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almcl

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About almcl

  • Rank
    Star Forming

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  • Gender
    Male
  • Location
    Telford, Shropshire
  1. New Zealand Astronomy

    We're off to NZ next week for a holiday. While there we are going to try Big Sky Start gazing on Mount Cook. No idea how this will turn out and, only being there for one night, the chances of a clear skies are not great, but will report on return.
  2. Polar aligning an ALT AZ EQ6

    Thanks, Wim. Glad to know it's not just me! I've tried the offset technique you describe, also smaller and smaller 'untighten-shift-retighten' increments but probably down to operator ham fistedness these aren't always repeatable, although on some days we get down to less than 5' PA error, others it can be 15 or more.
  3. Polar aligning an ALT AZ EQ6

    Thanks, Freddie, yes I have considered some grease or possibly a slip ring cut from a large milk container (got these in several places, now) between the tripod and the mount base... Might have to try this.
  4. Polar aligning an ALT AZ EQ6

    Sorry if my description wasn't clear, I am not slackening the clutches (honest!) but rather the fork tightening knobs (as per the SW instructions): and the primary locking shaft (the one that clamps the mount to the tripod). With it tight the azimuth adjustment knobs (arrowed in red below) struggle to change orientation : The 'new' reticule makes any movement pretty obvious, but tightening the locking shaft frequently produces movements like that of the two black dots here:
  5. Been using my ALT AZ EQ6 for some months now and love the belt driven quiet movement and, when well polar aligned, the guiding accuracy is pretty good, too. One thing however is a problem. To adjust the position when polar aligning (has to be done every session as I have no permanent set up) I find it necessary to undo the clamps, so that polaris can be moved to the appropriate point on the circles (new style SW reticule). So far, so good. The problem that now rears its head is that tightening the clamps moves polaris out of the carefully set position, sometimes by quite monumental amounts. This is most noticeable when tightening the primary locking shaft, which absolutely has to be slackened or the AZ adjustment bolts don’t achieve anything. Not sure if this is a ‘feature’ or if something is wrong with my mount assembly, but would like to know if anyone else suffers the same issue? Or better still has overcome it?
  6. Halos on Astronomik Ccd clip

    Not entirely sure of the ground here, nor of what you have in the imaging train, but I have found it is quite difficult to get the red and blue at the same focus point, once the Canon IR blocking filter is removed. One suggestion I've read is to concentrate on focusing the red as sharply as possible (may not be where the Bahtinov says it ought to be) and accept that a slight blue halo may result, the theory apparently being that a blue halo is less intrusive than a red one?
  7. What is this? Can I buy one? Can I make one?

    There's a web site which gives details of how someone made one here: http://www.astro-images.de/miscellaneous/misc_sun.html In German and the translate function in my copy of chrome leaves a bit to be desired but the essentials are there...
  8. Using ASPS and APT together

    Thanks for that! I'l give that a go next clear night (might be a while, we've just had 4 in a row).
  9. Started using All Sky Plate Solver recently (thanks to Steppenwolf for the heads-up on that) and it's working really well. Discovered its compatibility with Astro Photography Tool (which I've also recently started with). Finding both very good but having difficulty getting my head round the multiplicity of functions they can perform together and wondering if the community has any thoughts to share on how to achieve the following. I want to use a sub from a previous night, already solved, and get the Pointcraft or GoTo function in APT to position the scope back on the target, in a similar position to the earlier sub. Pretty sure this ought to be simple and possibly automatic, but somehow, when at the scope, in the dark, I can't find the right buttons to click in Pointcraft or get confused by GoTo and GoTo++ or find the scope repositions itself to somewhere entirely different. If someone has a foolproof check list, that would be fantastic but any pointers would be welcome.
  10. Think Ken is referring to this: https://openphdguiding.org/man-dev/Trouble_shooting.htm#Star_cross_test Star cross test is described about half way down but the rest may be worth a read, too.
  11. Ha filter with modded dslr. 7nm or 12nm?

    Here's a heavily cropped 10 sec Bahtinov exposure at ISO 1600 using my Astro modded Canon 700d with a 12nm Ha CCD EOS clip filter. It's definitely not as easy as normal, but reasonably do-able, I think?
  12. ngc7023 iris

    Are you post processing with Startools by any chance? If so, then it might be worth winding down the red reduction slider in the colour module. I found this a rather challenging DSLR target last year, been meaning to go back when it comes back into view from my garden, be interested to see how you get on with more subs?
  13. Astro Crossword

    Many thanks for that, Kerry. Looking forward to solving it (eventually!) Think the clues for 9 and 10 AC in the pdf, are actually numbered as 2 and 3?
  14. What could be causing this?

    This looks like 'walking noise' . There's quite an amount of drift between frame 1 and frame 30 something and it looks pretty linear, so any hot pixels can get 'smeared'. Don't think flats will help but dithering might?
  15. Cataracts

    I am a bit further along the path, having had a cataract operation on one eye about six years ago. The result of this is that one eye is now 'bionic' and sees clearly at long range while the non-operated-on eye is good for close-up work and despite being dimmer, is great for making out subtle variations in planetary markings. Being able to see distant things clearly, without glasses, almost immediately following the procedure was a welcome experience, and while I wouldn't recommend cataract surgery as a recreational activity, when or if the time comes, it isn't too bad an experience.
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