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michael.h.f.wilkinson

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Everything posted by michael.h.f.wilkinson

  1. The really small galaxies require more than 1 m focal length, and even an EQ6 will start to struggle, I would guess. On my GP-DX I use a 762 mm focal length scope (Meade SN6), but with a smaller sensor and pixel size which gives reasonable results on the likes of M51 and M81. I sometimes struggle to get longer subs working reliably, I should add.
  2. What I mean is I have at times stacked hundreds of 30s exposures (not so much on M42), and got good results. This is 3 hours worth (360 30s subs) of data, still a bit noisy, but I will return later to gather more. For the blown out core of M42, I have combined different subs in Astro Pixel Processor, combined with some unsharp masking to reduce the dynamic range, and that worked pretty well.
  3. Very good first shot, especially from a Bortle 8 location, and certainly for such a relatively short exposure. What camera and scope did you use? Blowing out the core of M42 is a common problem, and combining the result with short exposures helps. I tend to combine loads of relatively short exposures anyway, and get decent results. The "correct" ISO value to use depends heavily on the camera. On my EOS 80D I think 200 is fine, but my EOS 550D works better around 800-1600, I find.
  4. I have Helios LightQuest 16x80s which work well enough on a monopod with ball head and trigger grip, but 25x100 bins are considerably beefier, so I am not sure that they will hold that weight. My Falcon-Eyes pistol grip is listed as suitable for 4 kg load, whereas 25x100 bins can weight in at 4.7 kg.
  5. I image from a suburban garden, which has quite some LP, but I still manage to image galaxies, with a CLS clip filter in my (modded) EOS 550D. Got some quite decent results on M31 and M33 with my 80mm F/6 triplet and 0.8x reducer This is a crop, and only represents about one hour of data. I also use a Meade SN6 6" F/5 Schmidt Newton, with ASI183MC and simple UV-IR block filter and get good results with many galaxies, especially by imaging near zenith whenever possible. The image below is 5h of data on the Leo Triplet
  6. Welcome from the north of the Netherlands, Peter. I still have my good old C8, great scopes. Clear skies!
  7. Haven't done much H-alpha imaging, as the sun is indeed to low to pick up from my back garden. Besides, the weather has been horrible. I do occasionally observe in H-alpha from work, where I sore my Coronado scope. Regarding lunar mosaics: I like to stroll around the hi-res version, or zooming out to see the whole moon. I might have one of these printed on a HUGE poster and hang on the wall
  8. Managed to capture enough data for a 10-pane 104 Mpixel mosaic using my Celestron C8 and ASI183MC camera. Seeing was a bit up and down, but I syill got a decent result. Each pane was a stack of 200 out 1000 frames, stacked with AS!3, stitched with MS-ICE, luminance channel sharpened in ImPPG, and recombined with colour in GIMP Clicking on image to view full resolution highly recommended
  9. Bright moon out with lots of hazy clouds, and a big halo Couldn't resist setting up the Celestron C8 and do my first lunar imaging of the year Seeing is a bit up and down, but we will see what comes out
  10. In the past I have used some hairs from my head (dwindling natural resource in my case too), as these were much thinner than any wires I could find. It wasn't easy to stick them on, however.
  11. In a Plössl eyepiece (and many others) you can attach the reticle to the field stop (as was easy in the Antares Erfle), then it should be in focus
  12. I turned an Antares 25 mm 70 deg EP into an illuminated reticle EP. I got a reticle from the Surplus Shed, but I am not sure they have a suitable one available.
  13. Much to my surprise I was able to see the sun today, around lunchtime. I rushed out the Coronado SolarMax-II 60, and was pleased to see quite some activity on the southern hemisphere. Earlier in the morning I had already spotted a sunspot with my Lunt 8x32 SUNoculars, and the spot was also clearly visible in H-alpha, just east of the meridian, south of the centre, some complicated plage and filaments could be seen around it. Further eastwards, possibly belonging to the same AR complex, a bright patch of plage stood out, with some thin dark filaments surrounding it. On the western half of the s
  14. That is completely different. Adding vanes to the scope is mathematically the same as convolving the image with the corresponding PSF
  15. Same for cat people with their SCTs, Mak-Newts or Schmidt-Newts
  16. Why not just convolve the image with the required diffraction pattern?
  17. M42 indeed. At longer exposure, and somewhat longer focal length, it looks like this, where you can see just two star s of Orion's belt at the top, and M42 is shown somewhat overexposed at the lower right
  18. Didn't the Michelson-Morley experiment show the speed of light in both directions was the same? This suggests (but doesn't prove) isotropy of c.
  19. Here in the Netherlands the weather isn't exactly helpful either. I haven't been doing DSO imaging that long or that intensively, so there are still lots of fairly bright and big targets to chase. What I intend to do is keep going at some targets over and over again to see how much I can tease out of the object, simply by combining shots from many sessions. Case in point has been last summer's attempt at M27 with the Meade 6" F/5 Schmidt Newtonian. After gathering over 13 hours of data, I start to see the fainter outer shells This is a lot better than the first image, which only had
  20. It is now listed as mag 12.6. Still no clear skies in sight
  21. Not entirely sure, but it looks like a gradient due to LP, so try "light pollution removal" under "tools" in APP, to see if you can get rid of them. You simply select at least 5 boxes that don't contain diffuse nebulae (stars are OK, they get ignored), and press calculate. This can help a lot.
  22. I personally almost always use my flattener/reducer (0.8x) with my APM 80 mm F/6. Imaging at F/4.8 really helps, and the field is nice and flat. On the rare occasions I don't use the reducer, I do insert the 1x flattener I got with the scope.
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