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steviemac500

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Posts posted by steviemac500

  1. Hi, I am interested as to people's thoughts on this. It's a 4 panel mosaic shot over several nights. Now, I know that most M31s are quite heavily blue but my data didn't have any in the galaxy but there is definitely blue in the image as its quite obvious in some of the stars. I read that in reality there are very few blue stars anyway and the more realistic colour is towards what I have here? I'm not 100% convinced but would be interested in what you think. Please ignore the pinched stars and the slight misalignment, I'm not quite finished and was going to add some HA in as well. Hi-res link below.

    https://astrob.in/wmpbtl/0/

     

    Image25lce.jpg

    • Like 6
  2. 11 hours ago, Stub Mandrel said:

    I'm afraid there's still something really wrong with that image (I hesitate as I have never produced anything in this league).

    This is a crop from centre bottom, the fault should be self-evident:

    image.png.c13911eee89eecd4065dc1075b849fa4.png

     

    Basically - two panes haven't been properly aligned.

    Yep, I see it now, can't believe I missed it but in fairness you have to look pretty hard or be looking for something anyway to see that!! I never noticed it first time round and I don't think it detracts from the image if you're not looking too hard. At a loss to explain it though as APP normally is faultless. Don't ever hesitate to offer criticism though otherwise how do we learn and this will be something I will scrutinise more in the future,

    Still, AN have published it so I am going to remain happy with that! :)

  3. A widefield shot of the Crescent. This is a 6 panel mosaic consisting of 5hrs in Ha and O3 in each panel giving a total integration of 60hrs. The mosaic was constructed in APP and then processed in PI minimally with a little noise reduction and then colour combined with the standard mix. I added the Ha layer back in PS to bring back some of the detail. I have attached the Ha as I like it too!! Hope you like them, C & Cs welcomed as always!

    https://astrob.in/mcv66q/B/

    Steve

    mosaic_ABEdeconmltstr.jpg

    v4.jpg

    • Like 9
  4. 8 hours ago, dave_galera said:

    Beautiful image, well captured and worth the integration time.

    I use StarNet++ on these type of images to remove the stars, then work on the resulting starless image to bring out details in nebulosity etc.......when finished add the stars back in which is dead easy to do in PI using PixelMath. This way processing the background detail does not effect the stars.

    Thanks for the comment. Could you explain the procedure for adding the stars in with pixel maths please?

  5. This is my last image before heading back to the cloudy skies of Scotland for a few days. Biclolour rendition - 10hrs in each of O3 and Ha. I've tried to minimalise the processing this time and used my Ha as a final layer to add back in the detail.

    ****No stars were harmed in the production of this image!!

    @wimvb the Starnet++ module is very good. I tried it on this image and the results are excellent, it just didn't suit this picture.

    Thanks for looking.

    Steve

    V1.png

    • Like 5
  6. 6 hours ago, wimvb said:

    @steviemac500, I just had a play with the image you posted. I created a star reduced and a starless version (starnet++)

    combination.thumb.jpg.89c29d457d136156d3b75b999647af6f.jpg

    I think that your star reduction didn't work because of the mask. I created a ring mask by combining two ordinary star masks:

    A. Noise threshold = 0.5, Layers = 6, Large scale/Small scale/Compensation = 2/1/2, Smoothness = 10, Aggregate and Binarize checked

    B. Same settings but Large scale/Small scale/Compensation = 0/1/0 and smoothness = 3. Strengthened this mask by bringing in the white point somewhat.

    Then pixelmath to create the ring mask: A - B

    Morphological Transform: 3x3 element, Morph. Selection, amount = 0.5, selection = 0.25, iterations = 8

    The starless version was created with standard settings in starnet++ on the original image.

    Combined with PixelMath, applied to the star reduced image:

    iif((X()+Y())>1, $T, starless)

     

    Thanks Wim, I’ll have a look at the other file later. Your mask generation is very interesting, I don’t understand it, but it’s interesting. Why the 3x3 element, everything I’ve read has said to use a 5x5? 

    Funny, I like starless nebula images but for some reason in Cyprus, no one else does! 🙄

    By the way, what language is that bottom line written in and where do you go to learn it?

    • Like 1
  7. @carastro, sorry I wasn’t being offensive, I was trying to be funny about how this post kept going round the same conversation.

    Morphological Transformation is usually used to dilate or erode stars. It can create a splotchy effect with the filaments present if it’s used badly, as in my image. I tend to use it to draw more attention to the nebula but I may not anymore. 😀

    • Thanks 1
  8. 8 hours ago, carastro said:

    The final version, (without the noise reduction), looks great.

    Carole 

    Thanks for the support guys, the learning curve as ever remains high. @Xplode, sometimes you need a shove to refocus and quit bad habits, I may lay off MT for a while 😉. @Datalord, thanks for your help and finally @carastro, just to be clear, it was the Morphology causing the artifacts not the noise reduction, in case anyone else was wondering. 😂😂😂 

  9. 23 minutes ago, Datalord said:

    second.

    image.png.9a43c87cf7f17f4ce3491e29fed6a941.png

    I know it is tiny stars, but I think they might become too small. That's why I would like to see how big they are before you morph.

    It is quite bad when you pixel peep 🙄. I’ll have to have a look at the data later as it’s on the on the other computer. I may just forgo MT altogether. 

  10. Yes, you’re absolutely right, they are without doubt a by product of processing. So the MT happens very late in the processing, in fact it’s usually the last thing I do.  The final image is the result of only 1 iteration with MT with .20 amount and 0.75 selection. To my eye, it was the best compromise as any higher settings increased the artefacts a lot. 

  11. Thanks xplode but I’m afraid you’re way off. Noise reduction was very minimal through MLT - the amount of data helps here. The filaments you refer too are a by product of morphological transformation to reduce the stars and this was caused by my inability to produce a star mask of any value. I’ve been reprocessing this all day and I’m not sure whether my initial DBE is causing issues right at the start or not but there is something in my steps that isn’t working. Have a look at Sara’s version on her web site, her colours are far better. 

  12. Ran into all sorts of issues with this and couldn't quite get the colours right. Star masks were nigh on impossible so I skipped deconvolution altogether. There is a lot of data in this (2 panel mosaic, 10 hrs in each HA, O3 and S2 for each panel) but I feel that the HA wasn't as sharp as it could have been. It may still have something but I'd be interested in other's opinions please? Thanks for looking,

    Steve

     

    V6resized22.png

    • Like 9
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