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m000c400

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About m000c400

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    Nebula

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    Cambridge
  1. Thanks... In fact where I fly is also shown ;-) I'm sort of lucky as I'm walking distance to Gransden Lodge, so I've got easy access to a safe, flat open and relatively dark site ( for the south of England ).. with a bar, mains electricity and internet, but how many times do you think I've done it? Just once!! This set was inspired by reading a few sites detailing some more 'exotic' deep sky object to try for. Once I was inspired and with some pictures taken it's a case of comparing with published pictures and 'star hopping' your image to work out which smudge is the one you are after. I did try that myself once.... But after a few goes I eventually decided that it was a bit of a stretch for a SW150, but that was a few years back, and I'd like to think I have got better since then... so maybe I should try again!!
  2. I managed it with 14's. You can just about fit a 14, pullys, belts and a control system in the standard housing which makes a very neat solution My quick write up is here https://stargazerslounge.com/topic/261153-another-eq5-upgrade-project/
  3. Recently I refreshed my old EQ3 for wide fielding. Although I had a previous version going on the EQ3, and have done a custom PCB version for my EQ5 I took a few moments to see what was new. The board below is about 7cm x 6cm and takes an Arduino Nano and 3 stepsticks ( Obviously you only need to populate 2). It seems to sell from about a fiver on the worlds favourite auction site( depending on how long you want to wait) but makes a very quick, no soldering, almost "off the shelf" solution. I couldn't find a nice case, but my 3D printer sorted that for me. The only real weakness is the low max stepping rates on 16Mhz processors, but mine is for wide field so the I can afford to step quite slowly. Search ebay for "cnc shield v4" if you are interested. I took a few moments to make my software fully configurable, so now supports a whole spectrum of options and cpu types. One day I may even "finish" it, but we all know that day will never come!!!
  4. m000c400

    Milkyway

  5. I think 15 for the first and 16 for the second
  6. Hi All, Attached are a couple of pictures from a few nights ago that I though were interesting to share. These come from my folder of "Show your mates/wife/husband, tell them what it is, watch it compute for quite a while and then say .. whoooooow" The first is Quasar APM 08279+5255 The little marked smudge appears to be a long way away by any standards. I haven't quite got my head round cosmological distances, but in the pub the phrases "26.. Billion.. Light Years", "Edge of the observable universe" and "beginning of time?" seems to make it all go quiet for a bit. More details here. After this I moved on to another similar object. Another Quasar, but as you can see in the inset, a figure of 8 shape. This is because it is two views of the same object caused by gravitational lensing by a galaxy between us and the object. again more details here Equipment used was relatively modest, SW150p on EQ5 with a home made Goto, plus a 'pre-loved' Nikon D5100. Both pictures are from roughly 10x5min exposures and both are currently well placed in the sky if anyone else fancies a go. These may not be the most technically impressive, but I think they are the most thought provoking images I've taken so far. After these I moved onto 5 hours on M101..... and that was a complete blurry, noisy, grey rubbish mess, and has all gone in the digital bin. But overall a good night Mike
  7. m000c400

    Quasars

  8. I've been having lots of fun over the pas two seasons with my EQ3 project, but I secretly knew it was a bit sticky and not really man enough for the job. So in about September, when I stumbled across a 'graded stock' EQ5 at about 1/2 price Paypal got exercised quite quickly. At first it was going to be a , 'just move the existing motors and controllers across' project, but as is always the case I realised I could 'make it better by just.......' and eventually it became a bit more of a project. I quickly realised that if I spent a bit more time and upfront design effort, I could squeeze the whole lot into the existing motor housing, and after what has been quite a few months of fiddling it finally made it outside over the last few evenings. On the left is a standard 5x2.1mm power jack. On the right a USB connection and connector for the DEC motor. The RA motor, pulleys and belts etc, plus all the control electronics are in that standard plastic housing. Inside started out as basic strip board, but in the end because it is so cheap and easy these days , I did a very basic custom PCB Computing power is provided by a super cheap STM32 module. These are a bit like the popular Adruino boards, but require a little more experience to get up and running. On the plus side, they are a 32 bit processor running at 70-80Mhz, so there is about 4-5 times the horsepower available. Thanks to the current craze for 3D printers and the like, there are some nice stepper motor modules around now. So I've put two standard sockets in, and finally settled on some slightly more expensive ones, as the cheapest ones you can buy aren't quite as good as they sound. The last 'I could just..' was to modify my software to support two ( simultaneous if required ) ports and squeeze a Bluetooth module inside (not shown). In theory (although only tested indoors so far) you can plonk the mount down and attach a 12V battery and that is it for connectors and wires.... I also have a tiny USB2 hub on the mount, so the 'full' setup ( guide camera, DSLR, interalometer, etc) only requires the addition of a a single USB cable The performance last night was much better than my old system, but not without some room for fettling and tinkering, I might even take some pictures...Thanks for looking, Mike
  9. After the children went to bed last night I set up my kit up on the patio. As as the forecast was very clear I decided to leave it out all night... When I woke up this morning I was so impressed with this I had to share it. Now I know others take more impressive shots, however I'm using a simple SW150p ( ie not even the fancy DS version) on a manual EQ3-2, but with a home made dual axis motors and controller system. My camera is a "spares or repair" Nikon DX40 (from a popular auction site) that I removed all the IR filters from and cost me £40, plus a whole lot of other home made & DIY kit do do everything else you need (you should be getting the idea by now...) Image is from 59x300s with other correction frames from my library.Full image is here http://www.astrobin.com/160090/0/ I love how the dust is beginning to show, as I never thought I'd be able to capture that with such basic kit. Thanks for looking
  10. Thanks for posting that. I can see the difference when compared with your posting a few days ago. I'm not so depressed at how poor my efforts were last night, when compared to my better attempts. Mike
  11. This quote above is very important. You really need to understand its implications before going further or you could really confuse yourself. A the fact that you using an "accumulating square top" sample rather than an ideal delta to sample with adds a pretty aggressive spatial LPF to the incoming signal before it is sampled. In the 1D signal world, imagine the difference between a low pass track and hold before conversion and a straight instant conversion. (1D signal processing and 2D image processing work with exactly the same maths, That's what makes math such a light weigh and useful tool box to have ) This is such a big effect you have to include it in your thinking before deciding if you have a problem. Also, frequencies sampled below the Nyquist rate are not randomly re-distributed. They "fold back" at the Nyquist frequency. So if you sample at Fs, and have a signal at (Fs/2) +n, it will appear after sampling at (Fs/2)-n. So if the problem exists it should be fairly easy to locate it. Mike
  12. Yes, that's it for the RA axis. The motor for the DEC axis is tucked round the corner so needs a MXL belt drive. This has a very modest 30:18 ratio on it solely because that was the sweet spot of pulley sizes and belts that were in stock at the time I ordered. You can see it all here, which reminds me to tidy up those last few wires...
  13. Hi, I went "radical" from the start. I wanted to be able to leave the hand slow-motion controls in place so I could still jump out into the garden and set up in <10 seconds when the children say "Hey Jupiter is visible, can we look". But I also still had an eye to eventually wanting very fine control. To square these two, I bought the highest torque NMEA 17 motors I could find (ebay is teeming with them), and have them on "direct drive", with no gear box. With the power off, you can still use the hand controls like normal, but because the available motor torque is so high with power on, I can microstep down far further than the usual x16 that people tend to use ( I can set upto x128 ) and get the same sort of resolution as a traditional geared design. So I have something that now covers everything from hand controls to sub arc-second GOTO all in a single package.. the best of all worlds . Like the others have said, start simple. My first go was just the RA axis on a fixed sidereal speed. Nothing helps you make progress more than a few simple succsses, and nothing slows you down more than something complex that doesn't work Based on you idea above I ordered my IR handset and receiver earlier. A whole £1.80, although I expect delivery from China could be slow.....
  14. As other have said this is very do-able these days, and with all the Arduino and Arduino-like prototyping stuff around (both hardware and software) you can pretty much do it by assembling off the shelf components; both in hardware and software, and just do the "glue" your self. My own "project" is pretty much as you describe, starting with a vanilla EQ2-3, but I've implemented a full GOTO system; once you start this isn't much more difficult. But, your IR control is an interesting idea that I hadn't though of. A quick look shows that there are quite a few TV like IR remotes plus receivers around for "pocket money". So this bit would be easy to do too. In fact based on this I think I'll add this feature to mine over the next few weeks. A pocket size remote seems a lot more practical in the dark muddy back garden that my current solution... a good idea!! Mike
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