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Showing content with the highest reputation on 05/05/19 in all areas

  1. 10 points
    Last night I popped out around 11pm to my "usual" local spot on the coast. As I got out of the car i noticed that the house with the session wrecking security light had it switched off, and wow, the sky was looking good overhead and to the south. There are low horizons all round with the beach/sea to the south. It was like being in a snow globe that had been shook The LP domes from towns to the east and west were not as bad as they often are - transparency was decent. I threw up the scope, popped in a 10E, and first target was M51. Wow. I wasn't even dark adapted, but there it was, big and swirly. Spiral arms obvious with averted vision, as was the bridge. I returned to it several times over the next hour, and as my eyes adapted, I could see beautiful knotty spiral structure with direct vision with a 17E, with teeny foreground stars sprinkled and superimposed on the arms. I could have packed up and gone home happy with just that one familiar target that I've visited so many times. I think I skipped M101 for some reason, had a quick look at the Owl neb, then went down to M64 (nice view of the black eye feature). I saw IC3483 and Zwicky's Virgo triplet, NGC4568 (Siamese Twins), M99 (Coma Pinwheel, teasing that structure was on the brink of averted visibility, but not giving up its secrets). With the 10E I hit the Needle, NGC4565 - big and impressive, with the dust lane in averted vision. Then I paid a visit to M87, and on up to Makarians Chain - with the 10E, just panning around I more often use a N31T5 here - on one hand stunning to take in all the galaxies in one fov, but very rewarding to get in closer and explore. Next up was the Mini Sombrero NGC 5746. A new one for me, a lovely dust lane, well worth a visit. Then the streak that is the Silver Needle NGC 4244. I then went to test transparency on M81/82. First with the 10E on M81: big, hints of sweeping structure. Panned over to M82 - wow, the size, brightness and mottling with the 10E. Switched to the 17E and yep, could better see the sweep of the two arms in M81, to the extent of one pointing towards M82, and the other away from it. I once saw fine leading edges on these from my back garden, but not last night. My hands were really frozen at this point and I took a last look at the Cats eye, with a 6E - very bright and green blue, central star, but I didn't see the internal structure I've seen before - but I didn't attach my O-III last night. Very happy I went out: only an hour and a half, not fully dark adapted but saw lots from a local spot that is decent but not very dark. The views of M51 will stay with me
  2. 5 points
    My first effort at Sol for a while and in spite of the clouds and the wobbly seeing I did manage a few short vids of AR2740.
  3. 5 points
    It is not often in the UK that we have a bank holiday weekend, a new moon and a clear sky at the same time. Last night was one of those rare occasions! The forecast (Clear Outside) was not very definitive about the cloud cover, but from looking at the satellite images and from experience, I thought this could be a magnificent sky as we were on the backside of the last weather front. So, I thought – let’s give it a go, we could be rewarded. By 9pm the car was packed with the C8 and my trusty Vixen SP-DX. A quick check on my friend Steve, and yes, he was up for it, too. Steve is a beginner, so I offered to show him some of the objects I am familiar with and should give a decent view under good conditions. I also wanted to see some of the fainter galaxies which populate the spring skies. The spot we were planning on using is in Southern Cambridgeshire – and compared to light polluted London and St Albans, this looks like “Deep-Sky-Country”, although it actually isn’t perfect. It’s the improvement from the home conditions that count! On the way, I cranked up the aircon to maximum (lowest temp) to pre-cool the scope. This was going to be a chilly night… Arrived at the spot just after 10pm, Steve parked up five minutes later. Thankfully the wind that had battered the South East the whole day had eased off and the remnants of daytime clouds soon hurried to disappear. I spent some time building up the scope and polar aligning while the last bits of twilight disappeared. The sky was now fully dark and really quite impressive considering how close to London this place still is. To the South the capital’s light dome stretched to about 20° above the horizon. Cambridge cast its lights in the North-East although to a much lesser degree. The spring constellations were up to the South with Leo having passed the meridian and the plough right above us in the zenith. We started the evening with a simple target to warm up – M3. A delightful sparkle of stars filled the eyepiece. With the 15mm LV (133x) the core was starting to be resolved - the telescope was not completely cooled down yet, but this was indeed a good starter to the night indeed. Next, we changed direction and pointed at M51, which clearly showed the two galaxy nuclei and the surrounding disc of haziness with direct vision. No spiral structure visible (but that wasn’t really expected with 8” anyway). The pair was nicely framed in the 30mm NLVW (68x) with a foreground star in NGC5194 clearly discernible. As spring is galaxy season we pushed the scope over to Denebola in Leo to go hunting for members of the Virgo cluster. We started with M98, which was a fuzzy faint blob and a bit disappointing. Next object was M99, which was much more pronounced although without any detail in the 30mm. Over to M84 and the starting point of Markarian’s chain. Using the 40mm Celestron Axiom eyepiece (70° afov) four galaxies were immediately visible. There was a bright one in the bottom of the view (M84), with a slightly bigger one in the centre (M86) and a pair of two distinct but faint galaxies to the top (NGC4435/38). Slewing along a bit further, NGC4458 became visible. An incredible sight, especially if you imagine how many millions of light years these are away from us and how big these objects are! We did not follow the rest of the chain (have to revisit this again!), but instead decided to look at something brighter. M81/82 were right over head and simply amazing. Directly viewed, both fit into the eyepiece at 50x magnification (40mm Axiom). M81 clearly an elongated, lens shaped disc. M82 showed as a thick streak of light. Ramping up the magnification to 133x (15mm LV), it revealed its knotted structure with direct vision! It has been a long time since I had seen M82 this clearly. The sky was indeed rather good! To get a bit of variety, I moved the scope to the owl (M97). In went the Lumicon OIII Filter. In the 15mm LV, the sky background turned into an inky black with the stars taking on a slightly reddish colour. The nebula stood out like it was cut out of cardboard! While gazing at it for a little while longer, we were able to see some texture inside the “disc” of the nebula – hints of the owl eyes. As the filter was in, we decided look at another planetary – M57 the ring in Lyra. About 50° above the horizon, a clear ring shape with a dark interior was visible against a black sky (thanks to the filter) - beautifully defined and clear! Next up was M13, the great Hercules globular cluster and it was sparkling with the lights of millions of suns. An extremely contrasty view, resolved into the core… Suddenly we realised some clouds had started to appear, coming in from the North and beginning to cover parts of the North-Eastern sky. So we changed direction (yet again), to look at more galaxies. The whale (NGC4631) was faint, but clearly defined in shape, really resembling a maritime. Unfortunately, we did not look out for NGC 4627, the whale’s companion. NGC4656 – the hockey stick, was faintly visible with averted vision, but no clear shape discernible. NGC4565 – the Needle was starting to get blocked out by a thin layer of high clouds at around 11.45pm. A slightly disappointing sight. By this time, the finder had already dewed up and the first patched of haze were forming on the corrector plate of the C8. The sky was now also covered over more and more, so we decided to end the evening at this point. We packed everything back into the car in about 20mins and drove off at around 12.15. While driving I noticed my feet were actually deep frozen already! The car showed a temperature of just 4°C, no wonder it felt chilly. Thankfully the wind had not picked up all night. Overall a wonderful session with many old favourites and some new additions as well as some targets left over for the next galaxy season. Have to revisit Markarian again and scan the full extent, also missed the black eye and sombrero galaxies this time. Let’s hope for more clear skies soon!
  4. 4 points
    Hello there, In order to get a good feeling of what it’s like to do some stargazing from a labeled dark sky reserve area, some members of our local astronomy club have spent a full week in Saint-André-Capcèze, Lozère district, right between Villefort and Génolhac), at the guesthouse « Au Portaou » (www.au-portaou.com). Since the owners of this guesthouse can speak fluently English, German, Dutch and French (she’s from Belgium, he is from Germany) please have a look and feel free to go there a week or a couple of days, you will be impressed by the sky quality, and pleased by the warm welcoming B&B. As for the sky, we had not seen such a dark sky, nor this level of seeing since our trip to Chile last year, amazing. Because of the weather conditions, not every night was fully successful, but still, we had a fantastic week. The area where we have settled the scopes has a South, South-East orientation, and we had way enough space for 5 scopes, including 2 dobsonians of 400mm and 2 of 250mm. Full darkness was achieved thanks to the total absence of any artificial light, no street lamp, no parasite light bulbs of any kind, nothing... only The city of Alès, 40 to 50km south, could bring a faint light halo on the horizon. SQM was definitely and consistently over 21, easily. We had to use our head torches in order to walk around since we could not see each other’s in the dark, almost scary ? !! We are no longer used to this level of darkness, especially at our usual spots. In the middle of the night, the Milky Way had arisen enough to see it from one side of the valley to the other side, completely, gorgeous with a lot of contrast. Personally, I had never seen so many details in M101, I could keep on magnifying and pushing on M53, and had never seen so much contrast on M92 or simply on M3. In total, I observed a list of about 40 objects, from tight doubles to the brightest Messier’s, and of course many galaxies from the NGC catalog in Virgo or Coma B in this season. All in all, a fantastic sky, very clear and transparent, with a good seeing, and barely no light pollution (only this Alès halo, very faint). In the guesthouse, every single attention of the owners was making us feel like VIP guests : old and well restored house, excellent food from Patricia, the owner, Hans, her husband made some space in a small cellar so that we could store our chairs and gears during the day, etc... I totally recommend this place and this area. If only light pollution was down to this level all over France, especially in the North East where I live ! For sure we will go there again next year !
  5. 3 points
    Heres the new AR today, seeing here is fazey again but good when its in focus. theres some lovely proms too if you get chance for a look. heres a qwick snap of the AR. Clear skys all. charl.
  6. 3 points
    c80 ed 450d moded. 20x300 sec,20 flats,20 bias.
  7. 3 points
    I found this data on my hard drive-I never processed more than the Ha due to only having 4 OIII subs. I decided to give it another try, hoping that my processing had improved to the point where I could get something passable out of it. I lost some FOV due to poor framing, and the OIII subs could only be calibrated with a master dark--the flats were lost with my external hard drive. TOA 130 with .7x reducer and STT 8300 with 3nm Astrodon filters Ha: 9 30 min OIII: 4 30 min
  8. 2 points
    A 4" ED refractor will be far more versatile than a 5" Mak, as it will give you the wide field views a SCT or Mak Cass can't. A 4" ED like Stu suggested above would be a perfect complement to your 8" SCT. Another option may be a second hand SW 120ED, yet it is still easily transportable and doesn't need a heavy mount. The ED refractor will also have the added advantage of being truly sharp with great definition and very high contrast.
  9. 2 points
    An after lunch image:
  10. 2 points
    Captured image from shortly before dawn this morning at the time of the ISS passover. Just visible in the SE. Sun 05 May 2019 03:22:07 BST
  11. 2 points
    Hey all, Lots of clouds this morning and only ok seeing, but managed to get a little bit of AR2740 and the proms around it. It seems to have thrown some lovely surge proms later, but I'm clouded out for those. This was around 0930am Eastern when I captured these. Captured in HA, WL & CaK at various scales to compare as seeing allowed. Saw a little tiny flare activity around the spot. B&W: Colored: Equipment: C8 Edge + Aires Tri-Band D-ERF + Baader 2" UV/IR Block Filter *Daystar Quark Chromosphere + 0.5x Focal Reducer + IMX174 (HA, F21) *Baader 610nm Long Pass + Baader 6 stop ND + 2x Barlow + IMX174 (WL, F20) ST80 @ 80mm F5 + Baader 2" UV/IR Block Filter *Daystar Quark Chromosphere + IMX174 (HA, F21) ST80 @ 40mm F10 + Baader 2" UV/IR Block Filter (Full Disc HA) Daystar Quark Chromosphere + 0.5x Focal Reducer + IMX174 (HA, F21) ST80 @ 40mm F10 + Baader Blue CCD-IR Block Filter (Full Disc, CaK) Skybender + 395nm Block Filter + PST Cak Filter + Chroma 393 1A Filter + IMX178 (CaK, F10) Very best,
  12. 2 points
    Actually, you'd need to take the Newtonian completely apart, for a proper job. Ah, but no more ghosts and goblins within the field-of-view. When observing an object, the contrast would be noticeably improved, to see its details more clearly, and the background sky surrounding the object would be blacker, instead of just grey-black. Have a look at what I did to my own... https://stargazerslounge.com/topic/262096-deadening-a-150mm-f5-newtonian/ Any questions? I'd be glad to help.
  13. 1 point
    I would like this topic to raise the profile and awareness for using a Sky Quality Meter aimed at dark sky seeking, DSO observers. A sky quality meter, is a hand held device that reads in magnitude per square arc second, night sky brightness. A popular model, and one that I use myself, is a Unihedron SQM-L. This device has an angular sensitivity response of 42 degrees, which is used to take readings at zenith and can also be used to aim at other angles towards an intended target. Observers using this device will take a frequency of readings throughout an observing period, when transparency is good and will log the lowest, highest and average reading. A SQM is also handy to make comparisons if you travel to varied sites. A few years ago, when I made the decision that travel to explore varied dark sky locations was to be my primary aim as a visual astronomy, I purchased a Unihedron Sky Quality Meter from FLO. The first time I took it out, I had been at the time a member of a regional astro society and attended their dark sky site. I was so pre-occupied that it never occurred to me, that is until I'd packed up, to take a reading with my new meter. Following this I made a conscious effort to ensure that taking readings was to be integral to a dark sky session, yet even then it was still almost an after thought late on in the session. However this was to change as gradually I began to place value and priority upon taking a frequency of readings intermittently during the course of the night. It steadily occurred to me that much of my time at a dark sky location was actually occupied just looking up, becoming increasing dark adapted and taking SQM readings. Each of my dark sky trips has to be within an hours drive, perhaps a little more, from home, as factoring in the return journey is essential. There are many locations to explore and I have discovered some quite special places gained within this time frame. For each though, there are still light domes, to get away from this scourge will involve traveling further, deeper. On a recent backpacking, wild camp trip in the Cheviots, Northumberland, I took along my trusty, compact SQM. Unfortunately, whilst there was a great sunset, transparency deteriorated somewhat and it was not required (though great views were had of Jupiter, Venus Moon). My plan for the autumn is to go, further and deeper, wild camping and taking with me my Sky Quality Meter. I do not have aperture fever, what I do have is a strong desire to experience gaining high quality dark sky places and take along what ever optical equipment I am able to carry. Observing in the UK is challenging as the night sky fades and diminishes due to excessive lighting and constant pressures for development. The Green Belt is severely under threat, villages are being transformed into small Towns. Valuing our pockets of sky quality is crucial and measuring, recording on here in reports helpful. One final point, there are on-line map resources that convey magnitude readings for any location. This might be useful as a very general guide, but is as far as I am concerned highly inaccurate and ought not be quoted and included in reports, or other forum accounts. For example I like to go stargazing in the Breamish Valley in Northumberland. The map reading for this location is 21.84 mag, my own readings have never improved - so far, at just over 21.5, it may be slightly darker deeper within the valley but the map reading is still an exaggeration. It will be interesting to learn if you use a SQM or intend to use one.
  14. 1 point
    The space dragon seems to have eaten the bottom corner, was that intentional? The rest is fantastic!
  15. 1 point
    We really do like causality, don't we? Dang, if we lost causality we'd take another hit to our egos. Copernicus was bad enough then Harlow Shapely made it even worse. For a moment it looked as if that nice Edwin Hubble had put us back in the middle of the action but then Einstein knocked that one on the head. But maybe, just maybe, there is no such thing as causality... ?lly
  16. 1 point
    I use my wife’s old hairdryer, it works wonders, clears the dew in a few seconds. But at x Kw it does require a mains lead out to wherever you’re working...
  17. 1 point
    Great job Paul, the DSLR and 80ED is a great combination. I was tempted to try this myself but didn’t get a chance as session was cut short.
  18. 1 point
    Lovely shot, Danny! where is this spot Danny? I was over on Llandewyn Island yesterday and I could see several of the peaks in Snowdonia had snow on them. In fact, as I was driving north-west though Cheshire, the Clywydian Range in the distance was also white. Were you up amongst the snow?
  19. 1 point
    Thanks all for the help but I think I may have solved it. I figured that (barring a cabling or mechanical fault) there should only be a limited number of things that could be wrong. The most obvious was the location data which I now get from a GPS dongle (having cocked it up enough previously) so that was fine. Then I wondered if EQMOD was assuming the wrong date/time. I couldn't see why but I did notice that it was misinterpreting both the date and time from the GPS, although this had never happened before. I removed the GPS from the equation, rebooted everything and had exactly the same problem. As a last resort before taking a hammer to the whole kit I searched for where EQMOD keeps its configuration file. In the file I found an entry "TimeDelta=-7168" and figured it must be wrong as I'm UK based and therefore GMT. I set the value to zero and did the whole restart everything bit and it works! Now to ponder what I've learned from all this after missing easily the best viewing night of the year so far last night. Thanks again for all the help.
  20. 1 point
    Here is a reliable star hopping route to M81 and M82 - thanks to Stu on this forum for pointing this one out to me
  21. 1 point
    If I was buying complementary scope I would get a fast refractor for low power wide field views. I think even achromat would do, since it is mostly higher powers where CA becomes a problem. Probably something around 100mm f/6 with 2" focuser.
  22. 1 point
    Hello there. Where abouts are you planning to go camping then?
  23. 1 point
  24. 1 point
    Quite right, as you want to have experience with the telescope and its workings beforehand. It was a year of observing before I began my own. You would be without the telescope during the renovation, of course, but then you'd have the improved views of which to look forward once it's completed. In addition to the flocking, I use matte, chalkboard-black spray paint, and I sometimes spray the paint into a condiment lid or other and apply the paint with artists' brushes, when applicable. Within my link posted previously, I later abandoned the idea of flocking the drawtube of the focusser. Its interior might need to be repainted however, if desired, and upon inspection. The "black" paints used by the manufacturers are nowhere near the blackest available. The goal is to make the front entry and the entire interior of the telescope up to the eyepiece as inhospitable to stray reflections of light as possible. If I had to go back in time, and before my own was performed, I wouldn't observe with it until after I did it all over again.
  25. 1 point
    Thanks Dan. You don't have to send a pic, you have more room between the scope and the dovetail for the bolt than I do. I can put a spacer or something. Thanks again Kurt
  26. 1 point
  27. 1 point
    Might be struggling, but that spot's showing some definition
  28. 1 point
    I've spent a good few times giving up after not being able to find M3 and M81. I'm better now (usually) but they are not easy star hops. I recommend trying something nearer a bright star and also something not up right near the zenith. My finder is backwards and upside down and it took me a lot of practice to improve and I still double check what the telescope tube is doing to make sure. The Great Cluster in Hercules might be good to practice on (although it's beaten me a few times). Experience will tell you how bright a bright star will look in your finder. Sometimes I mistake a dimmer star for the one I want. Good luck.
  29. 1 point
    No it's not a wide FOV from the guide camera, I just mean to say that it's quite a bit larger than the FOV from your main scope / camera.
  30. 1 point
    I can really feel your frustration @Fieldsy!!! I think that you're exactly right that the problem is how many different learning curves you can end up ascending at the same time. Can I suggest you drop the guiding just for the moment. Perhaps target clusters which can give you great images from relatively short exposures and use this to really sort out imaging with your main camera? Then you can get some reward for your efforts.
  31. 1 point
    Ok, so how are you going about it? Are you star hopping or just placing the finderscope where you think the target should be? Also, is your finder a straight through or RACI type? Knowing this really helps know which way to move the scope. With a straight through one I find keeping both eyes open can help when you are trying to out the scope on a brighter star, as they line up in both eyes when you are in target. There is a good star hop to M81/M82 which you might find useful, attached here. Keep at it, once you get the hang of it you will find it easy.
  32. 1 point
    ps. Just visited your blog and read of your tales of woe on CdC. Glad I'm not the only one
  33. 1 point
    I seem to recall when I was using phd1 for this I had to select server in one of the menus in PHD. Carole
  34. 1 point
    The thing about darks is, to be effective, they need to be taken with the chip at the same temperature as the lights. This is a combination of ambient (air) temperature and the energy being released as heat during the imaging process. With a cooled camera, you can determine the temperature of the chip precisely, whenever you take the darks, and so they can be done anytime. With a DSLR you do not have that option (normally) and so they need to be taken at the same time as the lights to get them as closely matching as possible. Badly matching darks are worse than no darks at all. For short exposures, it is easy enough to cover the scope and run off a set of 10-20 darks at the time. For longer exposures (>60s) it can start to eat into prime imaging time!
  35. 1 point
    You're winning! ? Olly
  36. 1 point
    Amazing detail you've got there. Thanks for giving sunshine to those in cloud
  37. 1 point
    Very portable ? The breakdown time of the scope, needing a reasonable size vehicle to fit everything in without damaging anything(even with a truss). Setting up time when your at site, re collimation of the scope at the site. Then the same when packing away and when set up at home again. I would not say 16" very portable. For a 16inch scope yes it was highly portable, it broke down into 3 sections and the heaviest was the base that housed the main mirror but still liftable on your own and was setup and taken down very swiftly.. Its not my scope, didn't need a airfare as it was already on the island of Gran Canaria.. check out Astro tours GC if you're visiting, worth a look just for the dark skies
  38. 1 point
    The only thing I did to the first image I posted was mask off the nebula and use a pixel math formula that removes “mottling” in background. It works pretty well. The I dropped the black point just a bit because the pixel math formula tends to lighten the background (kind of normalizes it so it can get a bit brighter)
  39. 1 point
    I promise you that there is a world of difference between a dedicated mono camera and a 1000D having owned a cooled 1000D for imaging. The dark current and read noise are much higher and its only getting 30% QE or maybe even worse at 650nm. I assume that again as per the OP you are not going for a cooled camera due to cost. If that is the case then I really do recommend a mono sensor at the very least. Personally if I was going to get a 183 mono without cooling then it would be the Altair Hypercam 183m as it has some advantages over the ASI, binning 2x2 would be a good idea. Without cooling you will need to take temperature matched dark frames on the same night as your imaging run. The ASI 294mc is at the top end of sensitivity for OSC cameras, but due to its dark current would really need to be cooled. Adam
  40. 1 point
    If the ED glass type is not specified it's best to assume FP-51 or an equivalent. My experience is that manufacturers are very quick to publicise FPL-53 or equivalent glass when its used in an objective. Apart from other things it's quite a lot more expensive than FPL-51 so they want ot promote the fact that it's used to justify the adiitional cost of the scope.
  41. 1 point
    Nicely done Pete. I also wimped out.
  42. 1 point
    Good catch Pete. Grabbed my haul before the weather went south!
  43. 1 point
    Hi, here is last nights shot at M101. This is a luminance run only and was to test to see if the central Halo was still there, and it is, grrrr. I have a sneaky suspicion it is coming from the edge of the secondary mirror. I have pretty much painted everything else matt black, so far. Anyway, Here is the Luminance run. Subs: 10x 300sec, 5x 420sec Processed in Pixinsight. BIAS, DARKS and FLATS applied. Cheers Paul
  44. 1 point
    I have owned both 5nm Astrodon filters and Baader filters. Both have good quality AR coatings with the AD filters being a little better and a little narrower, but the baaders are still good, with almost all other filters I have heard of issues with reflections to one extent or another. For me the 5nm ADs I currently own are not really that much better than 6nm or 7nm filters in terms of band pass, its all about the AR coatings.
  45. 1 point
    Well, I have the ASC installed on the north side of the observatory though not everything is working yet. I've connected up the dew heater and camera cooling and running the cooling water circulation. I have yet to connect the focus motor and the pressurisation system. I may get some of that done this evening but now I'm going to get myself some food. Meanwhile, here's the first image with the new version and a photo of the installation.
  46. 1 point
  47. 1 point
    A 10 inch triplet with flourite glass and folded configuration. An unusual design It's for sale for 34,000 Euros if any one is interested - not my sale, needless to say
  48. 1 point
    Very nice...Those ovals are indeed looking good and also well captured, thanks Avani...
  49. 1 point
    There are other perspectives here - e.g. that of the R&D engineering team who have to develop telescope mounts and their control electronics, and that of the business owners who have to pay for the R&D and the manufactured products and business overheads from sales of rather esoteric and very modestly priced equipment, judged against the standards of other kit mentioned in this thread, e.g. smartphones. Unpick this a little: 1. Most astro kit is developed and manufactured in China these days, by engineers with a hands-on outlook, supported by consultants in specific specialties. These suppliers are focused on cost leadership rather than performance leadership, and they target the volume end of the market rather than the high value/highly engineered end. There is no useful market in top-of-the-line mounts or telescopes - that is closer to handcrafting than organised mass manufacture. There is also little real innovation, which is understandable given the demographics of the user base. Consequently, you will not commonly find 'nice-to-have' but non-essential features that require significant engineering development to make reliable, such as sophisticated real-time mount error and refraction modelling, sophisticated GUI's, programmable PPEC, engineering test and diagnostic routines etc. These require meaty motion controller firmware stacks and fast hardware capable of multi-threaded refined trajectory calculation, motion input summing, high speed axis encoder decoding etc. This costs a lot of money and time to develop, for a target audience that will be generally unengaged by the complexities of getting it to work, and unwilling to pay a price sufficient to cover the R&D and ongoing support costs. Consider too the size of the global market for 50kg payload weight class GEM's and above. It is very small indeed. On the other hand, there are tens of thousands of quite basic, light-duty, cast aluminium, dodgy worm gear driven mounts sold annually with 8 bit microontroller user interface paddles and cheap Allegro-based microstepping GoTo motor drives. Think of the Christmas trade in the West, department store telescopes aimed at childrearing, and the cutthroat pricing that applies to that. This addresses an undiscriminating volume market. 2. After more than 3 decades in engineering one of the constant themes I see is lack of respect for engineering development by non-engineers. Bringing mount location, UTC, altitude, air temperature, mount axis position and other relevant use parameters onboard from either inbuilt or auxiliary devices like smartphones, to the required accuracy and with acceptable reliability, so that Goto can be completely automated and accurate is not simple and not cheap to do. And, to cap that, the market still values antidiluvian mount geometries like the GEM, decades after professional users have abandoned it for more rational and higher performance alternatives. 3. Look at unrelated specialist fields for what is done there. How about 'premium cars' - an increasingly meaningless term once one delves beneath the superficial. Telematics systems provided are invariably several years behind the state of the art, and invariably far less capable and ergonomic than the smartphone-based alternatives. Meaningful failure diagnostics and condition monitoring is never offered to end-users, never mind real-time powertrain optimisation and other functions. The fundamental reason for this seems to be that the business model of mainstream automotive OEM's is based in part on maintaining information barriers to end-users in order to generate revenues from repair costs outside the warranty period. (Tesla seem to be changing that. But Tesla is a market-maker and an evangelist...) The hot take here, is that is unreasonable to demand that astro equipment mount makers 'reach for the stars' technologically-speaking when we see little evidence that in other consumer fields, whether automotive, consumtronics, medical devices, domestic durable goods etc this is prioritised. The key ways to get suppliers to offer better more capable products is: 1. to assiduously develop a more discerning market, through special interest discussion forums such as this one, and 2. to encourage greater collaborative development of equipment between manufacturer and end-user. 802.11 Wifi modules with serial interfaces cost a few bucls and are easy to program. GPS modules and chips are very cheap. If these things really matter, either the end-user community need to engineer their own retrofits for popular mounts, or market premium pricing in favour of products with these attributes needs to be communicated convincingly to manufacturers.
  50. 1 point
    I was given one by a very kind guest and use it regularly. It's useful for an imager because we are constantly losing our adaptation thanks to our computer screens, so it is very hard to make a meaningful check on the sky visually. Since my home is also my dark site I can comment on the variations seen in the SQM. On what we call 'clear nights' our readings vary considerably, between 21.4 and 22. Below 21.4 you generally think it looks a bit hazy. To distinguish between 21.5 and 22 I think you'd need to have some reference test stars since a casual upward gaze doesn't tell you much. This suggests that you need to make a number of readings at the same site in order to build up a real picture of its quality. Sometimes I have the feeling that the transparency is mediocre when I step outside and am pleasantly surprised when the SQM says it's actually good. This impression never works the other way round. I never think it's good when it isn't. I used to have a collection of remembered test stars for estimating the transparency but my sight has degenerated so much that I can't see half of the blessèd things on a perfect night these days. Such is life! Olly
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