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wimvb

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About wimvb

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  • Birthday 29/07/63

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  1. If the cameras can produce raw image files, you can expect better results than with an iphone. Even if you manage to remove the lens, you still need to figure out a way to attach the camera to the scope. Afocal may be the way to go. For planetary, a webcam with lens removed may also give decent results, depending on the webcam and scope. I think I would try afocal or stick to visual, until having saved up for a camera, either a (2nd hand) dslr or a small chip planetary cmos like the asi224.
  2. I know that seeing can be bad, but this bad? I guess you meant "no flats" Nice catch, anyway. Cheers
  3. Is this a single sub, or a stacked image? If the latter, I would examine the single subs. If single subs are ok, it must be the stacking that is causing problems. If this is a single exposure, it seems to me that your optics isn't aligned properly, as @Shibby suggested. Try imaging with another lens.
  4. Looks good. If you use higher iso, you can get away with shorter exposures. I have to use low iso and longer exposures because of high noise in my camera. M51 has low surface brightness and needs more exposures to reveal its structure. To bring out the tidal trail, you need longer exposures, and preferrably dark skies. Have fun
  5. Looks great. But it seems strange that the core is already blown out at 60 secs at iso 400. Succes on a Ha target with an unmodified dslr is very much dependent on camera make and model. The manufacturer's choice of which wavelengths to block and the sensor's spectral response determines the outcome. I have had some succes with 7+ minute exposures on bright Ha targets (california and north america nebs). Good luck
  6. Just posted an image taken with this scope in this thread: You can also have a look here The scope is very similar to the popular 130PDS (which has its own thread on this forum). Just a slightly larger mirror and a longer focal length (750 mm vs 650 mm). Beware that there are several versions of the Skywatcher 150P. The simpler P-version does not have the double speed focuser and is more difficult get to focus with a camera attached. The 150PDS is the imaging version of the scope. Hope this helps
  7. Two nights in a row with clear skies, and here's what I have to show for it. M51 under a silvery moon. SW 150PDS on a SW AZ-EQ6 GT mount Camera: Pentax K20D (unmoddod) at ISO 400 to keep the noise down Guiding: SW ST80 + ASI120MM + Lin_guider on Raspberry Pi 19 x 15 minutes + 1 x 47 minutes (!) = 5.5 hours in total (the 47 minutes exposure wasn't planned; for some reason my camera control program hanged, leaving the shutter open. I forgot to take the image out of the image folder.) bias, darks (600 seconds exposure time), and flats. Most exposures were taken before the moon showed itself over the neighbour's house. Processed in PixInsight
  8. M3

    Once you have the data and calibration frames, all that is left to do is process it all. And that's why the weather gods give us cloudy nights. Cheers,
  9. M3

    Looks good for a single sub. More of the same with this processing recipe, will make it even better.
  10. "At this point we would like to advise our audience not to drink and slew at the same time." And guide responsibly. Cheers,
  11. Splendid. Looking forward to some APODs from your APO. Have fun with it. Even at f/7, your new scope should be easier than your SCT.
  12. Don't you haul out your gear whenever there's risk of a gap in the clouds? I do: () 1. Set up tripod 2. Level 3. Set up mount 4. Attach scope 5. Attach guide scope 6. Balance 7. Star alignment 8. Polar alignment 9. Set up guiding software 10. 11. Detach guide scope 12. Detach scope 13. Take down mount 14. Watch skies clear 15. I'm getting pretty good at setting up my gear to be ready just in time for clouds to move in.
  13. Much better. The Ha areas are showing in red, as they should. On my mobile device, it looks like you got some green left. Hasta la vista green in photoshop (scnr in PixInsight) will remove this and make the red stronger still. As for dark frames, it isn't just a question whether or not, you will have to determine if they work for YOU. That's why I recommended testing. Always take as many calibration frames as possible. I usually take 50 - 60 bias frames (they're easiest), at least 12 flats and more darks than light frames. For darks, I put the camera outside in a dark box with covers, and let it shoot with an intervallometer/timer. You take bias and dark frames to correct for the camera's electronics (fixed pattern read noise and fix pattern dark current/hot pixels). You want as little random noise as possible, since any random noise in the calibration frames will be added to the light frames.
  14. The most important is to find out what works for you. When doing 2-3 minutes exposures, darks didn't help improving the stacked image. I could get equally good results by using cosmetic correction (PixInsight, but also available in dss) and aggressive pixel rejection during stacking. I also used dithering to spread hot pixels. Now that I use guiding, I have longer exposure times (10 minutes or more), and can't do dithering. Darks now help to get better results. What works for me, may not work for you. Therefore: experiment. I also use PixInsight and not dss. The result can very well depend on the software. There are enough cloudy nights to experiment. I would stack the subs with darks, and less aggressive pixel rejection. I would also stack without darks, but with a stronger pixel rejection. Then I would compare the final results. If darks don't produce a better image, you'll have to ask yourself if they are worth the extra time. Nope, the cone is barely visible below the lower bright star. The area is usually much stronger red, but here an unmodded camera is used. Longer sub exposures will help bring out the red.
  15. Nice image, pretty good for an unmodified camera. What exposure time did you use? I think that for Ha with an unmodified camera, you will need multiple minutes sub frame exposures. You should also consider taking flat frames, to get rid of the vignetting. As for darks, you will have to experiment. Some people swear by them, others swear at them. Generally, they can be trickier for dslr imaging, where you have less control over temperature. Using aggressive hot pixel removal routines during stacking, can sometimes give better results than darks. I found that for short exposures, I can get by without darks. But for long exposures (10 min +), I get better results with darks.