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daneel

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Everything posted by daneel

  1. I love the cobalt blue central part of the nebula, that really is stunning, nice palette choices and crispy contrast. Ramin
  2. Breathtaking, love the detail on the obscuring dust. It's a great interplay of figure and ground, those dark nebulae are worth the extra time.
  3. Nice one, you've caught the structure nicely.
  4. That's lovely Gina. Can't wait to see your mosaic.
  5. Amazing image. Devon's not just about cream teas is it?
  6. Hi Ant, Apparently it's a tricky object visually. The deep sky observing thread below says you need "low magnification and something like a UHC filter": http://stargazerslounge.com/topic/152068-magnification/page__hl__+cave%20+nebula#entry1531308 It's really dim and therefore well named; I couldn't see a thing with a 10 second exposure while aligning on the target. You usually see something with the 383L after 10 seconds, even faint galaxies, but imaging this one was an act of faith. I guess that's why the image required about 17 hours of data. There are some juicy targets coming up in the East, so itching to try a new target.
  7. Knew it was chilly last night, power on cooler was just 10% to get to -10 C. Ha 48 x 10 minutes (red) OIII 27 x 10 minutes (blue) SII 27 x 10 minutes (green) Celestron 80 mm f 7.5 Atik 383L+ Stacked in MaximDL (median combine) Two histogram stretches in Pixinsight, then individual bands stretched in the curve tool
  8. After the clear night last night I thought the image was deep enough to post. Scope: Celestron 80 ED 80mm f 7.5 R: 29 x 10 min H alpha G: 29 x 10 min S II B: 16 x 10 min O III Aligned and stacked in Maxim DL processed in PixInsight (DBE background subtraction, histogram transformation and two stretches with curve transformation.
  9. Thanks for your suggestion Olly I loved the M27 image you posted recently. Ten minutes seems like a bit of a gamble here. Clouds, satellites, and aeroplanes (we're under one of the Heathrow stacks in Amersham) are another kind of noise that increases linearly with exposure time. But I'll have a go when it clears. Also do you have equal exposure time for each wavelength, or give, say H alpha a bit longer because it has more of the structure in the case of M27? Le Grange is on my list of things to do before I pop my clogs, so hopefully I'll get to learn from you first hand. Those images were useful Mick, thanks for showing some of the combinations. I suppose the palette for narrowband is really just a matter of taste. Ramin
  10. At the risk of sounding like an advertisement my QHY5 finder guider package from Modern Astronomy fixed all my guiding problems. I prefer using the computer to look through the viewfinder rather than craning my neck at awkward angles. I've never had a problem finding a guide star even with the gain at 50% because the field of view is so large. The camera sensitivity is adequate even at exposures of 0.5 seconds which I use for guiding. Now with Maxim DL I plate-solve the guider image and use that to sync the alignment. The I can click on an object in the guide image and slew to that exact point. I'd definitely recommend a finder/guider setup.
  11. Added some more data from last night and annotated the image in PixInsight. Managed another 7 x 5 minute subs in each band but have to admit that I nodded off at 2. Woke up to find the guide star had disappeared at 4:30 as it had clouded over. Dashed out to shut the obsie worried that it might be raining but fortunately it wasn't.
  12. Flats were worth it, that's a gorgeous image Gina. I use a T-shirt too!
  13. That's beautiful Carole. It was definitely worth spending time re-processing this image, you've teased out the structure very nicely. Ramin
  14. Tried my first Hubble palette image of the Dumbbell. Clouds and short nights limited the exposure time, but managed these over two nights: 10 x 300s Ha = green 4 x 300s OIII = blue 4 x 300s SII = red There's a sort of diagonal grain across the image. I'm not sure if this is because my flats weren't right - I did flats for each filter. The image was taken at a set point of -10 C, and so were the darks. It's interesting that a lot of stars don't show up in OIII but they do in Ha (not surprising!) and SII (more surprising). The background OIII looks like more than half the stars have been extinguished. All the fine structure's in Ha, OIII is more diffuse and SII is very faint, but you can see the apple-core structure clearly. I'll add more light when the skies clear, but would appreciate help with removing the diagonal graininess, and any other tips of course! Thanks, Ramin.
  15. I recommend getting APT which is an amazing piece of software designed specifically for DSLRs. Then you can connect to your laptop and control almost any aspect of your images. I think it's written with EOS cameras in mind e.g. it can read the temperature of the camera and write this into the raw image file (useful to make sure your dark image temperature matches your light image temperature). It can connect to PHD guiding software to dither images, etc. and it's only 12.70 euros which is well worth it. http://www.ideiki.com/astro/ I also found a mains (12V cigarette plug) battery pack from astronomiser very useful because I often found I forgot to charge my battery: http://www.astronomiser.co.uk/canonpower.htm If you want to get some infra-red nebulas such as the Rosette, you might want to get it modded too. Astronomiser does it for 120 quid, or you could try it yourself.
  16. The NASA TV app is showing the transit live. Although I gave up on iThings and I'm watching NASA Edge http://www.ustream.tv/nasaedge on my linux box. That's from the top of the volcanoes on Hawaii, above the clouds. And the general page is http://www.ustream.tv/nasahdtv.
  17. Here's my first attempt at M51 with the new gear. I used a 2x Barlow which, in retrospect, was probably a mistake. With 1.25" filters the setup showed vignetting about half way across the field of view (80mm scope is f7.5, FL 600mm). Steve warned me and as usual I should have listened. Perhaps the 2" filter$ would have been better. 25 L 5min subs 12x R, G, B 5min subs Stacked the R, G, B subs together, then the L subs together in Maxim DL then LRGB-combined in PixInsight. Then colour corrected (tricky to get the right RGB weightings), removed vignetting with DynamicBackgroundExtraction and did a final set of stretches with the curve tool, along with a bit more colour correction.
  18. I tried both DSS settings (RGB and individual channel calibration) and it doesn't seem to make a lot of difference. The next time it's clear, assuming it's ever clear again, I'll try removing the filter to see if that's the problem. Thanks for your help Tim.
  19. All of my images with the filter are coming out of DSS with a bright blue background, this is the raw image: http://dl.dropbox.com/u/9812713/blackeye.TIF The histogram for RGB shows that red is shifted well to the left of green and blue. Is this a problem with the way I'm using DSS or just a result of using the Astronomik CLS filter?
  20. Arthur Eddington who pioneered many of the ideas in modern astrophysics (explanation of Cepheid variables, the idea that stars are held up by light pressure, test of light-bending in the gravitational field of the Sun...). He also popularized the science of astronomy which is why many of us are on this forum today. Avicenna who grounded science on observation and experiment and founded so many sciences, in particular medicine (testing medicine, quarantine, hygiene, benefits of exercise), Physics (motion in a frictionless vacuum never ceases, finite speed of light) and also Astronomy (stars are self-luminous, observation of a transit of Venus), Geology (mountains are upheavals of the Earth's crust). And he was Persian too.
  21. Great suggestions, I'll try all of them. Got an hour each of M3 and M13 last night so will use PixInsight on those and try the white balance trick today. And did 20 darks before hitting the sack. Thanks!
  22. I'm finding that a lot of my images have a blueish tinge because of my light pollution filter. For example the image here is 3 hours of 5 minute ISO 800 subs stacked in DSS and processed in PixInsight taken with an EOS 1000 (un mod-ed) with an Astronomik CLS clip filter. I used 3 darks, 15 flats and 15 bias images. Is there a standard way of removing the blue-ish tinge other than playing with the blue light curve? Also I noticed there's rotational symmetry in the background noise. I suspect this is caused by the hot pixels rotating in the image over the space of 3 hours but would have expected the darks to remove the noise. I took the darks at the end of the imaging session so the temperature should be the same as the last few images at least.
  23. I've got a mark III which I've used for solar imaging with a Canon camera. It works pretty well. I've used it for visual too and the optics were pretty sharp, although the eyepiece is pretty heavy when combined with a diagonal. The click-stops feel good. Never seen a mark II for comparison.
  24. In case you haven't sorted it out already it's CTRL-1 to slew to the selected object and CTRL-3 to send an alignment correction to EQMOD. In Stellarium Scope you'll see three ports listed at the bottom where your PC running the server will listen for commands. This means you can run Stellarium on another PC (somewhere warm!) and connect to the telescope-connected PC via your network. Let me know if you want more info, happy to help. Ramin.
  25. I've put my back out. I put off coming until today thinking it would be better but I'm still shuffling around. So if places are tight someone else can have my pitch. And I booked evening meals tonight and tomorrow night so someone can have those too (if you like curry!).
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