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Helicon brackets losing highlight recovery

Posted: 07.10.2024 01:19
by horshack
For product-photography I use a white backdrop where I occasionally blow-out the background slightly in order to achieve the desired exposure on my subject. Even though the white backdrop is blown I'm able to bring it down in post and have the color remain white since only one or two channels is blown.

However for focus stacks I assemble in Helicon the highlight recovery no longer works - ACR/Lightroom renders the recovered highlights as pink. This is on an Olympus OM-1.

Here is an animated PNG I've created showing the highlight recovery of an individual exposure vs a 5-shot stack created by Helicon:

Image

Re: Helicon brackets losing highlight recovery

Posted: 07.10.2024 09:56
by Catherine
Hello,

I'm not seeing any visual issues on this photo. Are you exporting the result to DNG?

Re: Helicon brackets losing highlight recovery

Posted: 07.10.2024 15:59
by horshack
Catherine wrote: 07.10.2024 09:56 Hello,

I'm not seeing any visual issues on this photo. Are you exporting the result to DNG?
Look at the pink color cast on either horizontal side of the subject in the second frame of the animation, as compared to the absence of cast in the first frame. This is a DNG exported from Helicon.

Re: Helicon brackets losing highlight recovery

Posted: 07.10.2024 23:47
by Catherine
The color of the white background? Yes, now I see it. We'll need the source images to reproduce the issue, can you provide them?

Re: Helicon brackets losing highlight recovery

Posted: 08.10.2024 20:21
by horshack
Catherine wrote: 07.10.2024 23:47 The color of the white background? Yes, now I see it. We'll need the source images to reproduce the issue, can you provide them?
Thanks. Sent you a PM with a download link.

Re: Helicon brackets losing highlight recovery

Posted: 09.10.2024 12:06
by Catherine
Stack with the "Adjust brightness" option turned off in the Helicon Focus preferences - Autoadjustments. That seems to produce a good result.
We'll try to find out why this happens, probably some asymmetric clipping issue (one color channel gets clipped).

Re: Helicon brackets losing highlight recovery

Posted: 19.10.2024 18:03
by shutterbug
Could it be a difference in colour profile?

By default Adobe uses "Adobe DNG" for DNG files and "Adobe Color" for RAW files which can cause differences. There's also often times a shift in White Balance taking place (especially when one didn't pay attention and use a fixed white balance setting for the RAW files) which could result in a difference in white balance etc.

Re: Helicon brackets losing highlight recovery

Posted: 19.10.2024 22:05
by Catherine
In this case it's not that.