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drjolo last won the day on July 23 2018

drjolo had the most liked content!

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About drjolo

  • Rank
    Star Forming

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  • Location
    Nieborowice, Poland
  1. drjolo

    M57 Ring

    Thanks Wim, this year it was 4 hours of Ha and 3 hours of Oiii. So the amount of data for Ha is similar to last year, but I suspect the Moon light swallowed outer shells even in Ha band. These outer halo is really faint, I think at my location it requires about 10 hours of Ha exposure without Moon to achieve good result.
  2. drjolo

    M57 Ring

    I got back to M57 one year later - this time with narrowband data only. Seeing was decent, but transparency was far from perfect and also Moon was present. So outer halo has not been captured. Anyway, here it is M57 in narrowband bicolor only: And both narrowband channels Meade ACF 10", CCDT67, QHY163M, EQ6, Ha 120x2 minutes, Oiii 90x2 minutes (gain 100), seeing good, transparency moderate, Moon present.
  3. There is a free software eXcalibrator http://bf-astro.com/eXcalibrator/excalibrator.htm that can assist you in calibration of the image. It analyses stars color in your image, compares it to star color indexes in databases and then calculates the color correction factors.
  4. All my regulated PSUs show rated voltage when measured with multimeter with or without load. Maybe this PSU is rated for 13.8V, but it is actually not regulated.
  5. You can use nova.astrometry.net to do some blind plate solving and check the target, scale and FOV of your setup. I uploaded your image and here are the results http://nova.astrometry.net/user_images/2836462#annotated Center (RA, Dec): (358.887, 56.557) Center (RA, hms): 23h 55m 32.816s Center (Dec, dms): +56° 33' 24.627" Size: 4.35 x 2.67 deg Radius: 2.551 deg Pixel scale: 9.45 arcsec/pixel Orientation: Up is 343 degrees E of N
  6. And I combined image from the first post with some RGB data. 21-22.04.2019, Meade ACF 10" f/10, AP CCDT67, EQ6, QHY163M, L 400x60 s, RGB 80:50:60 x 30 s, gain=100, suburban sky, seeing and transparency good. PS - I do not remember why I made L frames 60s and RGB frames 30s. I probably had a reason, but it was late, and now I do not why
  7. My whole setup (with guider, cameras, etc) is about 15kg. I can balance it with EQ6 standard length rod, two 5kg counterweights at the rod end, and one small 1kg put somewhere in the middle of the rod.
  8. Thanks a lot! SCT are short but pretty heavy, I think 10" ACF is at the limit for EQ6 class mounts - at least for imaging. Also ACF and EdgeHD constructions are little bit heavier than "regular" SCT. I used to have Celestron 11" on EQ6 and it also performed well, but it weighs more less the same as ACF 10" f/10.
  9. I used to have this corrector some time ago with GSO 150/750 newtonian and Atik 383 as well - I think this is the one https://astrojolo.com/gears/pin-point-stars-on-sale/ - it also reduces the focal length a little. It was never easy to have it all collimated and aligned, but should be doable. These are example images I made with that setup (though resolution is small ) https://astrojolo.com/wp-content/uploads/2016/10/2013-09-06-NGC6914.jpg https://astrojolo.com/wp-content/uploads/2016/10/2013-09-27-NGC6888-Ha.jpg
  10. I already imaged M51 four or five times. When spring comes and CdC shows me M51 high in the sky, I just cannot resist This time I wanted to focus on galaxy detail and features, so I needed to wait for good seeing. In the middle of April a few nights happened with decent seeing and also quite good transparency. Unfortunately Moon was also present in the sky for most of the time, so I did not reach as deep as I wanted, and SNR is also not perfect. But if you take a closer look into the left part of image, below these three bright stars triangle you may spot some faint patches of light - I checked them in SDSS and these are galaxies located 3-5 billion light years away. There are a few more also to the right of M51. And AT2019abn (Intermediate Luminosity Red Transient) has also been recorded Meade ACF 10", CCDT67, QHY163M, EQ6, LRGB 400:40:30:30x60 seconds (gain 100), seeing good, transparency good, Moon present. And luminance only:
  11. Nice capture, and many faint fuzzies in the background. Have you used any coma corrector?
  12. Thanks Yes, I use autofocus and it works well. However I have separate crayford focuser attached, so I do not use OTA focusing knob at all. Also temperature compensation works well in this combination.
  13. Uh, this is amazing image. And clusters are well defined there - I have not seen this image before.
  14. In ZWO drivers it looks much more consistent then. In QHY guys are playing with it from one driver version to another. I used to have unity gain at 130 and I had offset set to 50 then to have average bias frame value at 500ADU, and minimum value at 50ADU (more less). With current version I have unity gain again at 13, and even with offset set to 0 I have mean bias frame ADU over 4000 But changing gain in this driver version does not affect much mean bias frame value, so it would confirm the assumption, that offset here is added after gain stage.
  15. Thats quite interesting problem I think. In CCD cameras there is also offset (bias), sometimes also available to set (like in QHY9), but as far as I know it is very low level parameter. It is the charge added to each pixel before exposure starts to avoid negative values read out from AD conversion. But I do not know how it works in CMOS cameras. It may be as in CCD, or it may be added in the driver level, or after conversion. I am also not sure if offset parameter is expressed in electrons. From my observations it is not the case for my QHY163 camera.
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