Author Topic: Background too light  (Read 1681 times)

Offline Ken82

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Background too light
« on: 2018 December 08 09:30:35 »
Hi all,
Im having a slight issue im hoping some of you experienced guys can help with. Basically i cannot get the background to darken even after using DBE and ABE. It appears to actually lighten the background which means i cannot stretch the histogram very much. Ive also tried background neutralization which also lightens the background.

https://drive.google.com/file/d/1OYaKx0WBvpiF4wUbHkPpAtkaIFfqx8gW/view?usp=sharing

Thanks Ken 

Offline Niall Saunders

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Re: Background too light
« Reply #1 on: 2018 December 08 10:34:25 »
Hi Ken,

When I first dowloaded and opened your image, and applied an automatic ScreenTransferFunction, what I got qas the first image - with a heavy red tint.

So, I 'unlinked' the STF sliders and tried again - which gave me the second imgae - at which point I could have tweaked the re-linked sliders for best contrast - but I would normally do that after DBE, BN, and BCC (all preceded by a Crop)

Just for your information, I have attached the sliders of the two STF setups (linked and unlinked).

Hope this helps.

Cheers,
Niall Saunders
Clinterty Observatories
Aberdeen, UK

Altair Astro GSO 10" f/8 Ritchey Chrétien CF OTA on EQ8 mount with homebrew 3D Balance and Pier
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Offline pfile

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Re: Background too light
« Reply #2 on: 2018 December 08 10:42:37 »
yes i don't see a problem here - after DBE and STF->HT and another small histogram tweak: