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Everything posted by D4N

  1. Undo the three small silver screws at the bottom and remove the cover plate, the collimation screws (big silver Philips) and locking screws (small black grub screws) are inside. Don't touch the black screws around the outside of the tube, they attach the mirror cell to the tube. The manual is dreadful for this scope, Skywatcher should really sort it out as it is quite a popular scope.
  2. So the XT12i is a push-to dob, it has encoders and can tell you where to point it but won't track on its own. It is priced very similarly to the SW250P goto dob which at under £1000 is still within your budget but obviously smaller aperture. I don't think there is anything bigger than 12" that will fit your budget, the 350P is just outside of it. Personally I got a goto dob for the tracking, the goto bit is nice but it was the tracking that made me want it. I tried it manually when I first got it and found the moon went past pretty fast at high magnification, at lower magnifications it is fine though and wide angle eyepieces are really nice in it.
  3. Judging by the pattern I would say that it is reflections off the micro lenses on the sensor itself.
  4. I think the proposal in the first post wouldn't come under that as it is technically just an extension lead buried in the ground not an actual socket.
  5. This should have no permanent effect on the RAW files as all the original data is kept so it doesn't really matter. Important stuff is gain, exposure time and resolution as these can't be changed afterwards.
  6. I think outdoor sockets don't need to be on the RCD so you may not be protected by that. Easy test is to trip the RCD and see if there is still power on it. I have run armoured cables under my lawn but both ends terminate at a junction box rather than sockets. In areas where it s near the surface protection is increased with some metal pipe.
  7. The depth to which a mirror is ground will determine its focal length and since focal length is directly connected to magnification it will effect the magnification.
  8. Pixinsight. https://pixinsight.com For Nebulosity it should output colour if the demosaic settings are correct so you should check these.
  9. The problem you get is that it is very hard to build optics that gather more light without also increasing the focal length, this has the side effect of increasing magnification. My 2.1x42 binoculars are really nice to use, they have very little magnification but greatly increase brightness.
  10. Ah have you paid for the full version? The demo version saves stripes on files. Unfortunately this means that stacked images can look a real mess as the stripes go all over the place. PI runs natively in OS-X, I use that for processing. I use Nebulosity or Artemis for image acquisition.
  11. I have a polarising filter for the moon, it certainly can get a bit bright. Be aware that resolution is a function of aperture so whilst using the removable cap in the end cover will work for reducing the light coming in it will also reduce the maximum resolvable detail.
  12. If your images are coming out monochrome then perhaps the software is not debayering them before stacking. Colour images need to be debayered before stacking or it will just make a mess.
  13. Start again, you can separate them into separate groups if you have new calibration files though. You can also get DSS to save the calibrated light frames to save recalibrating each time you add more data.
  14. You can do that if you have a way to connect the camera to the eyepiece. The webcam adaptors normally provide a 1.25" nosecone that will fit into the focuser but this is no good for most eyepieces. Some eyepieces are designed to be used this way though, I have some Baader Hyperion and Morpheus eyepieces that have a thread under the eyecup, there is then an adaptor to T2 thread which is the most common thread for Astro imaging cameras. However those eyepieces are not cheap. So optically speaking it is possible for a camera sensor with no lens to reach focus whilst behind an eyepiece but it can be difficult to make it fit if the eyepiece is not designed for it. The other thing you can do is use spacers to increase the distance between the barlow and the camera, most barlows produce a divergent light cone so the further away the imaging sensor is the larger the target will appear on the sensor.
  15. Ah ok this camera is designed to be used at prime focus, you would not normally have an eyepiece in the scope as well. Whether it would work with a barlow will depend on both the barlow and the cameras adaptor.
  16. I think the first rule to buying a zoom lens is to avoid 7-21, they have a really bad reputation. What camera are you imaging with? I think the image will be quite dim with a 7mm zoom and a barlow.
  17. I assume you mean so you can take pictures with it? Something like this could work: http://www.rothervalleyoptics.co.uk/bresser-universal-smartphone-adapter.html I don't have one myself so don't know how good they are.
  18. Yeh the right side looks like minor coma but the left side is a bit of a disaster. It looks like the left 1/4 of the image is noticeably darker and the stars are smeared oddly. Does it stay on the left side of the image if you rotate the camera / corrector in the focuser? Maybe something isn't square, how is the camera / corrector connected to the scope? I would use this as the perfect excuse to get a small format CCD that will conveniently only see the good bit in the middle
  19. Ursa Major and Leo are great constellations for galaxies. I love it when I can get more than one DSO in the fov at a time, that gives you more appreciation of the difference in the shapes of the fuzzies. Averted vision helps as does roving your eye around the fov but avoiding your blind spot as you won't spot anything with that Your blind spot is off centre, to the left of the centre of your fov for your left eye and to the right of centre for your right eye.
  20. What budget are you looking at?
  21. Baader modified means that the IR cut filter has been replaced by a Baader one that will still cut IR but will allow through the Ha wavelength. http://www.baader-planetarium.com/en/filters/dslr-astro-conversion.html Doing this makes the camera usable for normal photography and also removes the need for an IR cut filter (although the latter makes no difference if you use a UHC-S filter while imaging anyway).
  22. It depends somewhat on the bandpass of the UHC filter, mine has UV/IR cut built in so the fringe killer would have no effect as that part of the spectrum is already being blocked.
  23. The optimum gain setting varies between cameras so no one can definitively advise you on that unless you say which camera you have. 800 is about average though. When you will overexpose depends partly on the target and partly on the light pollution. Some targets have bright elements that will blow out and will need shorter exposure or a mixture of short and long exposure to deal with this. I found I could expose for half an hour with my DSLR if I used a UHC-S filter.
  24. The mod makes the camera more sensitive to Ha common in emission nebulae, in most cases it is of little benefit for clusters or galaxies. If you are imaging emission nebulae it can drastically reduce the exposure time needed. I don't know anywhere in your area that will do the mod but it is fairly easy to do and I imagine there are camera repair shops where you are that could do it. A lot of what makes CCD imaging good is low noise, unless you cool your camera you won't be able to match that.
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