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jackrussell0232

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Everything posted by jackrussell0232

  1. Wow, I know I've not been keeping up with the forum, but what a lot of posts on this topic! Everything from sensitivity, noise, stacking, spacing, flats. I love my atik 460, but still bought an 8300 after this (but in this case an SBIG STF8300M). On paper it's a good bit less sensitive, and noisier, but I don't really notice in the end results. What bugs me is the read-out artifacts if you bin 2x2. I can do this on the 460 with no issues, but brighter stars play horrible tricks on the 8300, like a 2 pixel bloom everywhere. So I'll only use it on shorter scopes. I'm sure I'm not the only one with this issue. Please tell me I'm not the only one with this issue!
  2. I'd have to say that if I was looking at a payload of 10-15kg, I'd go for an EQ6-GT (or an EQ6 and belt mod it myself). If I wanted to carry much more, I'm with Olly. Save a bit longer and go for a Mesu. A one-man band is not without its risks in terms of support, but when he shipped a few with a new batch of motors/encoders which turned out to be duff, he drove around the UK himself, fixing or replacing them (I know because mine was one of them). I just wish he'd put an engraved signature on it. Spent many months wrestling with a GM1000, but still have an EQ6 and Mesu in service. Do you really need both scopes on the rig at the same time? Swapping out scopes and re-balancing really doesn't take that long. Does anyone shoot a galaxy one night and a nebula the next? JMHO, Jack
  3. Well, it has been so long since I posted anything........I just had to. Rushed capture, severe lack of processing skill (why is every time like the first time? - try to learn again what you thought you'd grasped when you last did this 3 months ago....) But here's my take on M82. 10x120s Lum, 10x180s R/G/B. 5x900s Ha. Alll bodged together in PI and photoshop. The Ha is really stretched, and it was taken with quite a lot of moon about (any excuse!) But you can see what it is at least. I know I should be doing better, but I'm busy renovating a house (with a nice dark garden - can't wait).
  4. Roy, I've used my Sitech Mesu remotely and found it fine. The level of remote-ness ('remotivity'? [Olly will love that...]) has varied - from 10m away while i sit in my lounge, to 3500 miles, when I've controlled it while I've been away working in California. Occasionally, at first, it did seem to have a mind of its own. Not always parking when asked, and sometimes setting off in the opposite direction to that which I expected. But with the latest version of sitech.exe it seems to be playing. It's in a DIY roll off roof obsy, using a garage door opener to slide the roof, and an IR reflective light switch, which only allows the roof to open and close if the scope is pointing in a specific direction (the reflector is on the back of the ccd camera). I've used it in 'full auto': CCDAP, cloud sensor, sky x, DIY ascom roof driver. Here, it checks for clear sky, opens the roof, plate solves and images etc. But I've also used it in what I call 'virtual remote'. I use windows remote desktop to control the laptop in the Obsy from anywhere, but control it as if I was actually on that laptop in real time. I have a homebrew web relay control box which allows me to turn power on and off to all the peripherals and override the roof. My safety blanket is a webcam in the obsy. So you can watch it all live, and press the stop button if something crazy is happening (and hope the connection doesn't drop out). Does that help?
  5. just lovely, and shows you don't have to get every planned subframe to get a cracking image.
  6. Per, I thought that comment would make you smile. I did look at the focuser and see if it had any play, but it seemed really solid. I tried to adjust the 4 screws, but couldn't set them any tighter without almost locking the drawtube solid. With the spacers I have fitted, the focuser is only extended about 1-2mm. I think the GM1000 model was probably ok, with decent dual-tracking, because the 10 minute subs looked much the same as 10 second ones - but they all had strange shaped stars! I'm hoping to have solved my problems by the time the dark nights return. Ian King has said he will arrange a replacement, but I'm working away from home at the moment, so this won't be for a couple of weeks. I'll let you know how I get on. Jack
  7. What's an 'eyepiece'? Sorry, that would be a Frejval question, but couldn't resist. Having said that, this snag was detected with a ccd - I haven't formally star tested it with an eyepiece yet, as I bought it for imaging only really. Seriously though, thanks Harry. You make me wonder if the tube rings supplied are too tight. I loosened the top halves last night to see if it made any difference and the scope didn't slip when I relaxed my grip on the heavy end, so the bottom sections must have been squeezing it a little? Thoughts? They are a new tube ring type supplied by Ian, made in the UK, not the traditional parallax jobbies.
  8. Thanks for the feedback guys. Although I've seen a few artifacts on different scopes due to cooling and tube currents, I've never seen astigmatism. But I know from my baby Q that the petzval design does some funny things, (like making incorrect reducer to ccd spacing look like field rotation rather than field curvature). It being June and all, I typically only get the roof off at 2230, and the scope has probably reached 25 degrees during the afternoon, but it had had 3 hours to cool by this point (0130), and the temp sensor on the focuser was reading 15C when the temp outside was 13C, so I don't believe this should be thermal. Can the elements really take >3hrs to cool? But I was kind of hoping someone would come back and say, "I had this while the OTA was cooling, but once at equilibrium it was perfect". Or that someone would say "yes I had a tak that did this. I returned it and the replacement was perfect". It really won't do though. The star elongates immediately that perfect focus is lost and grows to an oval with a major diameter around double its focussed size before it starts to go round again. I'm not sure if this is why when I have the bahtinov mask on it and achieve perfect focus, the lines generated by the mask are slightly curved/wiggly, not straight............ They don't wiggle though, which is why I don't think it's tube currents. Looks like I will be testing Ian's patience again. Thanks for the help. Jack
  9. Gents, Ladies, please don't laugh (you can gloat of course), but I'm getting acquainted with a new FSQ106ED. At the same time, I'm testing a GM1000HPS (still...) Odd star shapes have occasionally come with the territory so far with this mount, but I had some very strange results with the 'new Q'. The long and short of this, is that I've discovered that slightly out of focus stars are elongated in one direction, and this direction swings thro 90 degrees when I go from intra to extra focal positions. The fully defocused star images look round enough, but this is really disappointing. I'm just hoping someone can reassure me that this is not normal, and that I should get it replaced rather than just refunded. I know Ian K will look after me, his service is always excellent, just want to make sure it's not just me that thinks this isn't good enough. Any advice welcome, Jack
  10. John, The ccd choice isn't easy I'm afraid, but that's partly because there's some great kit out there. I have an atik 460 and think it's excellent, (low noise and pretty sensitive) but wanted a bigger chip area when I got my FSQ85. My STF8300M is also pretty good (if a bit noisier and less sensitive) but it does have almost twice the area. However, the pixels are a bit bigger, so I find it less well matched to a reduced baby Q. Both of these cameras are very capable performers, but the sensors are small when compared to an 11000 (which unfortunately has even bigger pixels). Unfortunately, a 29050 camera (big area with small pixels) would blow your budget and they're slow to the market. I would definitely sleep soundly buying a takahashi refractor, as expensive as they may appear. Premium optics will always be so. Today's mid range ccd will probably be a paperweight in ten years time. FSQ85 or 106, can't go wrong with either of these. 85 is easier handling, shorter FL and just so so sweet. 106 has a bigger flat field. (Most ED80's are pretty amazing for the money too) Atik 460/490 QSI 660/690 all excellent. QSI 683 is probably the best implementation of the KAF8300 chip. Atik 383 and SBIG STF8300 are both good too if cost is more of a factor. See, not easy is it? Guess this doesn't help much.... Jack
  11. Threads like this always make me smile. Everyone is really giving the same answer, but in an attempt to justify it, or just throw in an extra analogy, it's easy to get something the wrong way round. So here's my attempt to throw myself on my sword and re-write the laws of physics courtesy of a typo or grammatical error. (no digs at anyone intended ). 'Volt drop' along a conductor (power cable) is proportional to the current (I) which flows through it and the resistance ® of said conductor (not applied voltage). This is the V=IR bit. But current is of course proportional to voltage and inversely proportional to the resistance. I = V/R. The power dissipated by the conductor is equal to the voltage drop across it multiplied by the current going through it (P=VI) or V squared/R or I squared x R. This is why the national grid lines convert the voltage from generators up to 400,000 volts to travel the around the country, before transforming it back down to 240v via a series of substations. The send a higher voltage at lower current because this means less electrons flowing (but with much more pressure behind them), so less heating of the cables and less volt drop. Otherwise, the cables would need to be half a metre diameter! A lot of electrickery is just like plumbing (inc kirchoff's), but this practice is quite the opposite - it would be like pumping water from a reservoir through very thin pipe at huge pressure, because it was more efficient. ( Water distribution can use fat pipes because they're hollow and go underground). It is a bit like hydraulics though, where you can develop the same force (deploy huge energy) with very little fluid movement, if it's under huge pressure. High resistance (weedy cable) and high current (motors starting up) are you enemy. Just watch someone trying to jump start a car with comedy jump leads - 100+ amps being drawn means the 12v which the good car battery could supply is all lost across the cables. If your AZ eq is like my old style eq6, it will draw about 3A peak while starting to slew both axes, and this will rapidly drop to just over 1A, but if the 3A surge causes the voltage to drop to 11v, you might have fun and games. This might only need about 0.5 - 0.8 Ohms between all your cables, connectors and everything else and you can't measure that reliably without a specialist milliohmmeter. So if you're running around 10m I'd be tempted to use 2.5mm cable for sure. Phew, is that the longest answer? Bed time for me, exhausted now, Jack
  12. I will try to put some info on my site Roger. I did most of the build while I was in between jobs so to speak, but rushed the roof opener into service before I started going away with my new job. The roof runs on sliding gate track and wheels, which are galvanized steel, but the wooden chassis I used to reinforce the shed absorbs any noise, so it is almost silent in operation. The garage door opener is just a screwfix special, which I think was 180 quid. Will get some pictures soon. Jack
  13. Feel a bit guilty that I've not posted anything about my diy obsy build, but have now got my garage door opener installed and my arduino based controller running. Finally proved the setup by running it while I was away with work recently. Only I could do something so backwards. Out in the californian desert, 50 miles north of mojave, with perfect clear skies - and I'm remotely controlling a scope in lincolnshire, 8 hours ahead of me... Took some time to learn how to speak arduino and ascom driver, but here's a link to to roof sliding open and the scope starting a scripted run: http://www.youtube.com/embed/IudShtvqhvY I hope the link works. Please excuse the polythene sheet, my cats are 'making it their own' Jack
  14. I'm afraid it's all downhill from there. Saturn, that's about as good as it gets in a telescope. I remember getting my wife out of bed at 0300 about twenty years ago, to look at it through a borrowed 3" zeiss refractor. As mad as she was, she forgave me once she'd seen it. 'That's unbelievable' were her very words, 'like someones put a cartoon of saturn just in front of the telescope'. Wouldn't try to wake her now, even for a bright (relatively) galaxy in an eyepiece. I can't see what kit you've used, but more magnification normally means a softer image. So not much point going beyond 150-200x in the uk, even with a posh scope. Maybe on a really still night. Hope this helps, Jack
  15. You're not alone Louise, this happens to everyone. Differential flex between guidescope and imaging scope, or focuser sag (which amounts to the same thing). Dithering, where the next sub starts a bit early, can give you the problem too. I think it's more frustrating for us in the UK, because we know we're unlikely to get another clear night straight after losing one to technical gremlins or just being a biff...(me, always). Chin up, Jack
  16. It's not unusual to see quite a difference between guide traces at the start and end of a night, as the seeing improves and the air cools and settles down. So seeing a difference between days isn't completely unexpected. I've swapped mounts before during the same night, using one at 2200 and another at 0400 and thought 'wow, what an improvement', only to see the second mount mirror the performance of the first at 2200 the following night, and then settle down as less thermal turbulence comes off nearby houses etc. Then I remembered reading something similar in a book 20 years ago... Sometimes the kit does just work better now and then though. Jack
  17. John, Always difficult when you're trying to make a decision as big as this. An ODK 14 is serious dollar, but as a PME, pyxis, OS refractor, QSI ccd and 14" ACF owner, I'm guessing budget is not a major concern. I'm assuming there's more to it than just a change of OTA? If the reduced meade ACF covers the KAF8300 ok then you wouldn't be changing, unless you're looking to move to a 16803 chip or similar. If this is the case then the specs say the ODK would give you more flat field coverage. The OO scopes are supposed to be really good, if you get a good one, but there are still people who end up disappointed with theirs. Pretty sure this won't help, but it is a reply! Jack
  18. I caught these subs last night, 6x20 mins. The wind was not helping, but imaging at 330mm FL on a Mesu takes a lot of the pain out of it. There's only Ha data here, in false-ish colour, as it wasn't grabbing me in black and white (probably because I messed up the processing). I've cut a lot of the stars here with noise and scratch filter, which hasn't given quite the result I was after, but I always find the huge number of stars in this field detracts from the nebula a little. Reduced Baby Q with STF8300, piggy back guided at 160mm with ssag. Hope someone likes it. Criticism always welcome. Jack
  19. Great images, and even better processing than your 'award winner'! Lovely colours, in both interpretations. Jack
  20. Go on Jeffrey, buy the truss RC. Loads of us want to see if they're any good! I'm hoping they've remade the primary mirror support - did you see Rob's 891 with those mirrors in a better chassis? Amazing. With the flat rear plate, if you did get issues with the imaging kit weight distorting the mirror, you could machine a plate to attach the focuser direct to the back of the scope. You've got a great ccd already, and better ones will be out in a few years - for the same money, but this rarely seems to apply to scopes. I have an atik460 and now an STF8300, and although the 694 chip is supposed to be loads more sensitive in theory, in practice it seems only very slightly more efficient (its pixels are slightly bigger of course). No doubt about the noise difference, the sony is loads quieter, but plenty of subs take care of this with an 8300 and you've got more real estate. Maybe if the early reviews are positive FLO might even carry them as their first RCs. Go for it, (and post a review please). Jack
  21. Rob, This is right up there with some of the best images I've seen of this target. I'm sure I'm not alone in thinking that. You'd probably need to be on a mountain in Chile to get much more detail. You should probably include not just subframe durations and totals, but also hours collimating/stripping/modding/rebuilding/collimating/screaming/crying/collimating. Or are you trying not to think about it. I'm pretty sure they fixed Hubble quicker than this. Only joking. Very hard earned this one, and kudos well-deserved. Jack
  22. I bit the bullet and bought the galvanised steel half round track (4x3m lengths) and 6 metal wheels, probably 300 quid all in (ebay). I thought this was expensive, but worth it as one of the key functional components of the build. I've just automated it with a garage door opener and it is almost silent while moving, I was genuinely amazed - no noisier than an EQ6 on max speed. When I ran the wheels along the rails before I assembled everything, I thought 'mmm this might be a bit noisey - metal on metal (brass on steel)', but I guess now it's all mounted, the wooden supports for the rails dampen the sound really well. Wasn't cheap, but before I motorised it, you could easily slide the 8x8 apex roof on and off with an index finger - without straining it. Not sure if this helps, Jack
  23. Cheers for the all positive comments, really appreciate them. Was quite pleased with the detail I managed to get at just 800mm of FL, although it is a decent sized target of course. This was captured and guided using Bisque's the sky X pro, with their camera add on. It really is quite a slick package now, with planetarium, imaging camera, guide cam, scope all integrated. It does plate solving for closed loop goto, dithering and all sorts. I used to use PHD and nebulosity, until dithering was added to the sky X. Think I might be the unluckiest guy ever when it comes to mounts though. I have been tearing my hair out with the GM1000 , I just can't get it to track unguided, even with the baby Q on it (450mm FL) . I've built 25 point models using the sky X platesolve and ascom sync command with no joy, then downloaded maxim and pinpoint to use Per's model builder, but got virtually identical results. I've got a good NTP client running to get accurate time (and GPS on the mount) I've achieved a polar alignment reported within 8 arc seconds, ortho error of 2 arc minutes, exp RMS pointing error of 7 arc secs, but it won't actually point within 10 arc mins, and it drifts typically by approx 4 arcseconds over 10 minutes (RA, and dec if I have dual tracking enabled). The mount is on a fixed pier too. Initially things were made worse by focuser slop, but even with everything tightened up, I'm still no closer to going unguided. Ian King's support via Baader (GE) has been excellent (first mount replaced - no quibbles), but I wish I had the same success that others report. Progress is made even slower because of the limited number of clear nights to test. I was going to put the baby Q back on it, but not sure if the clamshell/foot allows a bit of flex to screw up the model. Did it all just work straight out of the box for you?
  24. James, I have an LX90 SCT, and as a visual/planetary tool, I love it. It was the first serious scope I bought, so I did some basic modded webcam and modded security cam astrophotography with it (10+ years ago). I never managed a subframe longer than 60s, even at f3.3. Eventually I piggy-backed a small refractor on it, and tried imaging through this too, but balancing the set up was quite involved, and there were many other drawbacks, which others have listed. MM is entitled to his opinion, everyone on here is. You can take deep space images with a fork mounted SCT, you can piggy-back a refractor on one - just like someone could have carved the presidents' faces into Mt Rushmore with a screwdriver, don't think it would be much fun though. Using a piggy-backed refractor makes imaging both easier (shorter FL) and more difficult (balance and tracking and autoguiding through an SCT). Good astrophotography is pretty hard already. A number of things can make it very very hard: wrong mount wrong scope (slow or long focal length, or both) insensitive cameras (plus all the environmental stuff - LP, weather...) I would keep the C11 for planetary imaging and visual work. For the price of a good wedge you could get an EQ5. Put a short refractor on this and you'd be good to go, and likely to get plenty of good images. I've seen loads of breathtaking images taken with ED80's on EQ5s. And I've seen plenty of deep sky images taken with SCTs - I just can't remember any of them. JMHO, Jack PS (MM, I do like the look of your wedge though)
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