Dual ISO - massive dynamic range improvement (dual_iso.mo)

Started by a1ex, July 16, 2013, 06:33:50 PM

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"So? I compare reds with reds and blues with blues, not reds with blues."

Just thinking, you're comparing reds with interpolated reds(interpolated from only red data from the other brightness image).
Actually you're comparing the red data with itself.
Edit: Not true, red and blue are both in the dark and bright image (See A1ex reply below)


Quote from: Levas on August 29, 2014, 10:47:15 AM
But dual iso means alternating lines, so the bright image contains the blue pixels and the dark image contains the red pixels.

Nope ;)


Looking at the white paper now, and see that it alternates every 2 lines  :-[, that explains a lot.

How does it work for dual iso video, with the line skipping ?
Are both red and blue as wel in the dark image and bright image ?

EDIT: Looking at a video frame now, seeing both dark and bright lines are 2 pixels in height, so both red and blue are in the brigt and dark area's.



@Kitchehof. Awesome!
@Alex. Biggest thanks for this fix. Will try right now.

No more border issues converting dual iso moviefiles using 3x zoom mode thanks to Alex fix. in 20bit cr2hdr. Sweet!


"fixed another border condition"

Testing this new CR2HDR build and I think "fixed another border condition" is not the only thing that has changed/fixed  ;D


@Levas exactly :) this is the latest commit!

You can see all commits here for cr2hdr-20bit!

Many thanks a1ex!


Thanks A1ex! 
CR2HDR-20bit output has improved a lot for dual iso lineskipping video  :D

I'm using this new build in your Lightroom plugin, opened the plugin in finder and replaced the CR2HDR20bit file with this new one, works !


Well, the ISO matching method from previous binary passed most of my tests, but not all. I went back to my previous algorithm, and replaced the highlight median with a brute force search, somewhat similar to RANSAC. The nice property of this algorithm is that it handles a huge number of outliers, as long as the relevant data points are clustered together, and the outliers are scattered all over the place.

Here's something that seems worth reading (I didn't read it yet, only looked at pictures): RANSAC4Dummies.pdf

Anyway, here's an update that passed all my tests: cr2hdr-20bit.exe

And here are the tests: https://www.dropbox.com/sh/xfkizhu4lpoiuc8/AAC5GkEpZVacRUXcfrv1ikwVa?dl=0

(some very difficult images were 000166, 00017x, _46A0416, _46A3766, _UAL1304, IMG_2524; the previous binary failed at _UAL1304)


$ ./cr2hdr
cr2hdr: a post processing tool for Dual ISO images

Last update: 0eabcb0 on 2014-08-29 12:42:54 UTC by a1ex:
cr2hdr exposure matching: when all else fails, brute force prevails...

Download cr2hdr-20bit for Mac only with last commit 0eabcb0 ;)

Download here


"When all else fails"   Ha ha ha  :D

I think I start off with this build from now on  8)

Or is there a reason not to starts off with this "when all else fails" build and is it (picture quality wise) better to first try the previous build(s)  ???


Thanks for improving my life with fun stuff called Magic Lantern!!  :)

I have been testing the latest 2014-08-07 00:01:30 +0200 5D.123 build with dual iso.
I can not prosess any .dng files on PC.

Win 7 pro 64bit
5D Mark III

-I first converted the MLV files with Raw2Cdng, Mystic and Mirawviewer in Win 7 PC.
-I then tried converting all the different files with an "old" cr2hdr.exe I found on my pc, I downloaded it August 9th 2013.
-I then downloaded  cr2hdr from the link provided in this thread/forum on page 1, tried both the regular one and the 20bit.exe

*20bit.exe converts my dng`s into something cracy.
It produces really messed up files, where the dual iso lines are still present and the colors are loco and pink-ish.

The regular c2hdr converts only 1 dng and then crashes, everytime.
The finished file is just as crazy as the ones that 20bit.exe makes.

Then tried with barracudaGUI, still crazy files coming out..

after all this I tried with another MLV that was recorded with build, 5D.113 2014-07-08 01:11:45 +0200
Made dng`s with Mirawviewer and then dropped them all onto the 20bit.exe.....
Peeerfect with both old and new cr2hdr.exe`s.

That leaves me with not being able to convert dual iso made with the build I am on today, 5D.123 AND WINDOWS
I tried the same dng`s that with a Mac, and that worked without trouble.
Am I missing something?



from mlv.dump
I am thankful that Jesus and MagicLantern exist, because they both change lives!



Is it possible to check the exposure in camera when shooting dual iso? Does previewing photos still work the same or is it weird looking? Tried searching, but couldn't find anything.


Quote from: Audionut on September 05, 2014, 11:46:49 AM
Use raw based exposure guides.

Does this mean that I have to use liveview to see exposure? I'm interested in dual iso for stills atm.


You can check you're exposure in live view and close it, and then take your still ?
Or stay in live view and make you're still...


Or don't enter LV at all and simply take a photo. The overlays show up in QR too


I shoot quite bit of photos using dualiso and am developing them on my mac. The lightroom script is very nice, but on the mac I see a problem using the commandline tools for more interactivity (mainly me not realy understanding how to work with them or installing). That is why I thought using one of the already existing (commercial) programs might ease the workflow for me. So, I asked one company if they wouldn't be interested in supporting dualiso dng's. They told me that they don't know exactly, but that the dng's would lack two different tags to be opened correctly to start with.

These tags are:
CFAPlaneColor tag 50710
CFALayout tag 50711

I absolutely don't know what to do with this, but thought it might be of interest for everybody to pass on this information. I hope I didn't do anything wrong.



Ok, I need some help here. Maybe a dumb question but... I made all the steps for processing my dual iso photo and in the end I cannot open the final DNG file. Which version of Photoshop and ACR do I need? I have Photoshop CS3 and ACR 4.6.
Thank you all.


QuoteOk, I need some help here. Maybe a dumb question but... I made all the steps for processing my dual iso photo and in the end I cannot open the final DNG file. Which version of Photoshop and ACR do I need? I have Photoshop CS3 and ACR 4.6.
Thank you all.

Try running the Dual ISO DNG through Adobe DNG Converter (FREE) and set the ACR to match what you have. I don't think you'll find anyone here actively using that old of a version of Photoshop. Beside all of the advances in photo processing in the last 5+ years.... it may be time to think about an upgrade. At least try Lightroom 5.6 it's free for 30 days...
5D Mark III -- 7D   SOLD -- EOS M 22mm 18-55mm STM -- Fuji X-T1 18-55 F2.8-F4 & 35 F1.4
Canon Glass   100L F2.8 IS -- 70-200L F4 -- 135L F2 -- 85 F1.8 -- 17-40L --  40 F2.8 -- 35 F2 IS  Sigma Glass  120-300 F2.8 OS -- 50 F1.4 -- 85 F1.4  Tamron Glass   24-70 2.8 VC   600EX-RT X3


If you want a free raw converter I can recommend RawTherapee.


I'm using both Lightroom 5 and Raw Therapee.
Lightroom is a lot easier to use, but the more I get used to Raw Therapee, I think Raw Therapee gives me better results, especially with dual iso files (better debayering better false color elimination etc.).


Quote from: Stedda on September 14, 2014, 04:31:07 PM
At least try Lightroom 5.6 it's free for 30 days...

Or cost $9.99/month with Lightroom and Photoshop. Always up to date!


Lets say we do a full day of shooting a mix of regular and dual iso movie clips/shots. Anyway we can differentiate between the two when post processing?


Custom file prefix and/or metadata keyword "Dual-ISO".