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Showing content with the highest reputation since 04/06/12 in Posts

  1. 44 points
    i am well pleased with this. 15 x 1200 sec HA binned 1 x 1 8 x 600 sec OIII binned 2 x 2 6 x 600 sec S2 binned 2 x 2 the stars are from short rgb data for there color stacked in dss processed in photoshop cs2 it took 5 clearish nights to gather the data a couple of hours per night i chucked out half the images high cloud ruined them.
  2. 38 points
    I think time is just about up on Orion, I cant see me adding any more in the near future so its time to wrap it up for next winter. Ive added another 2 hours of non-moony subs to help with the noise. As usual Ive deployed the star hammer to knock back Alnitak and a few of the other stars that turn into ruffy bloaters when you develop the image. Some selective high pass and selective contrast enhancement was also applied, enough to perk up the Flame, HH and M42 - but leave the rest alone. So, as it stands: 2.5hr (in 600 & 900s subs), 2x2 bin, x6 panes (Ha) 130pds, Atik 383L+, NEQ6, SWCC Thanks for looking
  3. 38 points
    Following on from my mono image, here is the colour version. It was nice and clear all night and the moon wasn't above the horizon until fairly late which allowed me to capture another 6.25 hours in OIII to add to the earlier Ha, meaning this one adds up to 12.5 hours in 900 sec subs.
  4. 34 points
    I posted these on CN last night & thought I'd post them here on SGL as well: there are 2 or 3 other images on about the same level as these but I chose these 2 to create a couple of our "Somersaulting Saturns" for the website... Check out the website http://momilika.net/ & click on the Saturn icon & then go to the "Latest Saturns" link to see a bit more info but SGL should accept the .pngs at full scale...if not they'll definitely be full-size on our website! ps: The top image is from the ASI174MM & the bottom from the ASI224MC!
  5. 34 points
    I'm currently on 'astro-holiday' at Kiripotib in Namibia. First target on the list was (of course) the Carina Nebula. Below you'll find a (very) quick process of the 52x5minutes of data I gathered. Used a unmodded Nikon D600 with a 107/700 APM with Riccardi Reducer, mounted on Fornax 51 and guided by my Lacerta MGEN. Setup works like a charm! Quite pleased already with the result I must say, especially considering the fact I'm using a non-modified camera
  6. 32 points
    I have put together a few images which demonstrate in a nutshell how I get from raw input data to the panes I throw into AutoStitch64. It all starts with the AVI, I typically gather 1000 frames per pane. With the Solar Spectrum filter, even a single frame can show a good deal of detail. Carefully tweaking focus until sharpness is optimal is essential. A frame obtained today is shown below. Although it looks decent, this is not a good starting point for mosaic stitching. One reason is the fact that there is a distinct uneven illumination (or shading) visible. By taking flats this can be corrected. Various approaches can be used, I tend to defocus, take an AVI of the same length as the ones for the panes, and create a master stack in AS!2 (under image calibration). I often apply a smoothing filter (100 pixel diameter flat averaging often works) to get rid of residuals of sunspots or bright plage. A caveat is that dust bunnies are not well corrected for if you smooth the flat. Fortunately, the camera shows no sign of them (yet). Loading the master flat into AS!2 ensures all frames are corrected. Not that if you take AVIs of an ROI rather than full frame, you must create flats for that ROI. The result of flat-field correction is shown below. This looks more promising. I then stack 100 (typically) of the frames (letting AS!2 pick out the best ones). The result appears to be not much different from the previous, as can be seen below. Looks can be deceiving, however. If we apply Lucy-Richardson deconvolution (sigma = 1.15, 50 iterations works for these data) and unsharp masking (sigma = 1.15, strength 2.75) in ImPPG to the stack of 100 images, we get a very decent result. I frequently work with higher strength values (3.75) in ImPPG, as can be seen in this screenshot The parameter values used depend heavily on the optical system and camera used. I have recently found that the smaller sigma values work best for my current Solar Spectrum filter, whereas in my previous LS35THa and also SolarMax-II 60mm I tended to use much larger values of sigma for unsharp masking, and slightly larger ones for LR deconvolution. The reason for the small sigma value for unsharp masking in the new set-up might be that the contrast for large structures is good enough, and they do not need to be boosted, so I can focus on small detail. Just experimenting in ImPPG is the way to find what suits you best. The image above is the kind that I use for mosaic stitching. My procedure for that is VERY easy: open AutoStich64, click on the "open files" button, select all your panes, and sit back. Any tweaks of contrast after stitching is done in GIMP. Applying the same settings for sharpening to the flat-field corrected frame yields this: Result ≠ good The noise in a single frame just explodes. By stacking 100 frames we can increase the signal-to-noise ratio by a factor of 10 (square root of the number of frames stacked). I might also want to use a single pane as a detail shot. In that case I like to apply contrast stretching or (partial) invertion of contrast in ImPPG, not GIMP. The reason is that AS!2 outputs 16-bit TIFF files, and ImPPG allows me to work in 16 bit mode with the curves. The results of applying a sigmoidal curve to stretch the contrast in the mid-tones look like this: The exact degree of contrast stretching is entirely a matter of taste. One of my favourite contrast tweaks is partial inversion of the contrast. The aim here is to have the region outside the disk in positive contrast (but heavily stretched to bring out proms and spicule detail), and everything on the disk in negative contrast. To achieve this I create a convex curve with a single maximum near the grey level of the spicule layer. The original black and white values are both mapped to zero. I then insert an extra control point to set the apex of the curve at the grey level of the layer of spicules, or a bit above. This point is set to just below white (255) as output value to avoid saturation. The resulting curve is roughly a parabola, which I then correct with two additional control points on either side of the apex. I move these to make the curve on the right a bit concave, and on the left nearly straight. I then tweak until satisfied. The result looks like the one below, and has a 3D feel to it. A screenshot of ImPPG shows the curves used: Finally, I might want to turn the image into a pseudo-colour version. To do this I open the image in GIMP, and apply a series of curves for red green and blue to achieve this: The latter is done with curves that look more-or-less like this I will add more detail (including screenshots) in due course.
  7. 32 points
    Just had this image published in the BBC Sky at Night Magazine,
  8. 30 points
    Apologies to SGL'ers for essentially "cut & pasting" the CN text I've just posted here...I do think SGL'ers deserve their own thread comments but I'm tired & pushed for time here, so only a few alterations to that thread on Cn if you've just been there..! Hi all - spent a couple of nights down in the Mallee trying to find a bit of clear air.....the forecasts looked good but being brutally honest the seeing was nowhere near as good as BoM or SkippySky suggested - not that we place terribly much credence in any forecasts anytime tbh..! And just to be clear about things like "great air" etc that were bandied about on CN let me be frank herein - naturally all these appraisals are "relative" to each & every one of us...but there was no way whatsoever that the last 2 mornings qualified for anything more than "barely passable" seeing - I think we've been around long enough to know our own situations to a reasonable degree! Ok - with that "off my chest" (and I think it IS relevant when appraising the "possibilities" with this new camera) we were pleasantly surprised with the outcome on Saturn: Jove is a bit of a dog down here at only 38-39° & requires quite extra-ordinary seeing to deliver decent outcomes - love to shoot up North for a week or 2 but we're broke & I can't keep on using Pat's lappy constantly, so pennies are sort here..! Thus getting a decent Saturn with plenty of surface detail in very pedestrian seeing is quite an accomplishment & suggests this camera is a "go-er"...we've managed said with the 120MM-S before but without nearly as much histogram control that the software gain gives us with the 174MM. I have a lot more experimenting/investigation & queries re this camera, plus the new FireCapture beta program used, but I think the preceding paragraph is a good valid observation for starters... Of note is the fact that Pat's Dell is only a standard duo-core (with hyper-threading, thus acts like a 4-core to a certain degree) with a standard HD - we switched off the Wi-Fi & disabled Norton AV, cleared all surplus data off the drive & had no trouble keeping up the FPS...even at 200fps using 512X440 ROI on Jove. As said the Jupiter caps weren't worthwhile but the fps with Pat's lappy showed that this machine could take it...I want a super-fast replacement to my old dead lappy - which was a "fast-un" - but this works in the meantime! If we opened WinJupos etc during captures the FPS saved did lag behind the capture rate but caught up again pretty quickly before the avi finished its' set time-span.....so it looks like you don't necessarily need the fastest machines out there. We had only a couple of spots on the camera window which were most likely the result of me having the covers off for a lot of time trying to get an optimum imaging train set-up at short notice: seems like ZWO have done some work there over time :waytogo: ...I certainly don't think the (almost) 10 metres f/l was ideal in the conditions but that must count as another plus for the specific image... I'm making up a new imaging train & still want variability in the arrangement but think I might have an answer... Anyway, here's a Saturn with promise, plenty of bright spots visible on the disk & whilst I'd "love" some Jovian opportunities further North atm that's not going to happen...and in many ways surface detail on Saturn is much more demanding than great Jovian resolution so we're pretty satisfied with our first efforts - but a whole lot more trialling & also investigations/queries to be done! A big "thank you" to Sam at ZWO - without his generosity this would not be possible..! :waytogo:
  9. 29 points
    Just the right size for my focal length and chip. However you capture and process this galaxy , it remains a big scruffy ball of stars and hydrogen clouds. I have to say though it is possibly my favourite object in the night sky. You see this processed with so many different colour variations, it is tricky to get any colour in to the core at all. This image is a combination of data captured during 2014 and 2015, totalling 14.5 hours of exposure time. Altair Astro 6" RC and Atik 460ex. Captured in Sequence Generator Pro and processed in Pixinsight & CS5. Hope you like
  10. 28 points
    I've been waiting a very long time to make this post. My journey into astrophotography started nearly two years ago when I realised that just seeing beautiful objects in the eyepiece wasn't going to cut it.... I needed to show other people these wondrous things, and I couldnt keep waking my girlfriend up at four in the morning Being a total newbie (typical story, owned a Tasco refractor for about five minutes when I was too young to even point the thing) I burned through a half dozen unsuitable scopes on the way to my current imaging rig, a 102ED doublet APO. Even then, my first attempts failed dismally due to a total inability to polar align (house in the way) and no guiding setup. My first attempt was a pretty terrible M42, unguided, I could barely manage 30 second exposures on the HEQ-5, so poor was the alignment... I got something alright out of it with processing, but nowhere near the posters here. I resolved to improve. Then...I got a new job, all my time was eaten up for a whole year, but finally I am ready to start again. I've waited night after night, checking and rechecking my equipment, and tonight was a whole 10 hours of clear (hazy, moonlit but I'll take it!) sky... I chose the first deep sky object I ever saw, back with my AstroMaster 114 Hall-Newtonian (yes, yes I know, horrible) but it caught my breath even through such a mediocre scope.... Tonight I was back, with Canon 6D and SX Lodestar guiding, although STILL not properly polar-aligned so relying 100% on guiding to correct polar drift... amazingly this setup works very well despite being relatively cheap and low-tech. It's a lot of preamble for not a lot of result, but I couldn't be happier May I present, with a bare minimum of stretching, no darks, no flats and no bias..... M13. I'm happy with it
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