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lensman57

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Everything posted by lensman57

  1. I doubt very much if this statement is correct. If there is no Bias then the Flats can not be calibrated, nor the lights if there is no Dark frame either. The only way that Bias would not be required is if the Flats are calibrated by Dark Flats and as the Dark Flats already contain Bias then an extra set of Bias is not required, however in this case you would have to take Darks to calibrate the Lights with. Bias is the most important of the calibration frames and the easiest to take . It is a lot easier and quicker to take a large number of Bias frames rather than Darks that in the case of a DSLR are almost always a mismatch or Dark Flats. Dark Flats are only really required if the duration of the Flat frames exposure is long enough to induce noise. This mostly happens if Flats are taken the good old fashion way by covering the scope with a uniform white material and pointing it to the twilight sky as it is supposed to be " flat ". A master Bias made up of about 200 Bias frames is good enough not to induce noise. As for the Flats something like 50 frames is sufficient but Flats have to be absolutely correct to work. A.G
  2. Fortunately it doesn't work like this. I have found that a Baader UHC-s will need +1.5 Ev to a none filtered exposure and +1 Ev for IDAS D1 or P2. The DSLR sensor calculates the exposure on the basis of full spectrum visible light but in AP you want specific bands that the filter will let through. A.G
  3. What is important is to keep the weight of the guide scope as low as possible and as close as possible to the main scope otherwise you will find that the balance in one orientation is not valid in another, same as Newtonian balancing where the tube has to rotated to bring the set up into balance. A.G
  4. Between the two the 428 is a better match to your scopes. The 414 is actually about 10~15% more sensitive than the 428 but I doubt very much if this extra sensitivity is going to be as tangible in practice as it is on paper. I run my 428, 383L+, 314L+ and QHY 8L from a 22 Amp/h Lithium Iron battery. The discharge is flat so the voltage drop is not an issue for normal imaging runs of up to 5 hours. I also have a small deep cycle battery which does not perform as well as the Lithium Iron battery by quite a significant margin and I now only use it for the dew heater strips. Atik cameras are rated for 12V not 13 but I am sure as long as the voltage differential is not beyond +/- 1v this should be fine. I have no experience of Win8 but from what I have read some folks are having problems with this OS and the drivers. I use Win 7-64 pro and it is a stable platform. As someone who does not understand software at all I am bemused as to why Microsoft pushing Win 10 , I believe, when they couldn't get the Win 8 right. A.G
  5. If you want to see what a DSLR can do see this image, it is on the " Deep Sky Imaging " section, http://stargazerslounge.com/topic/246677-dslr-iris-nebula-ngc-7023/. I use both CCD and DSLR for imaging. Sometimes I use OSC and sometimes Mono with NB filters. In the end you use what you already have but the trick is to get the most out of your imaging gear. A.G
  6. This is quite a detailed way of problem solving, however even the original PA errors are pretty small and the guiding software should be more than capable of guiding and keeping the stars round. My guess is that the problem is probably with the scope. A.G
  7. Great image full of subtle detail. I like it very much. Regards, A.G
  8. Great effort. I would not go eliminate all the Green if I were you, after all this is a false colour image. Also try to keep the glow of the yellow/orange hues. A.G
  9. I have recently been having a similar problem to yours. If the target is due south, west or south west I get elongated stars, I do 15 minute subs but the problem is present even on 5 minute test sub. If the target is due east or near the zenith the stars are round. I have offset the mount even more than usual but the problem persists. I have tightened everything up with no effect. Now I am suspecting either the focuser or the mirror housing flexing under its own weight. The PA is usually very good and the PHD graphs are as flat as a pancake. I have not tried an OAG as yet. A.G
  10. This is shear class Manolis. One the best that I have seen of this difficult to image target. A.G
  11. I use PI for stacking and the main processing of the data but sometimes I import the image into PS for manipulation. PS is incredibly good for selective application of sharpening or noise reduction using layers and layer mask. I would say the ratio of processing if an image in PI to PS is about 4 to 1 for me. A.G
  12. Sales people tell you a lot of things such as the max magnification of a 60mm Achromat is 250x . There is a lot more to a camera than just the sensor, having said this I am very happy with my ASI120Mm but I would not go beyond that. American cameras seem to have much quieter electronics than some of the rivals and that is as far as I am going to stick my neck out. A.G
  13. Yes you do need a Barlow of some sort. I use a Televue powermate 2.5X and it is almost transparent optically speaking that is , but it is nearly 5 times the price of some of these so called ED Barlows. I also have a revelation 2.5X Barlow which is fair for the price that I paid for it but not a patch over the Televue. Good luck with your planetary imaging but be mindful that Jupiter is fast setting in the west now and Saturn is in less than ideal position. I have no experience of the Hyperion but I myself would stick with the Televue. A.G
  14. ASI 120Mc is a great camera for a very reasonable price. I had both the 120 Mc and 120 Mm. I sold the 120Mc to one of members here on SGL as I do not do planetary any longer. I use the 120 Mm for guiding. As regards to your set up there is a problem. Unless you have a driven mount keeping the planet on the small sensor is next to impossible. For planetary you would preferably be imaging @ F25~F30 to achieve a decent image scale. Planets are bright but incredibly small and fast moving so keeping the planet centred on a chip of approx. 5x4mm is not easy even with a driven mount. Your budget is very high for a planetary camera, QHY5Lii c for example is less than £200.00 so you may want to see if your budget would stretch to something like a SW HEQ5 Pro or Celestron AVX. These will also set you up for DSO imaging for the future as it will surely come. Besides the Moon there are only Jupiter and Saturn that are available to amateur imagers annually and sooner or later you would want to attempt long exposure DSO imaging with a DSLR. A.G
  15. If cooling is required the QHY IMGOH has active cooling as part of the facility for limited DSO imaging. It uses the superb Sony ICX618 either in mono or Colour. However , there is a question mark with regards to the compatibility of the drivers but otherwise it is a decent package @ £399.00. A.G
  16. If I read the title correctly you want to do planetary, if so then you do not want CCDs optimised for deep space imaging as the requirements are different. For planetary you need a webcam of some sort. Some people modify a normal webcam by removing the IR filter and stick a 1.25" adapter on the nose. This will do for starters and provided that you have a fast scope, about f5~F6 then it can work but sooner or later you want something better. There are a couple of cameras that have proven popular, ASI 120Mc, QHY 5Lii c and the Imaging Source DMK range. There are other options too such the Flea Grasshopper 3 range that use the larger Sony ICX range but these are considerably more expensive than the others by quite a large margin . Hope that this helps. Regards, A.G
  17. Once guiding has commenced the hand controller plays no further part as PHD takes over the guiding, it can be removed from the chain. The problem with this is that if you wanted to move the scope to another target then the handset is gone blind and has no idea which part of the sky is looking at. You would have to reconnect and bring the mount to home position and the alignment restarted so it is best to leave it connected. Regards, A.G
  18. Plate solving is an expression that has survived from the time of the beginning of Astro Photography when large telescopes used what we call plate cameras , 5x4", 10x8" using either glass plates coated with photosensitive emulsion or negatives in another word, and the likes to take photographs of the deep space. The " plates " would then be examined by the astronomers and location of key stars noted for further investigation. Today plate solving is more or less the same procedure carried out by your imaging device. The camera takes a 10 seconds image of a particular portion of the sky and the image is then fed to a Plate Solving software, AstroTortilla, Pinpoint and the likes. These will compare the image to a catalogue of images taken from the sky, identify the area using stars and then slew the mount to the pre determined target Coordinates. Using plate solving makes sure that if needed you can return to a particular target for multiple imaging sessions or just to find a target. I do not use it as it is just another step using software that can cause headache and I really like to find the targets manually but it can be invaluable in some cases and others are very happy with plate solving. A.G
  19. Hi Lee, Here are two of mine. Both taken by my Baader modded 1100d and WO Star71. The one from the IC1396 is pure Ha using an Astronomik 12nm ha filter under the Moon light. Regards, A.G
  20. Use the Histogram transformation and pick out the red channel, move the middle slider to the right ever so slightly and apply the instance and then judge the result. You should really aim to have the left side of the curves intersecting and the peaks lined up. This will not apply if you are in the middle of a large Ha rich nebula, the Ha will inevitably dominate. you should also be very careful how and when to apply SCNR and by how much. The default setting is a little too strong at times. A.G
  21. The prerequisite for imaging at the focal length that you have in mind is a first class mount and this alone will chew up your budget quite easily if not more. This is a rather specialised set up that you are proposing and it does eat up money like no end. An alternative would perhaps be an AZEQ6 and an 8" RC . This is a much more compact and lighter design than your C11 and would require a reducer as the field of an RC is flat. If you could investigate the QSI or SBIG range of cameras with an on camera guider it will reduce the risk of flexure in the train. Unfortunately collimation is something that you have to put up with any mirror based system. A.G
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