Support for multi-frame raw images with different exposure for wide dynamic range

[LigH-de]

There are cameras which are able to save raw image files containing more than one frame, for different purposes. One group are Fujifilm FinePix EXR cameras with Super CCD sensors containing two subsets of Bayer matrix pixel arrays, shifted by half a pixel diagonally.

I have a FinePix S200EXR. Dual frame raw images are saved for HR mode ("high resolution" with half a pixel diagonal shift, according to the EXR sensor layout) and for the DR mode ("dynamic range") with different exposure for each of both pixel arrays ... but only if there was sufficient contrast to require two frames to cover the dynamic range.

I will offer a few archives containing RAF files with two frames for testing support of the DR mode – which seems to have a chance to be supported in a determined way (in contrast, supporting the HR mode would require speculations about interpolation).

MediaFire: EXR-DR

There are even raw images with 3 frames, created by some Pentax cameras, according to https://github.com/jcelaya/hdrmerge/issues/137

[pi99y]

I just revisited my old Fujifilm X10 again and would love A WAY of ~blending sub-images within RT.

Perhaps user could select two sub-images and then, with a slider, choose how to mix shadows/highlights of the two?.

Subimage: [ 1 ]        Subimage: [ 2 ]
|============================O=======|
Shadows                     Highlights

Or perhaps such blending could be a "local adjustment" so that the feature would have other uses (blending different images) not just merging sub-images.

Currently I export two exposures and then mix them in Gimp. It works fine, but it's way too time consuming if you want to do more than a few photos....

Please consider it, and thank you for all the work on RT!

[Floessie]

@pi99y I can only give you the same advice that I gave in #5450: Have you tried HDRMerge? It works very well with the EXR DR files from my F600EXR...

[LigH-de]

It is actually better to mix them while respecting the different Exposure Values, to expand the dynamic range, and use HDR tone mapping. Possible tools are e.g. Luminance HDR, HDRMerge, 💰 Dynamic Photo HDR or 💰 easyHDR.

[pi99y]

Hi, @Floessie & @LigH-de, thank you for responding and your suggestions. Yeah, I tried two of those tools (Luminance HDR, HDRMerge), but the first results had massive ~artifacts - due to my laziness probably (not learning the tools and just blindly guessing what to do). I then just switched to Gimp where I knew how to approach it. It's not that it would currently be impossible to get a full DR image, it's just that its too time consuming to edit "the whole vacation set" this way, and if I were able to do it all within RT it would be great, especially with processing profiles getting me half-way there, like with other raw files.

I understand this isn't easy to implement or that maybe you don't think this belongs in RT, I wanted to indicate that there are more users who would appreciate such a feature and that it could be a multi-use feature (as described above, with multiple files/images perhaps), not just for specific sensors. :crossed_fingers:

[LigH-de]

IMHO, easyHDR is worth a try, if you can afford it; I helped the developer supporting DR RAFs of my S200EXR.

[pi99y]

Hey thanks for the suggestion! I tried the demo briefly, just now. It looks it can do wonders... however it is an elaborate, separate workflow, and like mentioned earlier I can't imagine doing this for a lot of photos...

I'm hoping that a simpler method, could one day nearly automate this and thus make it a part of my existing RT workflow...

Something along the lines of... "place highlights of less exposed sub-image over highlights of normally exposed sub-image, with basic user control of highlights selection". One could then make this a part of a processing profile and just adjust the highlights selection slider a bit... One can hope, right? :)

Maybe someone will find it worth of implementing :crossed_fingers:

Thanks again!