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alacant

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Everything posted by alacant

  1. Hi everyone This is a good one if you're short on time. Except having done an hour, you realise that the background is full of interesting dark bits. We found this by accident; all the bg stars seemed red and orange. Anyway, not really enough exposure for the darker stuff, but ok for the fg stars. Must remember to order some more patience from Amazon. Thanks for looking and do post your dslr efforts if you've had a go. 700d @ ISO800 ~2h
  2. Hi I think the imaging version of the C8 is called 'Edge'. If you've good enough atmospheric conditions, it maybe worth a look. The longest we go is 1200mm. With DSLRs, but only on the occasions when the atmosphere supports us.
  3. 1/4" 20 UNC Or just drill off the thread and use m6. HTH
  4. Lovely shot. I found quite a few more stars in your .TIF, helped in no small part by StarTools' latest Deconvolution module. Not sure if it's in good enough focus though. Oh, and I'm hopeless at colour unless someone is telling me over shoulder style. Cheers and thanks for posting.
  5. Yes, absolutely. Much better. For Andromeda, it's unfortunate you can't fit older Zeiss or Takamar lenses to a Nikon. Maybe you could look around for a Nikon fit 135 or 200 though.
  6. Hi The stack is 12032 x 8033 and over 500Mb. How did you arrive at that? You lost a lot of the galaxy. Maybe guide the camera to avoid overlap and try longer exposures with the galaxy centred in the frame? Cheers and HTH
  7. With conventional processing you can't, no. With StarTools, you most certainly can:)
  8. Sorry. I read 'GPU cc'. DUH! So, it's the opposite. You need 75mm between the cc and the sensor and you'll need to wind the focuser OUTWARD to reach focus. You'll need a 20mm extension tube Here is the GSO cc with the required extension tube and the typical focus position. With the gso cc, you'd be better off with the 130p; sensible focus position, better contrast and it's cheaper. Cheers
  9. Hi Maybe have a think about this... Say, instead that you wanted to shift your eq6, at the same margin. How do you think that would go? Cheers
  10. Hi Try also outward focus. The focus position of the 130pds is the same with and without the GPU cc, so the first question has to be, can you achieve focus through the d5000 without the cc? To answer this, simply remove the cc and screw in a m48 thread 2" extension tube to the t ring instead of the cc. If you can't then maybe you have the 130p rather than the 130pds. Please post a photo of the camera attached to the focuser and measure the length of the tube. Cheers
  11. Hi No theory, just hands on... We don't use apt but have found that using a focusing mask (FM) doesn't give you best focus when using a camera lens or -particularly the cheaper doublet- refractors. E.g. on our old Takumar and Tair lenses, the green and blue agree and focus well, leaving the red out of focus. A FM will therefore give a red halo around stars. Our 72ed is different in that it has the red and green in sync, giving blue halos. Conclusion, the FM will give you the strongest two out of three colours. The trick is to compromise. Use the FM mask to get close, then using a mid brightness white star, look -use your eyes- at the halo around the star. Focus manually until whatever halo you have disappears. It's a tiny amount. Reflectors fare better and the FM gives perfect focus; mirrors are perfect apochromats. Worth a try? Cheers and HTH
  12. Much better:) You've still gone very heavy handed on the choice of ROIs though. Go easy on the contrast. That is almost certainly where your unevenness originates. For second (an subsequent) AutoDevs, it's important to try different ROIs. Try the core only, one of the arms, a group of bright stars, a group dim stars including or not the galaxy... The possibilities are endless. Don't worry if you don't get it right first time. The beauty of st is that your data is always linear. Do your processing in any order. In the end, at last we've a viable alternative to the ancient levels and curves approach where your data was manipulated as a series of non linear files produced as a result of isolated unrelated procedures. Of course, if you're happier with the latter and it produces better images for you, stick with it. Cheers EDIT: even if you've overdone it, there are a couple of 'rescue' things you can do: But it's just as easy to wind back to an earler stage in the processing and redo it from there. your data remains linear.
  13. Hi If you are correctly balanced, that should not happen. Remember that there are two corrections needed to balance DEC, compared to just one for RA. How are you balancing each axis? Cheers
  14. Hi Point your telescope south at around Declination 0º. Try these settings:
  15. Make a mark on the lens of the original orientation before you adjust. But hey, they're around €50. Is it worth the hassle? If you want one for daytime use ¡cómprate otro!
  16. My photo is with the adjustment made and with the focus up against the physical stop. No.
  17. Hi To make a start, perhaps best to first... ...use the EKOS internal guider with SEP multistar, polar align, calibrate and then let it guide (anywhere in Cygnus would be fine) for at least 30 minutes. Take defaults throughout. Adjust nothing. Post -Iinks to- both the guide and kstars logs. Cheers
  18. Hi No need to open the lens. With the lens set conventional infinity against the physical stop, Unscrew each of three grub screws one turn each to loosen the focus grip. Next, rotate the grip only about 1/8 turn so that when tightened, it will propel the lens beyond infinity. Re-tighten by the same amount you loosened. On the 200, the green and blue are in close agreement, leaving the red out of focus. Using live view at 10x on a moderately bright white star, rotate the grip until there is a pronounced red halo. Now twist the opposite way until the red halo just disappears. Focus masks will not get you this close. You're close, but 5 minutes adjustment will allow you to make certain. That's it. HTH.
  19. Hi This with the latest ST v1.8.511. Apart from wipe using synthetic bias and flats, I stuck as close to the default values as possible. It seems that maybe the flat frames are not correcting the field too well and there are vertical bands which new dark frames may help with. Both succumbed to Wipe however. Not definitive by any means. Yours has more detail and colour, but as I thought, there is more galaxy to be had. HTH anyway.
  20. Hi That's the shadow of the camera's mirror. The star changes shape because the focus tube is entering the light cone resulting in 'D' shapes instead of circles. Fit longer springs and screws to the primary to bring the focus position away from the tube. If that doesn't cure it... If you are certain that you're collimated then the next thing to try would be substitute the secondary mirror. An astro club is good (essential?) For this. After that, rotate the primary relative to the tube to see if that changes the mask pattern. Cheers
  21. Refractors in general I believe. Certainly our 72ed and other camera lenses. The mask will get you close, but the final tweak is best done by a human. We find the opposite. I'd say that the second development ROi in AutoDev being chosen wrongly. Post the stack if you like. Cheers.
  22. Hi Lovely shot. The Russian lenses are very good, but I'd put good money on there being loads more galaxy in your image. Maybe don't be so harsh on the development? Here is our version, also with a tair3 and StarTools. Focus on our tair is a compromise; viewing a medium bright star on a large screen, move toward infinity until a red halo is seen around the star. Now back off until the red halo just disappears. Oh, and we find f5.6 is fine. Cheers and HTH
  23. Hi Set a lens to M and focus with your un-modified camera. Anywhere in Cygnus would be fine. Now without changing anything on the lens, mount it on the modified version. Set to RAW at -perhaps- ISO800 and take a 3-4 minute as you would normally. Post -a link to- the RAW frame here. Beyond this we can only guess as we don't know which camera is which. HTH
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