it is that quick!) There are other things that I would suggest, based on my experience of setting up a completely different meteor detection camera. First, put much more stuff in the camera enclosure. You do not want the PoE splitter or any ethernet connectors outside "naked" to the elements. They are simply not designed for outside use. Given the enclosure in the article, you could fit the whole shebang, including the RPi in there (without the PoE but with a small router). Though I dislike the idea of running mains voltages outside without "proper" cables designed for the job. Next, the sensitivity of the camera depends massively on the lens used. IME fisheye lenses are a no-go. Their aperture is simply too small for a sensitive set up. Typically they lose the plot with these IP cameras somewhere around Mag. 3 or 4 as the cameras run at 10-30 FPS, no slower. The best lens to use is a F/0.95 lens. They come in 4mm or 6mm focal lengths but do cost more. This camera would be a better option. Be aware that the field of view of this sort of meteor camera is 90° or so. You will not cover the whole sky and you will miss a lot of meteors. That's just physics. I have not used the software from the Global Meteor Network. However, those board cameras need a specific set of configuration parameters to get the best (or any) performance out of them. Those are not the as-delivered defaults. I would guess that the GMN software has a means of configuring the cameras. Otherwise you need to load a windows application that only works with Internet Explorer to set them up. As far as focusing the camera/lens, this really has to be done at night, using a star and before you mount it in some hard-to-reach location . Daytime focus might look OK, but unless you're very lucky it will be quite a way off at night. And an out of focus camera loses a lot of its expensive sensitivity. HTH P.S. To JamesF. The cameras contain firmware that sends an RTSP stream to a host. That software has to catch the incoming frames off the I.P. connection and (presumably) stack them in semi-real time.