dual iso+hdr raw video?

[mlrocks]

I just did a quick experiment, for hdr, I chose 100/12800; then in dual iso, I chose +6ev to get only 1 stop improved dr. if I only use dual iso, I can get 3.5 stops more with +6ev.
I am thinking maybe in hdr, choose 100/1600, tehn in dual iso, I will choose +3ev.
I do mostly landscape, so movement is not a concern, but dr is. so I am thinking to get maximal dr to combine hdr and dual iso. maybe if it is successful, 5d3 can really compete alexa?
anybody tried dual iso plus hdr for raw video shooting? your input is welcome.

[Danne]

Why don,t you try yourself? There must be a conflict when going back and forth in hdr iso and running dual iso settings at the same time. My suggestion is stick with hdr if not using dual iso in 3x zoom mode.  I say stick to hdr since you mention slow movement.
Feel free to check out MLP if on mac for post processing.

[Levas]

Dual iso and HDR make both use of the same trick, recording with 2 iso settings.
Dual iso uses 2 iso settings in 1 frame and dual iso HDR switches iso settings between frames.
Since both use the trick of combining 2 iso settings, they don't add up if you combine them, result by using both will be about the same as using one of the two.

Think about it. For both you have to set 2 iso settings.
Let's say you choose iso 100-6400 for dual iso.
And for HDR iso 100 + 6ev(so resulting in iso 6400).
Enabling both will give you recordings in iso 100 and iso 6400.
Just as enabling one of the two will give you.

[Danne]

Well if you would do something like hdr 100/3200 and dual iso 400/1600 it would probably get you some extra midrange. Don,t think this would show in end result anyway.

[mlrocks]

just tried hdr 100 1600, my idea was to have two physical frames with low 100 and another 1600. then in each frame, use dual iso +3ev to expand in each physical frame. seems ml does not recognize two frames, it only recognize one frame, either 6400  or 100, not both simultaneously. then ml calculates dual iso based on this single physical frame.
imho, magic lantern can do the combination of the both to improve dr further so that 5d3 can match alexa or red dragon. but it is beyond me, hopeful alex can come with a solution. this is actually very useful for practical reasons.

[mlrocks]

if there is a module that link hdr and dual iso, this is actually affecting the end results. it is like hdr still photography, if you have only two frames in one bracket, each frame need to cover a lot and the overlayed region is not much. if you have 4 frames in one bracket, you have much better tonality and dr range. in addition, if you extract each raw frame several times and combine them, it is better than extract raw once. there are tests showing such comparison. so, 5d3 can beat alexa or dragon if this dr module works.

[mlrocks]

http://photo.stackexchange.com/questions/42190/multiple-exposures-vs-adjusting-exposure-of-single-raw
http://farbspiel-photo.com/original/creating-32-bit-hdrs

"Creating additional exposures with -4EV and -6EV actually pays off, contrary to the general assumption that you cannot get more details than present in the RAW files. "

[mlrocks]

so my suggestion to an integrated hdr raw video module will be like this:
1. hdr to get 2 physical frames
2. dual iso to get 2 half frames in each physical frame
3. in postprocessing, extract each raw frame three times
4. align and compress all in one single tiff frame
5. ffmpeg to codec prores4444

[Danne]

You can achieve extra infomatiion from a display referred(I think it,s called)(clipped) dng output. I imagine several ways one is lowering brightness in to bring back highlights, use luts and temper with dcraw highlight recovery settings. This would probably bring back some info from one dng file. Combine this with a copy of the same dng but pushed to clip brightness and bring out midtones.
Now with hdr this is already taken care of and you get a lot cleaner picture than pushing one image around less grain in shadows etc.
Now combining hdr with dual iso you could maybe recreate and compare what you are suggesting so we actually have some proof of higher picture quality.

[Levas]

you could test it in photo mode with current builds, that way you could test if there is some gain in picture quality.

Camera on a tripod
Enable dual iso
now take two pictures with different iso's (sort of faking HDR mode)
Postproces the 2 pictures and merge/blend them together.

Now for reference compare this picture, with two pictures with different iso's and merged blended together.
And one picture with dual iso.

Please post the pictures, because I'm actually curious now how much different it will look