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Catanonia

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About Catanonia

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    Always Learning

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    catanonia@blueyonder.co.uk

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    Male
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    Sunny Sandbach UK
  1. Best DP I have ever seen :)

  2. It is not a well known or accepted CCD and does have it's peculiarities at time. I like the cooling, it set it to -20 and it has no issues getting there. The large sensor format based on the Kodak 8300 chip is nice. But there are issues with condensation causing chip issues where the liquid vapour would short out the CCD pins. This has been resolved in newer QHY9 CCD's, but I have had to return mine once due to this and it goes all the way back to Asia for this. The filter wheel can be a pain with its design and getting on other parts into the optical train, so hunting for correct adapters can be fun. Image quality is very good, low noise, but mine has started to develop quite a few hot pixels after 3+ years. The support on the website / forum is good and very helpful. Overall, yes I am pleased with it and worth the money (cheaper than other types) at the time. Especially if you get the mono + FW + 2 inch filter combination deal.
  3. Really close to the moon last night and was having all sorts of flat / dark calibration issues along with fogging of my CCD. I managed to stack together 13 x 10minutes 7nm HA with my 8inch Newtonian running at F2.8 (ASA corrector) and the QHY9 Mono. Learnt a lot about the peculiarities of Pedestal values, noise in darks etc etc, but I managed to pull a semi decent image together. It also looks like I have a bent spider vein looking at the spikes on the bright star. Still also getting comet tails on stars on the top left quadrant (bottom left before rotation) and it is really really bugging me. Must be tilt on that part of the CCD that really shows @F2.8 Any way, hope you like a quick Jellyfish.
  4. Grrr, Learnt why my flats sometimes didn't work properly when being subtracted in calibration. Basically "sometimes" 50% ish of the time, my flat files have a Pedestal FITS header of 0 in them and my images don't have anything and when this happens the calibration fails. I do the following all of the time using lights only (option in Maxim when imaging) Image at 60 - 600 seconds lights Take flats of 1 - 2 seconds to get 1/3 well fill and I take them as lights Calibrate Now step 2 in MaximDL sometimes adds the pedestal of 0 into the FITS files for the light flats and sometimes does not. None of my light images ever have this Pedestal and hence the problem. I have a work around of using MaximDL to remove Pedestal and re-save the image, but I would really like to know why MaximDL is adding this pedestal to the light flats sometime and sometimes not. I don't get it. NOTE : I don't use any calibrations in Maxim, I only use it to take images and save them. It is a standard install of Maxim with nothing changed in the options. All calibrations etc is done in PixInsight. Thanks for anyone that can explain what is going on here
  5. Some confusion with my post. I was referring to cooled CCD's and hence a library of darks at a set temperature. Apologies for any confusion and of course they do reduce thermal variations in CCD readout. I thought somehow you meant thermal currents in the tube. Also when I take my darks library, I take the CCD camera off the scope and put a proper lens cap on it to ensure no stray light as Olly says will always get into a newt. Darks, flats, bias = massive debate with everyone doing their own thing
  6. Nice image and PixInsight is an art form in itself. With regards to DBE : Did you do the manual method with your own points or the auto method. The reason for asking is top left quadrant seems to be overly red and a sign of not quite DBE methodology applied.
  7. Catanonia

    M51

    Well captured and extremely good processing
  8. Not heard that before. Darks are taken to remove the noise the chip makes due to electronics. Having a cooled CCD reduces the noise, but darks are best used to remove the random noise effect.
  9. Darks :Build a library of darks for all the exposure times you use, create a master for each and re-use them for about 6 months Bias : If you are using darks, no need for bias as it is already in the dark Flats : Shoot these every image session to ensure all dust bunnies etc are accounted for. If your image train isn't moved or rotated, then you can re-use the flats.
  10. I think you may be right. Your set up as far as focusing is concerned, is not the same for each filter. You have 2 options 1. Manually change the focus per filter shot or concentrate on one filter run at a time 2. Buy a computer controlled focuser, set and calibrate it to do the manual shifts when the filter changes. This will not stop temperature differences, unless the software you use in option 2 has a measuring method to automatically pick the correct focus. But that said, I have never run into temperature issues even at F2.8 once everything is cooled down. The BMask will work for the current filter in place which in your set up is not the same for all filters hence the issue. When I bought my QHY 2inch filters, I made sure that they were par focal (same focus point) to make sure this didn't happen to me. But I have the same issue with my Ha filter which is not par focal to my LRGB ones and hence I concentrate on either Ha or LRGB for a session or re-focus when I switch 1/2 way through the night. At F6 your are on the edge where small amounts are noticeable in images. Also, you may not have focuser flex, but your CCD may not be totally square with the imaging plane = tilt and hence the star shapes differ in the image. Focusing will "hide" this some what, but I would check your CCD is square. I use digital callipers to check and adjust the camera housing screws to try and dial it out.
  11. What scope / focuser / camera are you using ? If your stars are behaving badly in the same quadrant it could be down to the dreaded camera tilt, depending on the F ratio you are running at. I had massive issues on my set up with a fast F2.8 Newtonian and heavy camera set-up. It was causing the focuser to bend and tilt the image giving massive issues. The faster your scope in F stop, the worse it gets. Bad collimation will also make it more evident.
  12. That is cracking and a superb result. I remember trying to do this from my not so bad light polluted garden for 16 hours and didn't get 1/2 this amount of flux. Top drawer and great processing to drag out the flux.
  13. That is nice and sharp, good job.
  14. Sweet, it is amazing how much of the faint outer regions Ha brings. The danger is to make it look too much like an oil painting with over enthusiastic processing, something I am very guilty of myself. But I think you are very close here, good job. How did you merge the Ha element into the image ?
  15. The bottom one is out of focus. Always best to buy par focal filters of the same brand that meet focus at the same point. Otherwise you will need to manually change focus during each filter change that can be a pain. Less defined will not give out of focus stars, look at the 2nd image bottom left quadrant and you can see the out of focus stars. Not by much but enough to see it. Your guiding or collimation is slightly off too by the looks of it. Not much experience of motorised filters, but with the right software, you can change the focus per filter, but again it can be a pain. Best to have par focal filters.
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