New HDR algorithm in Darktable anytime soon?

[Thomas_Do (Thomas)]

@Zbyma72age

SNS-HDR Lite is freeware.

It’s not about “free” in the sense of no cost. A lot of people here use quite expensive camera gear, so money is not the first thing to consider for most.
Personally, I use linux and therefore need programs that run under that operating system. Sometimes, I also use proprietary software under linux . But in the case of darktable I am very happy with the active development and the concept of this FOS software.

[Daniel_Spenner]

Okay, thank you! That´s a sincere answer.

[Ramana]

Try to install the LUA scripts containing a great HUGIN script
and HDRmerge and Enfuse (image stack) for HDR processing

workflow in Darktable:

1. create HDR or LDR files first with HDRmerge or Image stack (LUA scripts)
2. make panorama with the Hugin LUA script.

[felixPQ (Yves Gauvreau)]

@Terry

@jorismak

And for me , I can’t remember the last time i thought about HDR bracketing. I guess this is why interest isn’t at an all time high.

I agree that modern sensors reduce the attraction of HDR and I very rarely use it. The new ISO invariant sensors from manufacturers like Fuji probably make it less attractive. One of the real improvements with late model cameras is the dynamic range. The Pentax samples I posted here are not because this shot really needed HDR, but the images really test out the software’s capabilities. And for once Adobe wins on this one with Lightroom. But then lightroom spits out a DNG which darktable loves working with. So that is my HDR workflow if needed.

Another HDR solution that I use is to process the bracketed RAW files in darktable, export 16 bit tiff files and stack as layers in GIMP and use masks for blending the exposures. This works really well for landscapes where you want to blend two exposures using a gradient mask. The only caveat is that GIMP lacks the alignment options found in Photoshop so you must have used a tripod to keep alignment.

Yes, it would be nice if all this could be done in darktable, but I am not going to ask the developers to devote 1000 hours to make this possible when good solutions already exist.

Creating an image via exposure stacking as other benefits than increasing DR, among which is noise reduction. This is especially true when the dynamic range is relatively large, the larger it is, the noisier are the shadows, assuming ETTR.

My 2 cent

[hatsnp (Nuno Paulino)]

Wouldn’t ETTR actually improve noise in the shadows since more information is captured? Given that the exposure is actually increased by letting more light in of course, and not through amplification.

[Terry (Terry Pinfold)]

@hatsnp

Wouldn’t ETTR actually improve noise in the shadows since more information is captured?

That would be true but exposure merging would still improve the noise more in the shadows than ETTR. Some scenes also go beyond any sensors dynamic range, but sensors have improved a lot in the last few years and this probably means developers are less interested in spending their time on HDR.

[rvietor]

Is there still that much to develop for HDR processing?
Has exposure fusing ever been part of darktable?
Iirc, such functionality was always through external programs (Hugin etc.).
And the final part (the tone mapping) is available in darktable.

As for noise: ETTR has two positive effects on shadow noise:

• more light captured, so better S/N (more noise, but much more signal: {\textrm{noise }} \propto \sqrt{\textrm{signal}}
• electronic noise is more or less constant, so will contribute proportionally less when there is more signal.

[kmilos]

Most sensors exhibit some improvement at higher ISO so bracketing might still make sense, though it is less dramatic in more modern ones:

https://www.photonstophotos.net/Charts/PDR_Shadow.htm

Note that some newer cameras like the GH6 already do dual gain in sensor.