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About Delboy_Hog

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  1. Thank you Vlaiv, that's a helpful explanation of what's going on here. I'm currently looking into the various bits of software that I use as compared to some others, so I'll take a look at APP - it would be helpful if there was something out there that could help with this, though I'll certainly be looking to significantly reduce the size of the dither on my next session, so hopefully that'll give DSS a helping hand in the meantime! Thanks again, Derek
  2. Hi David, So sorry for the slow reply, especially after the efforts you went to with the data - I've had to be away with work and it's given me no spare time at all. Many thanks for taking the time to run through with the data and seeing what you could get out of it...HOLY MOLY! That's looking nice! Especially with limited data, as you say. You seem to have managed to minimise the tragic corners better than I did, and it has a really nice balance to it, to my eye. My processing always seems to come out a bit stark and...obvious, if that makes any sense? I've still not had time to run this through in Photoshop, so I must try it. Hoping for some clear nights to get some more data in the stack too. As for whether I included flats in the light frame stack...ha ha, possibly! I've made more stupid mistakes than that in the past!! Thanks again for your help with this, and for walking me through what you did in the stacking phase, that's very much appreciated. I really like seeing the starless version too, really interesting to see - I'm assuming that's a Pixinsight feature - lovely! Hopefully I'll be back on here before too much longer with a bit more data and having had slightly more success through the stacking! Thanks again Derek
  3. Thanks David, much appreciated. Yes, straight off the camera - I was really pleased with the individual subs, so was a bit bewildered with what came out of DSS! Oh I'd be intrigued to see what anyone else could get from the data - I've uploaded the light frames to Dropbox here (hope this link works?): https://www.dropbox.com/l/scl/AACWyRfxTlCwi4kLul4poTuMl6zmhaN8Vew It took an age so I haven't uploaded the flats and bias frames as well, but if anyone is particularly keen to play with the data, I'd be happy to! Many thanks, Derek
  4. Hi Michael, Many thanks for coming back on this. The Star Threshold is an interesting question actually - I think I went with the standard DSS setting, and remember it found several thousand stars, which seemed a bit many - I've read somewhere since that about 100 stars is optimal, does that sound about right? Do you have a particular threshold that works for you, or would it vary depending on your target? Thanks again! Derek
  5. Thanks for this Pete, that's really helpful. I'll definitely be going for much smaller dithers next time around. Your suspicion about my polar alignment could be spot on too. I guess field rotation over that kind of time-frame would explain why the individual subs had no trailing, but the final product wasn't spot on... I'm interested in this - if there had been field rotation, that would be reflected in the "angle" column of DSS, is that right? I noticed there were some differences in the figures in that column when the frames were stacked. Probably only about half a degree over the time period these frames were taken in - would that be enough to give the stacking a hard time, do you think? The Synguider appears to be pretty good at continuing where it left off, once you 'resume' from its previous calibration run, so I've only been allowing a few seconds. But then I hit restart on the intervalometer, which gives it a few more seconds to settle I suppose. It always feels quite time-consuming at the time, but I've no doubt it's worth it for the noise reduction it brings. Thanks again! Derek
  6. I don't know what's causing the problem...although I think it might be the images rather than the stacking. Either way, I'd be **really** grateful for your help! Short version of the question: How can a series of seemingly ok individual photos without any obvious signs of trailing, come out of DSS in such a calamitous mess!? Longer version: I've been trying to capture as much of the Veil nebula as possible in a single frame, with the Canon 6d, Skywatcher ED80, HEQ5. 5 min subs at ISO 1600, guided by a Skywatcher Synguider. Utterly fabulous patch of the sky, I always think! All of the individual light frames look reasonable (albeit to my admittedly un-trained eye) - example frame below. But stacking them results in something that looks like one of those hidden / 3d image things that make you feel a bit sick if you look at them for too long!! On the plus side, the calibration frames seem to be evening out the illumination across the field of view, and got rid of the dust-bunnies! My guesstimate of what's going wrong: 1) I gather the 6d is not a great match for the ED80 because the chip isn't fully (evenly?) illuminated. I may have to accept that the corners will always be ropey, and be prepared to crop significantly? Can flats do anything about the star shapes, or are they all about the illumination across the field of view? 2) To compound that, in my over-zealous attempt at dithering, I attempted to manually dither the frames (stop the autoguider, tap the arrow on the handset to move the field of view slightly, restart the guider, start the next frame), but I wonder if some of the movements I made were too big. I read that only the tiniest of movements is required, so have the bigger movements made it harder for DSS to stack those streaky corner stars? (e.g. if it's trying to stack a seriously sausagey corner star from 1 frame with a non-corner, non-streaky corner star from a different frame, it's going to struggle? Example of the light frames: And the images: straight out of DSS, no processing... Lights and calibration frames - check out those corners!! Light frames only, and took the lowest scoring frames out of the stack...about the best of a bad bunch - though the corners (especially the bottom left) are still a mess...still, I could probably process a crop of this? Last one - a hideous attempt at using Kappa Sigma process on the light frames - it appears to have focused on aligning the stars in the corner, rather than in the middle....appears to have worked on the satellite trails though!! Some bonus questions for any DSS experts out there: 1) I gather the "Kappa-Sigma" setting in DSS is the best approach to remove satellite trails - is that Kappa Sigma or Median Kappa Sigma? 2) And is that just on the light frames, or do you apply that approach to the calibration frames as well? 3) And do people just use the default settings when you choose one of these, or do you change the Kappa figure or the number of iterations? Many thanks for any light you can shed on all of this for me! Derek
  7. Been practising the set up and polar alignment of my Star Adventurer through the short nights in the hopes I can get started on some proper imaging now that the nights are getting a little longer. This was a (cropped, but otherwise unprocessed) 7 min exposure of the tail of the Plough (Alkaid, Mizar / Alcor and Alioth), taken just a few days after the longest day - admittedly I'm only using an 85mm lens at the moment but I'm still delighted with the tracking capabilities of this little mount! Check out M51, M101 and M63 all in frame! Think I must have just cut of M106, which is a bit of a shame... Getting some curious star shapes in the corners with this lens (could I ease that by stopping it down a bit, do you think?) but otherwise it's looking good for some seriously deep Cygnus time over the next couple of weeks! 7 minute exposures with anything approaching f1.4 is hugely exciting! Star Adventurer Canon 6d Samyang 85mm f1.4 stopped down to about f2 ISO 100 (to prevent total over-exposure!) 1 x 7 minute exposure
  8. Hi all, A little while back, I took a sequence of photos of the sun, with the intention of doing a time-lapse. Unfortunately, before my planned sequence of photos had finished, I had to move my mount and scope because the sun was about to go behind a tree (poor planning on my part, I know!). The problem is that in moving it, I loosened the clutches on the HEQ5 mount, so the camera was (unbeknown to me at the time) rotated a few degrees out from where it had been previously. When I've come to making the time-lapse, there's a 'jump-point' where the features on the sun's surface in the animation jump to a slightly different place. To add to my problems, the features in Windows Photos and the various online tools that can rotate an image by just a few degrees, resize the image in doing so....so I can correct the angles so that the features appear in the same place throughout, but now the jump-point in the time-lapse is a significant re-sizing of the sun, which looks equally weird... Has anyone made this mistake before, and does anyone know if / how it's possible to rotate a photo by just a few (probably 15 or so) degrees without re-sizing the object in the photo in doing so? Many thanks for any light you can shed on this for me! Derek
  9. That really is epic Olly! Congratulations on another cracking image!
  10. Hmmm, a difficult choice, and one I can certainly relate to. Can't help on the pros / cons of various pixel sizes I'm afraid, but for panoramas and nightscapes, I opted for the 6D, and it's an absolute beast, especially if coupled with a fast, wide lens (I highly recommend the Samyang 14mm f/2.8 - excellent value for money in my view, in a market where you can spend *way* more, depending on the brand). The difference in image quality from my old 1100d is very significant, and worth the higher cost for me. Maybe spend a bit of time looking at other images on here or on 'Astrobin' - it might give you a better idea of what you can expect from the various combinations? My only caution with the 6D route would be to check the budget for the inevitable extras - spare batteries, carry-bags etc. Unfortunately I made the mistake of strapping my 6d to my ED80 scope and now I don't want to go back to using the 1100d and want a second 6d - one for widefield, one for the scope... Unfortunately the piggy bank is empty, so that's a no-go!! I have no experience of the 800d I'm afraid, and others with experience may shout me down here, but I worry that the 800d won't feel like a significant enough upgrade from the 1000d. I have no doubts that the 6D images will feel like an upgrade. The obvious problem with that could be (and was for me) that it prohibits other purchases until funds recover. So you might have to prioritise what you fancy doing most, between a widefield nightscape set-up and a deep-sky scope / mount set up. Good luck whatever you decide. Enjoy the feeling of excitement that comes with deciding new astro-purchases!
  11. Lovely image. Wowsers, 20s subs? That camera is a beast. I've been eyeing up the Leo Triplet with a view to hunting the tidal tail, but reckon I'd need 20m subs at least, and that's with the 6D, which is pretty sensitive. I wonder how long (or rather, how short) an exposure you'd need to find it with the A7s? Keep up the good work - looking forward to seeing more of your images!
  12. Ah fab, thanks for that Charl - I'll give it another whirl and see how I get on. Thanks, and congrats again on the images!
  13. Nice catch Charl, and a couple of really crisp images as a reward! Do you mind my asking how you're stacking your lunar frames? I've been meaning to go back to taking more photos of the moon, and had previously used Registax. Think I've had some windows update thing since last time I did that and for some reason it now seems to struggle and crash when I upload either raw of jpeg files of the moon (strange, as seems to work ok still when I run through planetary frames!)... Anyways, well done on capturing the 99.7%! Derek
  14. Lovely images, James! Well done for getting up and out at that time - it's never easy, but it's definitely worth the effort if it leads to images like these. Looking forward to seeing the timelapse!
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