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LouisJB

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Everything posted by LouisJB

  1. I've had one a while - I like it. The camera itself is great, I use it as a guider or as a planetary camera. however the drivers are what let it down. Being windoze only and being a bit sketchy at times I've found this is the side that is a let down. Still, it does work and it's a good price so for that I can recommend (with reservations above) - there's not a massive amount of choice in that area for that price so unless you want to spend a lot more, it's a pretty good buy...
  2. Some great pictures here, impressive. Even more so for the cost of this tube. I started with a 130P (non-pds) which I thought was pin-sharp image wise, then jumped to a 200 (GSO) - while I love it and visually it's great, for imaging it can be a bit of a lump sometimes. I'm thinking to compliment it with a smaller PDS for imaging, that will also be able to use all my existing accessories, the mpcc etc My question is, 130PDS or 150PDS, probably it makes sense to go 130PDS and go wider, to compliment the 200. Right?
  3. Seems the Sun is quite active at the moment, interesting BBC article on the Sun: http://www.bbc.co.uk/news/science-environment-27406358 As I recall the peak was around 2013 so I guess it's just about gone through the solar maximum and will be pretty active but decaying over the new few years
  4. thanks everyone. Just a single shot, in JPEG :s - was a bit grab and go and I've not had a chance to use the scope lately and so was all fingers and thumbs. Took a while to get the camera remote working. Was surprised at the number of spots and the detail on the surface, it looked a bit 'angry' compared to when I last looked some months ago. The difference the BST explorer 12mm made over the stock 10mm Skywatcher + going from 650 to 1000mm native focal length made quite a different to what you can actually see on the surface, I was quite pleased really. Solar scope... will be mine, one day The Moon is up tonight isn't it, tempting to take a look at that too.
  5. Hi, The Sun looked very active today, lots of spots. Took a snap, doesn't really do it justice compared to the amazing image I got through the 12mm BST eyepiece I used. However, I left the camera on JPEG - Doh, so perhaps better luck next time... I don't have any special equipment for Solar photography but maybe a solar scope will get added to the Christmas list.
  6. Hello and welcome. Whereabouts are you in South Cali? Some great skies out that way, I remember stopping to look at the Milky way one night somewhere in Arizona / California near Death Valley and being literally amazed at what could be seen.
  7. I feel the pain. Since getting a new OTA in december it's been out maybe 3 times, perhaps it was 4, but that was 2 months ago nearly. Last year before the rain came I was out all the time, could even pick and choose. When will it end!
  8. no, not really, that's one of the big unknowns really. There are some things that are candidates for them, but nothing to account for all of it. it might be it doesn't really exist and actually our best theories are wrong... we "think" they are different because they must have distinct properties, one like matter causing gravitational contraction and the other like energy causing outward pressure
  9. not sure that's really quite right. There are two distinct types of dark stuff. Dark energy is thought to be the primary cause of expansion. Expansion affects everything (dark or otherwise, but some things are tightly bound so don't get affected). Dark matter is matter i.e. something with mass obeying gravity (but maybe _not_ baryonic) that is needed to account for the characteristics of matter seen at large scales like galaxies, where we see rotation not exactly in-line with what you can explain by gravity and the visible matter we can observe alone.
  10. well that's what gravitationally bound is, galaxies close enough together will feel force of gravity due to their masses that will keep them from drifting apart. Similarly even stronger forces keep atoms bound and sub-atomic particles bound, so the expansion happens but things with stronger binding force don't get ripped apart or stretched directly. Why is there expansion - well that goes back to things like dark energy and so on as discussed earlier in the topic. In the beginning (so some interpretation of the big-bang theory says) everything was driven apart by pressure, pressure caused by extreme temperatures and radiation pressure which literally caused a big explosion. Now much later that sort of driving force is not dominant. Gravity is the main player at large cosmic scales even though it's by far the weakest force. Since gravity is so weak and current theory (a theory attempting to explain accelerating expansion) suggests some constant repulsive force is pushing things apart at the large scale (not you or I or the solar system or galaxy etc). Some sources of this include vacuum energy (which can actually be seen/measured) and some unknown other energy (like dark energy) - but the exact nature of these things is not known (so we don't really know if these ideas are correct). Some of this was sort of discussed at the start of the thread in response to the OPs questions. There's quite a few aspects to consider really, more than a few words here can really do justice to. Out of all the things it's worth reiterating two important concepts. 1: expanding universe does not imply more "stuff" is being created 2: expansion due to dark energy etc is thought to be constant i.e. same amount per cubic meter today as when the universe was just 1 cubic meter, or any time in-between or in the future. You can see from this intrinsic property of energy in space that it becomes dominant as time progresses, matter gets less dense and there are vastly more cubic meters for repulsive energy to come from. Hope that helps a bit. There's many ways to interpret this stuff and undoubtedly things will change as more discoveries are made. That's the thing, we keep asking and observing/experimenting and gradually more properties of the universe are uncovered...
  11. right so you can take the lens out of the barlow and use it as a t to 1.25" adapter. Only use it as an actual barlow on planets/Moon and very bright stuff. Nebula are generally dim and very big, the last thing you want is to barlow it. Take lots of subs up to the exposure length limit where you start to see trails and then stack them, I've seen some great results with logs of very short exposures stacked. If it's a P (not PDS) then you might not get prime focus, I couldn't with mine and my APS-C DSLR (Pentax K5). In that case a barlow (with lens) can be used temporarily (as it shifts the focal point back out of the draw-tube) and more correctly you can move the primary mirror cell up the tube with longer bolts. As with all these things you'll probably need to try it to see what works and what does not. But don't barlow DSOs and faint stuff, that will increase your exposure time (for a 2x barlow, 4x exposure times needed!) and unless you have a guided EQ mount that can guide indefinitely (which you don't) then you want to get the most photons captured per second of exposure...
  12. wow that's really neutralised the gradient effectively. The lack of data captured probably means there's not enough to distinguish background gradient from image, but I could see this working well with stronger data. Will you make it slightly adjustable so it can be tweaked, perhaps there's a compromise between ensuring no data is lost and having a slight background gradient in cases like this. Good work anyway, do keep us posted on updates etc
  13. Hi, sorry missed there was more activity on this thread. I think it's best to think about c, the speed of light as a limit for velocity that can't be crossed (or even reached for anything with rest mass). The expansion of the universe is not really speed or velocity, it is a stretching of the fabric. Two points far enough on the fabric can be (apparently) moving due to this stretching at a rate at or faster than light without contradicting Einstein's relativity and the limits on local velocity limited by the speed of light. What it means though is. a) there's a limit on what part of the universe we can see. Centred on us (or any observer in fact in any location) imagine a sphere that is the observable universe, you can see to the edge of the sphere that represents points receding at the speed of light from us - the observable universe. Interestingly the light from those points still travels and arrives to us at the speed of light, it's just red-shifted further and further to longer wavelengths, until eventually it stops being a detectable light wave. even if you can see it, you can't get there by conventional travel (sub light-speed) - if parts of the universe recede faster than light you'd need more time than the length of the universe to get there and since they continue to recede from us (currently believed to be at an ever accelerating rate of expansion) that's always going to be the case. So in summary, there are parts of the universe unreachable to us and worse still, un-observable to us! and the universe is stretching, expanding at an ever accelerating rate, so what is contained in the observable universe is likely to thin out on the grand scale (on the smaller scale galaxies and clusters will remain gravitationally bound) - so you could imagine an ever thinning, wispier sponge being ever and increasingly stretched out over time. Nothing with rest-mass can travel with peculiar velocity above c (peculiar, which is the proper name, think of it as relative to the underlying fabric of space). Parts of space can however be expanding away from us (and carrying galaxies contained there) much faster than c (as observed by us) with no contradictions at all. The standard analogy is the balloon model. You're on a balloon's surface and can move around (peculiar motion), but if at the same time that balloon is being inflated then it will appear that where you are things are moving away and points furthest away on the other side of the balloon might appear to move faster than your physics allows... If it is a balloon, lets hope it doesn't pop any time soon...
  14. I think you need a T-adapter for your camera. i.e. a fitting that fits your camera lens mount type on your camera body and provides the standard female T-thread interface. You'll probably find such an item at a decent camera shop or on somewhere like ebay. Normally from that you then use a T-thread to 1.25" adapter that goes into the focuser's 1.25" EP holder, or a coma corrector (2") etc should screw into the T-thread instead and go into the 2" focuser EP holder. if your barlow is T-threaded already (often are) then you just need the camera to T-thread piece) but often you can find the 2 piece kit for similar prices. You'd normally not use the barlow lens itself, so remove it by unscrewing. Unless you're imaging something bright like planets/Moon or really require extra magnification then you can optionally try with the barlow lens in place for a narrower field, at the expense of much longer equivalent exposure times.
  15. I don't know much about the AVX so I won't comment on that. You mention you'll be travelling. I think that rules out the bigger heavier NEQ6. You could as an alternative go for something like HEQ5 Pro synscam ED80 or 130PDS or 150PDS -- This basic setup would then leave you enough to think about guiding, and correctors / reducers and all the various other bits and pieces you might need or want (power tanks etc). If you want to do DSO imaging, the mount and guiding are really key, in a way you're better off concentrating and practicing to perfect guiding and imaging before thinking how to get a really expensive tube. Also the sort of setup I mention above will be relatively wide-field and allow you to get started more easily, if you jump in with over 1m of focal length it's going to be a harder process to get started, you might end up disappointed very quickly. But, if it turns out you really get into planets and very narrow field stuff, you might want an SCT or similar, basically if you want to cover all things well you'll probably end up with more than one tube - so think of it as getting started wisely with £2k in terms of getting stuff to learn and build on and you should be all set of years of fun ahead! Good luck.
  16. You may need to try it out. It might just work, depends on the exact camera etc. Normally a T-ring adapter into the focuser is how you get prime-focus. With a CC it again depends what one and if it changes the focal position. The Baader MPCC is 1.0x and does not move the focus position. Bhatinov mask, yes - you'd normally get one to match the scopes spec (speed, size, focal length) - you should be able to find a universal one matching a 200P as it's a pretty standard OTA. If you really can't get prime focus with your combination then longer screws that hold the primary mirror cell in place will allow you to shift the mirror up the tube to help gain focus. How much would depend, on my 130P I did it and had to move the mirror quite a lot. By the way, the Skywatcher PDS range is designed to deal with this as optimised for prime focus astrophotography - but they are a bit more (but you get a dual-speed crayford focuser).
  17. Thanks everyone. This is essentially what I did get Not exactly great :s but I think that's only a small number of subs as some were blurred (guiding troubles) - so probably about 15mins data or less. Perhaps with an hour + of decent subs something more defined might start to appear. Also has the gradient problem but it's not worth messing with such a low-quality image. Live and learn, will rerty it when the time is right. Maybe the main problem was expectation mis-match, thought this would be bright and easy, in fact it's small and dim, meaning you need much more exposure time than I had attempted to get away with. Also hopefully will have guiding gremlins ironed out over next session or two. This thing about taking various sub-lengths, is there any way to know what might work or is it experience/guesswork/trial and error? thanks again, all good advice and information.
  18. yes it's not black and white, never is - otherwise everyone would use the same place and everything else would fail. Best thing is just to shop around. I like to know I've got a good deal regardless of what I can afford and I'm often happy with second hand with the knowledge I can use it and later sell it on for about the same price I paid, rather than an instant loss. But it all depends, some things I definitely want to own from new. The fact that a site like eBay offers ease of discovering complete cost with P&P and the fact it by definition searches potentially many suppliers certainly makes it convenient place to look and if the new buy-it-now with P&P is as good as from a retail outlet I've no qualms hitting that buyitnow button (it gets pressed a lot!). The other thing is though, I do appreciate local shops. There's a couple of astro centres near (ish) where I am and one near where I work. If I go in for a chat and advice I'm more than happy to pay their RRP even if slightly more than I can find in 'bargain-hunt' mode, to support them - providing it's not a rip off. I really appreciate having shops available for a) the advice and b ) the instant nature of being able to collect there and then and c) being supported if there are problems, so for those reasons I'm always happy to try and support them. Shopping around is healthy, I've made payments to many different astro retailers and suppliers and I think it's good. If you offer something at a good price and have a good reputation then you can expect to take my money when I want that thing you're selling
  19. I've not really found that many astro bargains on ebay tbh. One problem with telescopes is also they end up most often being buyer collects, cash on delivery - and again I'm not often inclined to spend hours driving to save a few $ unless it's a must have bargain. For small accessories and eyepieces it can be great though. I've had a lot of success finding bargain camera lenses etc, new or used near-new that shops always put a premium on. I've not yet purchased any second hand OTA or eyepiece, only new. However, http://www.astrobuysell.com/ is a good place to keep an eye on, I got my HEQ5 pro as new ex-demo there for a very good saving, delivered too in the price - happy days.
  20. excellent image, nice job. That's what I hope (would love to) achieve next time I can. So far results always been a bit grainy due to lack of data i.e. less than 10 subs Do you have good dark skies? your image looks pretty low on noise.
  21. I always compare fleabay prices with other retailers, and look for the best overall deal including P&P. Sometimes ebay is more expensive, sometimes it's the only place to find what you want. For small price items often I can't be bothered to bid, waiting and watching isn't worth the effort. However sometimes it's great, I've got various things including bits of musical gear for far less than you pay in a second hand music shop. Even found good pricing on software. It's one of those usual things, if you're not in a rush and don't mind spending the time you can usually save, but a balance has to be struck. For me it's not worth spending potentially hours to save a few pounds and often when I want something I want it asap, so I look at buyitnow options with low postage. That's the other thing, once you've bid on one item you're sort of in limbo against going elsewhere or bidding on other newer listings. My GSO tube was listed on ebay and that's how I first learnt about it, but I contacted the supplier direct and got it for a good price with other things, so ebay is also a great way to advertise and discover suppliers. Problem is most people know what stuff is worth on ebay, so there are few bargains to be had. Very please with things like BST eyepieces (free P&P) and other such gems on ebay though
  22. hi, thanks for all the great replies. If you'd have asked me about the plate solved image I'd have had no idea what you meant until a few days ago when I signed up astro bin! Here's the image there. http://www.astrobin.com/76634/ which was solved. I'm not sure how to get a copy of a solved plate. I think the framing was a happy accident. I pointed the tube, took a test shot, saw "stuff" was there (much to my surprise) and so took shots for the remaining 10 mins I had left. Hopefully I'll be able to repeat that again, I know roughly how the camera was orientated. It certainly helps once you know what is there already. First shots for me are usually a process of discovery and either, wow that's amazing (like M81, this triplet, M27 etc) or wow that's difficult, like my recent 1st experience at trying M1. As for the stars, yes I think there was a bit of a guiding failure. The settings I used to use with the smaller 130 tube don't seem to quite cut it, also the tube wasn't really balanced much at all so that probably made the mount struggle. And there was a problem with dew on the guider tube! All part of the learning curve. So sounds like lots of 3 or 4 min subs when it's higher in the sky and the weather clears, attempting the same orientation/framing might be something worth attempting at the next opportunity. It's difficult when you don't have clear weather for weeks and the only time you do either there's an early start for work the next day and/or the Moon is full :s all part of the challenge though isn't it, we don't like it to be too easy do we. I'll dig out the tiff and send, be interested in what gradient removal can do!
  23. Thanks for the tips everyone. I'll get myself a black camping mat and some flock material and get to work!
  24. fantastic, love that you can see some of the jets coming out of the core. Much better than anything I've managed so far.
  25. you can run DSS (and registax) on a Mac, either with the usual VM/bootcamp method or in fact you can find it packaged as a Wine mac app where it will run straight on the mac, that's what I use.
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