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Photosbykev

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Photosbykev last won the day on August 13 2015

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  1. 30+ exposures between 1 and 60 seconds with an ASI533MC_Pro and WO61 refractor. The huge dynamic range makes this a real challenge lol
  2. Comet C/2019 Y4 (ATLAS), currently 160 million kilometers away from the earth and motoring along quite nicely. This short timelapse consists of 100 x 60 second images taken over 150 minutes with a ASI533MC-Pro camera and William Optics Zenithstar 61 refractor captured with APT and post processed using PixInsight Blink for the animation. The bright star lower right is Althiba IV Comet C2019 Y4 ATLAS.mp4
  3. I'm looking to install a 5 x 2" filter wheel into my system to replace a 2" filter drawer which isn't lightproof. I'm favouring the Starlight express 5 x 2" filter wheel with T2 threads and the hall effect sensors for precision filter positioning. Any negatives about using this wheel? regards Kev
  4. Thank you both for confirming my thoughts on this. I suspect I won't run into any issues with stars in the corners using the small sensor on the ASI533 even if I removed the flattener. As it doesn't change the focal length of the refractor I may as well use the screw adjustment built-in to fine tune the back focus adjustment. 17.5mm - ASI533MC-Pro camera front face to sensor 17.5mm - Starizona filter drawer so I need around 32.7mm extension + 0.6 or 0.8mm for the filter thickness so approx 32.5mm extension tubes Kev
  5. I've just acquired a ZWO533MC-Pro to mount on the back of a William Optics Zenithstar 61 refractor with the dedicated PFLAT61A flattener. I have been using the refractor and flattener with a Canon DSLR and have set the adjustable flattener to 12.9mm when using the T2 mount and the stars are nice an sharp corner to corner. Anyone using the WO61 with dedicated Flat61A adjustable flattener with a cmos camera? The back focus according to WO is 67.7mm from the rear shoulder of the flattener to the sensor BUT is this with the flattener adjustment set to zero mm adjustment rather than 12.9mm? and can I use that screw adjustment to set the back focus to exactly 67.7mm after fitting extension tubes and filter drawer in the optical path? regards Kev
  6. Just need to wait a few months for clear skies lol
  7. Light leakage doesn't make sense as all the other darks are fine. The canon sensor does have bias noise along the bottom edge but no obvious amp glow. It does look like light leakage but how I'm not sure. I'll reshoot them and check the individual files Kev
  8. Problem solved but I don't know the cause. Two of the thirty dark images look like this heavily stretched!! New darks required lol Thanks for all the input folks Kev
  9. I shoot the flats immediately after the imaging session with a battery powered flat field panel so it's very dark lol. I think the flats are ok looking at them in PI, certainly not significantly different to other flats I've taken. It's only when I add the darks to the calibration stack that the image gets the curved banding across it in the lower right corner. It isn't the standard Canon sensor banding issue which I normally correct in PI anyway regards Kev
  10. Thank you for the input CJ My darks are normally very good as I do cover the refractor with it's dust cover and then slide a black fabric bag over the end to make sure the objective end of the refractor is completely blacked out and the camera viewfinder eyepiece is covered with a custom eyepiece blank. The darks and lights sensor temperature were within 2degreesC of each other so I'm struggling with why they should be wrong. I can reshoot them, and probably will, one evening this week when the temperatures get down to around zero ambient and check the second dark set. regards Kev
  11. Delivery delayed two weeks lol At least it will be ready for the next new moon lol
  12. The screen print below is of two images containing identical lights, flats and bias frames. The right hand one has a fresh set of Darks added. The 240 second darks were shot at the same iso, exposure and temperature on a stock Canon 5D4 I've process the two images with exactly the same PixInsight settings (just background neutralisation, colour calibration and stf applied to see them) DBE wasn't applied because that would affect the output for this test. I'm getting these strange slightly curved bands, ringed in the right hand image when I add the darks during the calibration routine Is it possible to shoot bad dark frames? Previous sets of darks on the same setup have worked correctly so I'm struggling to see why this dark set would be 'faulty'? The same effect is seen on other data sets as well using this set of darks. For reference this is what I get with a basic edit from the lights/flats/bias image regards Kev
  13. Welcome on board, just up the road in Churchdown
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