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kosborn
13-05-2018, 12:05 AM
An attempt at the running chicken... I know I should have got more data but it's been constantly cloudy so I put together what little bit of data I have. This is narrowband but after reading somebody's "Swedish flag" comments about the Hubble palette I thought I'd try something different. This is red (0.5 Ha + 0.5 SII), green (0.15 Ha + 0.85 OIII) and blue (0.15 Ha + 0.85 OIII) processed in PixInsight. Only 4x 5min exposures for each filter. I've read lots of comments on different forums about internal reflections with the ASI1600MM and that's certainly happening around lambda centauri in this image!
Kevin
A good start Kevin, lots of nice colour and detail.
Someone else should help with how to fix the artifacts.
Atmos
13-05-2018, 09:25 AM
It is quite a nice colour, well captured and processed.
Lambda Cent is a pretty bright star. The internal reflections you're seeing there look like they're from the filters more so than the ASI1600. Which filters are you using?
If you are wondering the reflections from the ASI1600 look like check this one out (https://www.astrobin.com/full/321338/0/) and look at the star in the lower right. That colourful square pattern :P
kosborn
13-05-2018, 11:26 AM
Thanks Peter.
Thanks Colin. I thought that the internal reflections people were discussing were the reflections between the sensor cover and the filters. I didn't realise there were also issues with reflections actually inside the camera. I'm using the ZWO 7nm filters and I was very careful to put them in the filter wheel the right way around. I found a web page with instructions on how to correct the artefact (http://trappedphotons.com/blog/?p=616) (http://trappedphotons.com/blog/?p=616) but it's pretty involved and I haven't tried yet. It would probably be easier to remove the square artefact with this method.
Kevin
xelasnave
14-05-2018, 06:17 PM
I nearly missed this.
Well done again.
I missed having a go at this one...
Dont worry about the reflections adds to the character as the rebellious stars refuse capture...
Nice one.
Alex
multiweb
14-05-2018, 07:07 PM
Cool colours and nice details. :thumbsup:
kosborn
14-05-2018, 08:13 PM
Thanks Marc
Thanks Alex. There's plenty of chicken left if you are still hungry. I had seconds last night and I'm having a third helping right now. ;)
Cheers, Kevin
rcheshire
14-05-2018, 08:40 PM
Nice work Kevin.
kosborn
17-05-2018, 10:04 AM
This is my final version after more data and more processing. Red, blue, a bit of yellow - I think I'll call this the superman palette... There was better data after a meridian flip so the final version is inverted from the original.
Kevin
A clucking good image, I'd be happy to get something so good!
RickS
17-05-2018, 02:04 PM
I like the Superman version :)
kosborn
17-05-2018, 06:51 PM
Thanks Sil.
Thanks Rick. The image is much softer than I'd like. One thing I didn't do (and will still try) is deconvolution on each of the light masters before combining them although I did do a (nonlinear) multiscale linear transform for sharpening as one of the final steps. I've read different advice about pixelmath combination then stretch vs stretch then combination. As a PI maestro do you have any advice on combining and sharpening?
Kevin
RickS
17-05-2018, 07:10 PM
Hi Kevin,
I normally create a synthetic luminance from the NB masters by combining them with ImageIntegration, typically noise-weighted and with no rejection (for bi-colour add the files twice so you don't get the less than three files error.) You can sharpen this with decon while linear. After stretching and before combining with the colour data I apply a clipped lum mask and apply MLT sharpening as well. You need to have a light touch and only sharpen as much as the data allows. Otherwise Mike Sidonio will call you out for decon worms :lol:
Cheers,
Rick.
Retrograde
17-05-2018, 07:30 PM
Loving the repro. A very fine image.
kosborn
19-05-2018, 02:16 PM
Thanks Rick,
I took your advice and have a much sharper image now. Funny though that I couldn't find blue in the same places with this version. Can't see any worms but happy to take advice. :)
Cheers, Kevin
xelasnave
19-05-2018, 02:35 PM
Kevin please try the xelasnave palette.
I want a processing program that presents my images in black and white with little numbers that show which colour to fill in with.☺ I recall I was not bad at colourung in if given the correct coloured pencil.
Alex
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