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Dave 2112

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Posts posted by Dave 2112

  1. On a similar note I found a laptop near the base of the scope made for bad AP, eventually figured out even the night vision colour setting in carte du ciel was bright and close enough to cause poor images. Ended up getting a 3m usb cable and keep the laptop as far away from the scope as possible

  2. well i cant get DSS to stack my comet. i have tried so many times. different captures over two nights. just now it looked like it was doing a stack and at the end it said, no picture to save.  i used an ED80 one night and a ED120 the other. i did raw subs of 120 secs 

    I had that problem, I'd moved or renamed the location of the output folder so it wouldn't create anything to save. Might be worth a check in the output tab?

  3. It makes a good start to treat all such theories as ``effective’’ rather than ``fundamental’’

    Its been a little while since I did a philosophy module as part of a non-philosophy degree, but that's how I remember it being described. Something along the lines..."I see that A+B = C" so I come up with the theory A+B=C. And its fine until X comes along and points out if A+B happens while D is present the result is E. So being a theorist I don't simply fall into an "I'm right you're wrong" argument, instead I thank them for the input and opportunity to refine my theory to "If D is not present, A+B=C". 

    The great thing about theories is discussing them can be entertaining, enlightening and endless. But the best thing about them is they aren't laws, you can modify and improve them. A sound theory is never going to be wrong, but it might be made more likely to be right.

    • Like 1
  4. To me, that seems to be wandering into the world of philosophy (lets face it...how many jet aircraft have been built as a result of philosophers arguing???).

    Wasn't it Aristotle who theorised men have more teeth than women? Since he successfully argued it must be so (for reasons I either forgot or never bothered reading) it was accepted men did indeed have more teeth than women. If only he bothered with a simple experiment of counting teeth...

    To me that pretty much sums up theories...they are so much more convincing if there is at least some attempt at providing supporting evidence, otherwise its just philosophy, and even great philosophers can be wrong.

    • Like 1
  5. Not sure if its more or less length, still working this stuff out too. I'm setting up a Skywatcher finderscope with QHY5 (and some youtube help) and haven't got as far as testing it tracking, but can get focus without any extension.

    Might be worth asking Skys the Limit. I've had some stuff from him in the past, very nice guy and he's likely to have an idea of how to make it focus.

  6. After much experimentation this evening the options that seem to work best for me are definitely Kappa Sigma (not median), per channel background calibration, everything else default. Used DSS 3.3.4 and images taken with a 100D.

    Marking the comet doesn't seem to make any difference I can see, adding darks keeps the noise down. I had the star detection as high as I could get it on 10 x 30s at 1600 ISO, and adding more data just increases noise around the comet without adding detail to the tail. A very purple image came out, fiddling with the levels, upping the saturation to 20% and a curve like this seems to bring it back. I keep reading you should do the colour stuff in PS, but my PS knowledge pretty much stops right after "click here to install".

    DSS comet

    Might be able to tweak it further and end up much better, might even read the help files. :smiley:

    • Like 1
  7. Excellent, thanks! I see you did the sensible thing and read the manual, I just did the usual...steamed in and pressed buttons.

    When I get back home I'll double check the settings for Kappa and RGB and let you know. Also I was using DSS 3.3.2 although I have just updated to 3.3.4 not sure it makes any diffence to the final image though.

  8. Hi Alex,

    Stacking comets seems a real test of patience, almost makes me glad they are rare events.

    I couldn't get the comet stacking option to work in DSS. The reticule would lock on to every star but wouldn't lock on to the comet and all stacks ended up as large blobs. In the end I used the edit star button to remove every star in one sub as an attempt to make it lock on the comet but it still wouldn't. I stacked it anyway, 10 subs, with darks, didn't compute offsets, stacked using the kappa sigma option and left everything else to default. The end result was very washed out, but I saved it with no changes and even my total beginner PS skills got the colour back. It ended up like this...


    Star might be a little egg ish, at the edges particularly, but its brought a bit more tail out and reduced the noise. I might have another go with more subs when my patience levels build up a bit.

    • Like 1
  9. You got some good tail in there. Funny though, years ago as a kid seeing thing on TV like Sagan's Cosmos I remember thinking...it would be great to see a comet. Now a relatively short time later we're photographing them from our back gardens. To see it is great, to get a picture of it with hobby equipment....well its amazing we can even do it, never mind wishing we'd done it better. :smiley:  

    • Like 2
  10. I had a load of trouble stacking this in DSS, I couldn't get the reticule to lock on the head of the comet and every stack looked like a huge blob. I ended up removing all the stars I could using the "edit stars" button, stacking without using the comet tool.

    Comet Lovejoy (2) (800x534)

    and no matter how much I fiddle with the image size in my gallery it still posts a tiny version.

  11. Thought I'd share this before I call it a night. I might have taken around 300 images of this tonight and will have a go at stacking and processing tomorrow.

    Its 60s, 1600 ISO, unguided, unmodded 100D in a 200p on EQ5. The wind didn't help much but the moon hadn't risen and for once everything seems to work. Also the first time I've used APT, what a great piece of software that is.


    And one day I'll figure out how to make images in my posts look a little bigger.
    • Like 7
  12. Hello all,

    Thought I have a walk out in the snow and have a quick go at the moon. Initial impression was drat, managed to get a lump of something on the sensor but it looks like I might have got a satellite or shadow of going across the moon. Here's 3 shoots, taken continuous at 1/80 shows a little black dot heading towards sea of crisis. Too small to be a plane, might be a weather balloon? Any other suggestions?

    IMG 0143

    IMG 0142

    IMG 0141

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