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Mask for HDR module

Posted: Fri Apr 23, 2021 5:08 pm
by Carles
I'd like to have Masks in the HDR module.

For instance in this M82 M81 dataset, when I do Tame highlights, it works really well on M81
but it makes an "oval" artifact on M82.
HDR.jpg
HDR.jpg (226.19 KiB) Viewed 3933 times
so would be nice to be able to make HDR affect only certain area with one preset.
in this case when I use Reveal core, M82 is not bad but M81 I don't like it at all..
HDR RevCore.jpg
HDR RevCore.jpg (244.25 KiB) Viewed 3933 times

Also when I use SuperStructure with a mask, and Isolate preset for example, it seems it affects
the masked out area too.

Regards

Carles.

Re: Mask for HDR module

Posted: Sat Apr 24, 2021 1:30 pm
by admin
Hi Carles,

You may find this thread of interest;
viewtopic.php?f=10&t=2145&p=9554

In a nutshell you can selectively use the output of any module if you really wish, however masks are used in many different ways besides selective processing. Selective processing is ideally carried out as little as possible.

Re: Mask for HDR module

Posted: Sun Apr 25, 2021 2:37 pm
by Carles
Hi Ivo,

I will check that.
Even though, what is the reason for that to happen? Is the algorithm compensating the light
in a circular or oval manner?

thanks for the suggestion.

Carles.

Re: Mask for HDR module

Posted: Mon Apr 26, 2021 2:48 am
by admin
Hmmm... I'm not sure I'm seeing the oval artifact... (I tried replicating it with another M81/M82 dataset).
That said, the smaller you make the Detail Size Range, the "harsher" the effect will be. However you should never see sharp transitions between treated and untreated areas (that would be a bug).

Also, if you use FilmDev instead of AutoDev (as stated in the AutoDev docs), then you and the algorithms will have to work a lot harder to optimise the dynamic range allocation compared to when you would start off with a perfectly balanced/neutral allocation like AutoDev provides.

Re: Mask for HDR module

Posted: Mon Apr 26, 2021 8:42 pm
by Carles
thank you for your answer, Ivo.

Well...I see it pretty clearly surrounding the M82 core...
Or you mean you you didn't see it when processing other M81/82 file ?

And I tried both AutoDev and FilmDev, and the resulting "oval" appears usually. (GPU version)
I tried it again now, and perhaps did the ROI different in AutoDev...but the "oval" shape didn't appear in M82.
Actually, "Tame" didn't have any effect at all at M82... but it did on M81.

I don't know why it did happen, but is not the first time. Will keep checking and if I find the conditions on that
to happen will let you know ^^

Regards

Carles.