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Carl M

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Posts posted by Carl M

  1. Debayered the RAW's in IRIS and used only the red channel for stacking in DSS. About as far as I could stretch it without noise being too visible.

    Quattro 8s f/4, EQ6

    18 x 600s with a full spectrum Canon 1000D at ISO800

    Astronomik 12nm Ha clip filter

    Final.thumb.jpg.66f141cfc8d4f93b9aa5454705dffa26.jpg

    Might add some RGB to this once the moon is gone, but I do quite like it in mono.

    Thanks for looking,

    Carl

    • Like 15
  2. With such a bright moon and with it being so close to Rosette nebula I decided to give my much neglected C9.25 a run out. Had trouble trying to get sharp images with it in the past which must have been a cooling problem. Left it outside for a good 2 hours or more before checking collimation and focusing and it seems to have held up quite well. In the past I would leave it outside for a while, do a star test and I would see a heat plume.

    All images are the best 20% of 2000 frames; captured in Sharpcap, stacked in AS!2, wavelets in Registax and slight sharpening in PS. Captured with ASI120MC and the standard 2x barlow that you get bundled in with Skywatcher telescopes - which I hope to replace sometime soon.

    Gassendi

    GassendiC.jpg.e216b52974e5fd352e5ee8fdc2ead03e.jpg

    Copernicus

    Copernicus.jpg.99c7916011cf7b5489c9a338c67b9173.jpg

    Moretus

    Moretus.jpg.e0824d36d52158dcbe9b03888cd60eeb.jpg

    Rupes Recta

    1242676035_RupesRecta.jpg.ec111e31c7ef132f62f29dbf43fe1cc5.jpg

    Moretus and Clavius area (no barlow)

    SouthernLimb2.thumb.jpg.9eb84579c046afe0444f7dec1fe912fa.jpg

    and as a bonus, thought I'd attempt my first mosaic. Didn't expect it to come out well doing it manually but I got something at least. Next time I will use something like EQMosaic and do the whole moon, hopefully it stitches together a bit better. This was 9 frames stitched together in Microsoft ICE.

    terminator.thumb.jpg.cc922c31c1aca87dcbd769b4feda00de.jpg

    Thanks for looking

    Carl

    • Like 5
  3. Thanks all, I thought the darker dust seemed a bit red and the stars also seemed overly red which made me think there was a red cast to the whole image. Most images I saw the dust was more of a chocolatey brown colour.

    @Singlin I think your first post is similar to what I had in mind. I've been playing with levels and colour balance a bit more last night and I think I'm happy with this for now.

    M42v3.thumb.jpg.43626c43234734fda14f6a23274aad9f.jpg

    • Like 2
  4. I think you've done really well there with an unmodded camera, the long integration time certainly helps it seems. It's going to be my next target so couldn't resist having a quick play in Photoshop, hope you don't mind!

    GonzoRosette.thumb.jpg.bb53129d358875ace5497a7ea1e9b51d.jpg

    • Thanks 1
  5. I've never really had a proper go at the Orion nebula, but since it's above the house now at a good time in the evening I thought I'd give it ago. Still can't seem to get the colour balance right with the modded dslr and Astronomik CCD-CLS filter, it still looks a bit too red in my opinion.

    This was 2 hours worth of 5 minute subs at ISO800. 20 x 15 seconds for the core.

    Full spectrum 1000D, Quattro 8s on an EQ6. Processed in Photoshop.

    M42.thumb.jpg.d5da63029a124f15556cbb53b2042dff.jpg

    If anyone has any advice on removing the red cast I'd greatly appreciate it!

    Thanks for looking,

    Carl

    • Like 26
  6. Didn't have to wait too long for some clear skies to try out one of my Christmas presents - an Astronomik 12nm Ha clip filter. I was also glad for once that the moon was up so I could give the filter a good test. This was my first attempt at a narrowband image so found focusing a little difficult, don't think it's quite spot on. When processing I saw double diffraction spikes which suggests it was out by just a tad.

    This is 15 x 10min exposures at ISO1600, with just the red channel being used after stacking in super pixel mode.

    Quattro 8s on EQ6

    Full spectrum 1000D

    bubbleRonly.thumb.jpg.a99380d1b88ef0eadc7126ed4d2434fa.jpg

    Very pleased for a first go, could certainly do with some flat frames which will be done in due course.

    Any advice or criticism is appreciated. Think I was a bit heavy handed on star reduction, but I do like minute stars in mono images.

    Cheers,

    Carl

    • Like 5
  7. 1 hour ago, Adam J said:

    It probably is the filter to be honest as I get a slight effect like this on my CLS and thats with a 130PDS so nothing that should be causing chromatic aberration. My general rule is that I dont let it bother me unless its visible when viewing the image as full scale, pixel peaking is pointless who looks at a single star in an image?

    Yeah you are right Adam, I try not to pixel peak but collimating this f/4 has turned me OCD about star shapes - that's the only reason I noticed it :grin:

    Quick way to reduce the effect was to run one or two star reductions on the red channel.

  8. 9 hours ago, bottletopburly said:

    Great work carl?? Btw  Startools has some modules to help with noise if you weren’t aware  and it’s free to try 

    I may give Startools a try. I can do it in Photoshop too but the trouble is I want to bring out more dust as well as eliminate noise. Think for that it's best to just get more data, unfortunately had to throw away a load of subs from the end of the night.

    6 hours ago, tooth_dr said:

    Lovely! Great detail and star colour. 

    Cheers! Your Ha images with the 1000D are mightily impressive, convinced me to make a 12nm Ha clip filter my next purchase.

  9. First time taking flats and adding them to an image, they make processing a lot easier when the background is uniform. I don't think they were perfect but they've definitely helped. Will be making sure to take them for every image in the future.

    28 x 300s at ISO 800 - 2hr 20mins worth of subs

    36 flat frames, no darks or bias

    Dithered with APT and PHD2

    Full spectrum 1000D with Astronomik CLS-CCD clip filter

    Quattro 8s on EQ6 guided with ST80 and ASI120MC

    m45v2.thumb.jpg.3eb9a579cc268950b4a2cc55ca2b06bb.jpg

    Thinking of revisiting this soon to get some more data and eliminate some noise, but pretty pleased with what's there in 2 hours and 20 mins.

    Thanks for looking,

    Carl

    • Like 17
  10. Could be internal reflection, but then I'd have thought the bright stars would probably exhibit a bit more of this effect.

    This is quite a close crop mind, but it's certainly visible in full frame. Other thing to note is that the coma like tail moves throughout the image. Presumably the result of the coma corrector trying to correct it maybe?  This is the full frame 5min sub.

    fullframem45.thumb.png.b3a3cb34c33f22abdc39895916b680b4.png

  11. I am sure it is the CCD version of the CLS filter, that's what it says on the filter at least. I always focus with the filter already in place since it's the clip in one.

    I went back and looked at some images I took with my C9.25 which was with the same camera and filter, these also has the same red fringes around stars. This should rule out the coma corrector and the scope being a problem I guess?

  12. So I've been having problems with my stars not being perfectly round, most of that in the past I put down to collimation. However, now I believe that something else is at play.

    On most stars it seems like there is a chromatic abberation type effect, in particular it seems to be the orange/red stars that appear to show it worse. My camera is a 1000D full spectrum modified (clear glass replacement) and Baader MPCC with the Astronomik CLS CCD clip filter installed, which I thought included IR cut. The red channel seems to be the channel that shows the fringing, blue and green channels the stars are round and not bloated. Here are a set of images from a raw 5min sub to try and show the effect. It almost looks like the fringing has not reached it's focus point, which gives the appearance of the star bloating. Since it is only apparent in the red channel, would that point to IR?

    bloatRGB.thumb.PNG.14da8895afa9ab677708bdac9cde049a.PNG

    bloatR.thumb.PNG.b822804626687cd815789dcf39b3d832.PNG

    bloatG.thumb.PNG.e337a571e0e00e8b00b0d60e81992897.PNG

    bloatB.thumb.PNG.9c8a5d5996907a258fa72ae1235d429e.PNG

    In a single image it doesn't look so bad, but after stacking the fringe becomes worse. I'm aware there are some techniques that could reduce it in post processing like this one which I am going to try http://budgetastro.com/micro/articals/red_halos/red_halos.html

    I would much prefer to combat the issue at it's source though, if I can find out what it is! I'm going to borrow my old unmodified 1000D from my sister to see if the issue still remains.

    Any suggestions on what it might be?

    Cheers,

    Carl

  13. 5 hours ago, Adam J said:

    Very good, the combination of a F4 newt and a dslr works well.

    It's starting to look much more promising now that collimation seems to be sorted. Next hurdle is post-processing, this time I at least managed to keep some star colour without sacrificing the colour in the main object too much. Slowly but surely making progress!

  14. Clear nights are coming thick and fast now!

    34 x 300s  ISO 800 - 2hr 50mins total exposure

    Dithered with APT and PHD2

    No calibration frames

    Full spectrum 1000D with Astronomik CLS-CCD clip filter

    Quattro 8s on EQ6 guided with ST80 and ASI120MC

    witchbroomW.thumb.png.e16407e453f70fa6f44d9ebc3f239411.png

    Would have like to have gotten some more of the fainter details to come out, but I think it might need some longer exposures. Can't seem to go much higher than 5mins without the background being over exposed.

    Thanks for looking,

    Carl

    • Like 9
  15. 13 hours ago, bodgebarker said:

    Hi Carl 

    someone with a Quattro . Would you happen to know the model number of the stock focuser, I can't find out anywhere. Trying to make sure the Rigel systems motor will fit. Rigel don't seem to reply.

    I'm not sure on the exact model number I'm afraid, this focuser from FLO is the same as the one fitted on the Quattro I believe.

    9 hours ago, michael8554 said:

    Hi Carl

    Great image for a 1000D, the Dithering has really worked on the background - how much did you Dither?

    Michael

    Thanks Michael. I think I just left the dithering at the default amount, I don't remember changing it; but here are some screens of the settings I use.

    APT.PNG.38145fc14cc87b73131c5731de5b5be9.PNGPHDDither.PNG.93d4929a4d30e5e4ec07659c11999a8f.PNG

     

  16. 2 hours ago, graemlourens said:

    Great job Carl!

    I am a little color blind so please take my advice with a great portion of margin of error...

    I though that it first is black and white :) only on a second look i saw it is actually color (thats my bad!). I quickly took it to Photoshop and checked out what could still be pulled out color wise. It does get noisy pretty fast, but with a few quick masks & saturations, its easily possible to still pull out a lot of color in the galaxy, assuming you're not going to be printing this large scale...

    The detail & sharpness are very nice, and i couldn't say anything bad about that...

    Kind regards, Graem

    You are right Graem, it's not got a lot of colour just a tint of blue. Colour balance with the Modded DSLR and filter always seem to be a bit of a struggle because it starts off overwhelmingly red after stacking. Normally when I go back and add saturation after processing it also affects the background colour (which I assume is what the masks you are referring to are for).

    I would love to see any changes you have made so I can look for improvements for when I inevitably go back reprocess again. If it helps I could post the .tif here or the raw stack for you.

    Cheers,

    Carl

    • Like 1
  17. Finally a clear night without a capricious breeze where I could actually get some imaging done.

    This time M31, which I'd been putting off for a while because I can barely fit in in the frame and because I'd heard it's a big of a pig to process..and so it was. Anyhow, I got it into a position where I'm happy to post it.

    34 x 240s ISO 800 - total 2hr 16mins

    Dithered with APT and PHD2

    No calibration frames

    Full spectrum 1000D with Astronomik CLS-CCD clip filter

    Quattro 8s on EQ6 guided with ST80 and ASI120MC

    basic3a.thumb.png.038925b93bdebe1a345e7ba0d92a6289.png

    Think sometime in near future I will give it another process, but for now it'll do. Next time I will try and do flats to see if it helps create a more uniform background, that seems to be the main problem when processing.

    Thanks for looking,

    Carl

    • Like 14
  18. You could be right there, it's very difficult to tell... should have taken an image in the top left without filter and the lines may have been a bit more apparent if they are there.

    If that would be the case then I'd assume that the diffraction spike is coming from the secondary not being centred and the light cone clipping a bit of the focuser. I did have a single diffraction spike problem before without the filter, perhaps since then I've recentred the secondary and made the problem worse or better which has changed the pattern of the spike.

    I hadn't thought of that, thank you - time to recollimate!

    • Like 1
  19. Hello there,

    A while ago I posted a topic with the same problem, and initially I thought something was up with collimation or mechanically. Previous thread:

    However, now I have found the problem to only exist when my Astronomik CLS-CCD filter is installed into my Canon 1000D camera. The only thing I can seem to do that changes the effect of these spikes is move the bright star into corners of the image. When I remove the filter, the issue is no longer present. Obviously I could just image without the filter, but I don't think I will be able to expose for as long without LP saturating the image.

    diffraction.png.8c41c2188e7a79fffee0164851b30c63.png

    Any ideas as to what else could cause this? I'm struggling to think of anything the filter is possibly doing to the light path to cause this artefact, other than possibility of some sort of internal reflection. I've even intentionally made collimation bad to see if the spikes changed shape compared to collimating properly, and nothing changed. It does seem as though something could be intruding the light path, but I can't figure out what it would be and why adding a filter would create the effect?

    I appreciate any suggestions!

  20. That's really helpful thanks!

    I wish I'd also collimated the primary with my laser when I was out there now to see if I got the same result as these two horsehead images show. All my other images have these same two additional spikes on bright stars when I was using the laser for collimation. Then it would have pretty much confirmed it to be the focuser intruding into the light path. It may also explain why the shadow of the secondary shifted when I collimated the primary using a defocused star while outward focusing, then when I defocused the star again using inward focusing it was out of collimation again.

    I don't think the angle means much. If you rotate the camera in the focuser the spider vane spikes will move position, but the additional spikes stay static. I diagnosed this while I was out there. Also, when I took the image with the spider spikes intersecting the additional spikes the additional ones were coming from the same axis as where the focuser was. I remember meddling with the vanes while I was out there because I thought it might have been them! Seems as though all aspects point to the focuser :D

    rotation.thumb.png.50d8f673739129c00ea522b6c982a159.png

  21. 20 hours ago, Adam J said:

    Highly unlikely. What you are most likely seeing is the results of a rubbish laser diode. Very cheap laser diodes have terrible beam divergence in one direction due to their construction. It gets worse the more power you put through the diode, try dialing it down to the minimum brightness setting and you should get a nicer spot....

    However if its this piece of rubbish or another derivative of it then you may still get that effect even on minimum power:

    http://www.rothervalleyoptics.co.uk/skywatcher-laser-collimator-1252.html

    Dont believe me then place it on a flat surface turn it on and fire it at a wall about 4 meters away, you will see it produces a cross pattern as its a rubbish diode. Then consider that the effect of bouncing it off the primarys curved surface is to enhance that effect and you will understand why you are seeing what you are seeing.

     

     

    Hmm you are correct, not the secondary mirror itself. I pointed it down just the open end of the tube to the primary and still saw the pattern. If anything it seemed like the primary was too far up the tube as the mirror wasn't touching all of the locking screws, I'm not sure if having the primary too far up the tube would cause issues? I'm fairly positive that the focuser hasn't obstructed the light path before but will check again on next clear night.

    I've also had two additional star spikes like this before, I wonder if these issues are connected to the same problem? Close up it looks like there may be more than two additional spikes, they just happen to be closer together unlike the first image. Quite hard to tell. 

    58dc19db044e8_mirrorspike.thumb.png.4e8e6a553e16b8053d8e6dab2a1dd5d3.png

    Spider vanes are measured and all the same length, last thing to check is for the bent spider vanes. Can't do much to check any changes until the some clear skies come along!

    Thanks for help once again.

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