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Merlin66

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Everything posted by Merlin66

  1. Noeltg, I’m close to Melbourne, the scope should point towards the South Pole with the weight pointing down. Clamp in this position, and use the hand controller to move the scope.
  2. I understand your concern, but the NR can only arise between very closely spaced surfaces. The cover plate on the chip I’m sure is 100% designed for the normal camera application, not for narrowband Ha solar imaging. The spacing of the coverplate to the silicon is restricted, likewise the thickness of the coverplate. The front window is to far from the chip to generate NR. Note, NR May be generated in Ha wavelengths, but not an issue when Imaging in CaK.
  3. Ok. But the front window has nothing to do with the NR
  4. Rusted, et al, The Newton Rings are caused by the sensor chip cover plate, the exterior coating (AR), thickness and material all have a part to play. This “cover” is an integral part of the chip and is not removable. I think you be thinking of the protective “window” added to most (all?) the current cameras - these can be removed for cleaning. Some chips are more prone to NR than others. The only “solution “ is to change the effective thickness of the cover by tilting.
  5. I've prepared an English translation of the SolarRuler, which may assist. SolarRuler-v4b_e.pdf
  6. It seemed to be over x16 the diameter of the Earth in height. Flares like this only survive a few hours.
  7. Applying the grid to the Gong image: It shows the prom height is greater than 200,000 Km! That's roughly 16 times the diameter of the Earth.
  8. With the attached overlay you can estimate positions and sizes of the proms. RegleSolaire-v4b.pdf
  9. Still fighting heavy cloud bands moving across, but some results. CaK and Ha
  10. Obviously a 100mm aperture, under good seeing, and good eyesight, are capable of resolving this double double.
  11. A thin black thread separation is the “minimum “ Takes time, this is not a 30 second challenge. Good practice to train your eye. It’s a bit like running....everyone can run, but few have the dedication to run properly. Takes practice and rigor and some dedication. The more you look......the more you see.
  12. Train your eye. Concentrate on the image, hold your breathe and pump the oxygen to the brain. When you can split the double double, OK, move to a lower magnification. Take your time - train your eye.
  13. Steady seeing, good optics and practice..... that's the challenge.
  14. Ok. I cleanly split the double double while in Belgium. Using a 4" Genesis with a 10.4mm Plossl (x49) (I believe some others have actually managed with a slightly lower magnification - there was a thread a couple of years ago)
  15. Luke, Interesting.... I only use the ASI 174MM and the ASI 1600MM for solar imaging. I work at unity gain for each camera and vary the exposures (surface/ proms) I tried to find the gain settings for the QHY5L II but didn't find any definitive data. Could it be related to your gain settings?
  16. Nicos, The spherical and chromatic aberrations are not always well corrected at CaK wavelengths.
  17. Yeah, the UV wavelengths can give better resolution, but the seeing gets worse. Also the capabilities of some (most) refractors to imaging at CaK are less than ideal.
  18. Yes, I believe the Lunt has the same requirements, the CaK bandwidth needs at least f10.
  19. Pretty good result, well done! In Oz things can get pretty hot during the day.... after ten years of working with a 80L grey tube on the picnic table to shade the laptop I've gone for semi-remote control. Extended all the cables (handcontroller, power, focuser, and camera) to allow me to work in the comfort of the local office. Seems to work for me.
  20. Nicos, I use a DIY CaK filter. It really needs at least an f10 beam to perform well. (f15 would be even better!) I stop my ED80 down to 60mm to achieve the minimum f10. Firecapture for image acquisition, I'm using a ASI 1600MM, stacking in AS3! and final tweaks in ImPPG. I find an electronic focuser (I have a SW motor belt geared to the 10:1 focus knob) mandatory. Takes practice, but when the detail just crisps up you know you're close.
  21. Early observations showed a CN emission, but this has not been recorded in the spectrum for some time, similarly, the initial bright Na (Sodium) emissions have gone. See Torsten' spectra
  22. The green "glow" is coming from the Swan bands. https://en.wikipedia.org/wiki/Swan_band
  23. And the answer is.......????? (I also found the FFT didn’t work too well. The best results so far have been with the T2 tilter) what camera are you using?
  24. The "ST-4" is just a connection method for providing guide movements in RA and Dec, based on the original SBIG ST-4 (now long gone). The ST-4 became the de facto standard for guide camera connections. Yes, PHD2 gives you the option of using the ST-4 connection based on the setting - "On camera"
  25. This effect was well shown in a recent post on IIS. The animation shows the dramatic increase in ring brightness at opposition. http://www.iceinspace.com.au/forum/showthread.php?t=184704
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