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sharkmelley

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About sharkmelley

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  1. Typically sensors are designed with all the AF pixels using pixels of a single colour. Clearly in this case the sensor uses the blue pixels. As for the clip-in filter, it can't be completely ruled out but I honestly can't see how it could aggravate the issue. Mark
  2. You can see the problem in a single CR2 raw file. There's no way DSS settings can affect that. Mark
  3. M51 taken on Wed 10 April including the supernova imposter designated AT2019abn which It was discovered on 22-Jan by ATLAS (Asteroid Terrestrial-impact Last Alert System). Further info on AT 2019abn here: http://www.rochesterastronomy.org/sn2019/sn2019abn.html Some references call it a luminous blue variable (LBV) but it's definitely not blue! Others call it an intermediate luminosity red transient (ILRT). Imaged with modified Sony A7S on Celestron C11 with Starizona 0.72x LF reducer/corrector. 345 x 30sec subs at ISO 10000 giving nearly 3 hours of data. Mark
  4. It's normal. At least it's normal for certain Canon models. It's not a faulty camera. For example, here are some similar threads: https://stargazerslounge.com/topic/315126-lines-across-image/ https://www.cloudynights.com/topic/512886-canon-banding-help/page-3 https://www.cloudynights.com/topic/413422-examining-the-650dt4i-hybrid-cmos-af-pixels/ I haven't yet come across someone saying they solved the issue. It doesn't mean there is no solution - it just means I haven't come across anyone giving the solution. Mark
  5. I was trying to gain an overview of the problem. So you're not using calibration frames (flats/bias/darks)? Maybe you need to do so. Certainly dithering will help hide the issue and that might be sufficient for you. But it's also good to have a better understanding of the problem. For instance, it might be the case that you need to increase the ISO (by the way, you didn't say which ISO you were using) and have the back-of-camera histogram further to the right e.g. 1/3 to 1/2 from the left. It's a strategy I need to use for my Sony A7S. It's also possible that calibration frames (flats and bias) will fix the issue. But without knowing more we shouldn't jump to conclusions. Mark
  6. Those artifacts are certainly caused by the AF pixels. Can you give more information about shooting conditions? What is your sky quality? When length subs were you using and what ISO? Where was the peak of the back-of-camera histogram for both the lights and the flats (assuming you are using flats)? Mark
  7. Maybe it's my sense of humour but the title of the thread amused me: transition from DSLR to CMOS. Since the DSLR is a CMOS, you have successfully transitioned from CMOS to CMOS ? Mark
  8. Unfortunately, the read noise is higher with lower ISO and banding artifacts will also be more intrusive. Mark
  9. The crucial thing is to work out what is the dominant source of noise in your image. Is it read noise, thermal noise or shot noise from the light pollution? If light pollution is your main issue then you don't have a sensor problem. When calibrating using darks, make sure you have PixInsight's dark optimisation switched on - it does an excellent job of scaling the darks to match the lights, despite any temperature differences between the two. Mark
  10. I have no experience with the Esprit range, so I can't tell if that is normal or not. Mark
  11. Let's say 70 pixels. The pixel pitch of the Canon 6D is 6.5microns. You said your scope is f/7. Then given the refractive index of glass as 1.5 and assuming the cause of the halo is a double reflection within the filter glass then that would give a filter thickness of just over 2mm. 2mm thickness sounds about right for a filter. So your halo size is consistent with an internal reflection within the filter. But I can't explain why you don't see a halo with your other scope. Mark
  12. Do you have an estimate for the halo diameter (in pixels) on the Canon 6D? Preferably a halo near the image centre. Mark
  13. You have a new D2 filter? What is the second scope? Where have you mounted the D2 filter on the second scope? By the way, what camera are you using (so we can work out the pixel pitch). Mark
  14. I created a timelapse of the lunar eclipse after spending 4 hours in a subzero observatory taking bracketed exposures every minute. Sony A7S on Celestron C11 with Starizona LF Corrector 0.7x This is created from 220 frames. Mark
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