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

[johming]

do you know guys if is there some software that cha transform the dual iso .raw video files directly in a cinema dng ora in a prores file?

[swinxx]

Mlvmystic 0.5

[smier]

I've just tried a timelapse with AETTR and Dual ISO, I have a question about the workflow.

After importing all my files, do I want to process all the dual ISO into DNGs before editing the image or do I edit the cr2 file, then process the dual ISO into DNGs? I'm assuming the first option but just wanted to make sure.

Any other workflowthat I may need to consider for AETTR Dual ISO timelapse vs AETTR timelapse? I'm using the LR Cr2DNG plugin from another thread and adobe bridge deflicker script if the ML deflicker XMP files aren't enough.

[barepixels]

Hi, I'm new to this forum, so please forgive me if this is not posted in the correct thread.

I just installed ML on my 7D, mainly to take advantage of the dual ISO feature.  Under relatively normal lighting conditions, it works fantastic; however last night, I was taking longer exposures on a tripod and noticed that all of my pictures taken with dual ISO have hundreds of random black marks scattered throughout the frame.  I thought this was related to the sensor overheating, so I ran some benchmarks with and without dual ISO and with and without Long Exposure Noise Reduction.  I figured the noise reduction would do the trick, but I was surprised to see that every photo taken in Dual ISO, regardless of whether or not noise reduction was activated, had these spots, all in the same places.  Exposures without Dual ISO turned on were fine at both the low and the high ISO, with and without LENR.

Is dual ISO just overwhelming my sensor?  Has anybody else had this issue?

Very interested to hear your thoughts.  Thanks.

long exposure - black dots

prob hot pixels fix in camera.

[convexferret]

I've been following ML for over a year now and find it invaluable, dual ISO included. I have a little workflow tweak suggestion that would help me a great deal, assuming that I've not missed the idea already being mentioned or that the hooks etc don't exist.

Where I live we get 320 days of sun a year, precisely the sort of weather where a large dynamic range is helpful, so much so that I often leave dual-iso on all day. However, I then forget to switch it off as the evening arrives and my ISO hits 1600+, until I see the results on the screen.  Control via auto-ettr isn't really an option as I find it a bit slow at times. What I'd like to see is a switch that when you have dual-iso enabled, will auto-disable it above certain ISOs. For me that would be around 1600 and over, the point at which it starts to cause problems (green shadows etc).

Is that even feasible?

[RTLdan]

Hi all!
 I've read through this entire thread once before...but I'm going to risk asking a possibly obvious question instead of
rereading all 88 pages.

I took a bunch of photos tonight. About half were dual iso, the other half were taken normally. I forgot to make a new folder when I was taking the dual iso ones, and I switched dual iso on and off quite a bit to do comparisons. Is there a way to easily identify which are which? I just pulled up the card in Canon DPP and I don't see the interlacing!?

Thanks again, and sorry if this question was addressed (multiple times) before.
-Daniel

[lureb74]

Hey guys, hope i aint being a nuisance, but any update on the "bright dark detection error, iso blending didnt work" bug?
im really desperate for a fix

or would it be possible if the developers let us know if a fix is to be expected anytime soon, because if not we can move on from waiting and continue with an alternate method



update and notes and tutorial for the un educated people on the following problems:
"bright dark detection error, iso blending didnt work"
flickering when filmed with dual iso

using the older version:
2014.04.08\cr2hdr-20bit.exe, doesnt give the "bright dark detection error, iso blending didnt work" error
whilst
2014.05.06\cr2hdr-20bit.exe, DOES
so apply same levels in post yourself, as cr2hdr same levels parameter uses exiftool to apply same levels anyway
processes the 0 and 1 files, and to apply same levels i used, ExifToolGUI, run the program, navigate to first file of the sequence, on the right find BlackLevel and WhiteLevel, note down the values, select all the files (i found that if i select around 2000 files it doesnt process the command so theres a file ammount limitation, 1430 worked, so maybe 2k is the limit?) at top right of the gui program, click on exiftool direct, copy and paste:

-Exif:BlackLevel=2046

NOTE, the 2046 is the variable, enter the BlackLevel you noted down from first file, click on ok, itll process the files, and create a backup of the original files, if you dont want them backed up, go to options at top left > dont backup files when writing.

now repeat the procedure for the whitelevel:

-Exif:WhiteLevel=2046

again the 2046 is the variable, click on ok, once both the whitelevel and black level have been changed to match the first file of the sequence, there should be no flickering what so ever, i dont believe ACR caused the flickering in the first place, as when i applied ACR adjustments, even to extreme cases, like -100 highlights, +100 shadows, etc, no flickering was caused what so ever

Hi, I agree this way is very useful for dual-iso video flickering prevenction... but I just figure out what is another cause of flickering, sometimes still visible even after the "ExiftoolGUI-FIX":
dual-iso videos have the dark-light stripes that exchange position every other frame, I mean you have one frame as (example) line 1-2, 5-6, 9-10, etc. at (example) 100 ISO and 3-4, 7-8, 11-12, etc. at 800 ISO, then the next frame is 2-3, 6-7, 10-11, etc. at 100 ISO and 0-1, 4-5, 8-9, etc. frames at 800 ISO. This cause a little flicker, sometimes visible in hi contrasty and/or hi-iso difference situation.

Lorenzo

[kyrobb]

Does anybody have accurate info on which camera's are currently able to run Dual ISO in raw video mode? I keep reading conflicting things.

[RTLdan]

Hi all!
 I've read through this entire thread once before...but I'm going to risk asking a possibly obvious question instead of
rereading all 88 pages.

I took a bunch of photos tonight. About half were dual iso, the other half were taken normally. I forgot to make a new folder when I was taking the dual iso ones, and I switched dual iso on and off quite a bit to do comparisons. Is there a way to easily identify which are which? I just pulled up the card in Canon DPP and I don't see the interlacing!?

Thanks again, and sorry if this question was addressed (multiple times) before.
-Daniel

Ok, ok, so maybe I was a little lazy last night after shooting and I didn't search hard enough. Did another google search today and came up with a reference to a dual iso tag that should be in the exif data. That sounds promising. Only problem is, using a photo that I'm almost positive I took as dual iso, I cannot see this tag using either Canon DPP or the command line exiftool.
Any ideas on where to look for the dual iso exif tag, and/or, a nice gui based windows exif viewer?

Thanks!
-Daniel

[barepixels]

when you preview Dual ISO file, you should be able to see scan lines.  if not zoom in in Light Room

[simpsus]

Hallo,

I am a Fedora-Linux user and I tried to get cr2hdr to work.
First I tried to build it from the source using the method outlined here for Ubuntu:
https://bitbucket.org/hudson/magic-lantern/commits/50345b4d561151e4707c04e2b874e1f909bef6d9
But I gave up on the part of using dpkg to prepare the gcc compiler.

Luckily I came across the bitbucket archive of rufustfirefly
https://bitbucket.org/rufustfirefly/magic-lantern/downloads
where I can download a statically linked binary. Cool. 32 bit, I use 64, but it still works.

However when I call it with one of my files, it gives me:

Code: [Select]

[bastian@simpsus 20140712]$ ~/temp/cr2hdr-static.linux.x86.2014-06-19-f9a29c7c0685 IMG_0123.CR2
cr2hdr: a post processing tool for Dual ISO images

Last update: 30a5132 on 2014-05-07 10:34:25 UTC by a1ex:
cr2hdr: print a message when overwriting the output file

Active options:
--amaze-edge    : use a temporary demosaic step (AMaZE) followed by edge-directed interpolation (default)
--cs2x2         : apply 2x2 chroma smoothing in noisy and aliased areas (default)

Input file      : IMG_0123.CR2
Camera          : Canon EOS M
Full size       : 0 x 0
Active area     : 0 x 0
Error: pgm width

which I cannot make any use of. Has somebody a hint for me to either
use cr2hdr on linux/fedora or
how to get rid of this error?

Thanks,
Bastian

[a1ex]

Sounds similar to this: http://www.magiclantern.fm/forum/index.php?topic=7693.msg69865#msg69865

[Ikare]

Hello everyone,

Since yesterday, I test DualISO mode on my DSLR.

In the menu, it is now possible to choose values ​​as: 100, 200, 400, 800, 1600, ...

However, multiples of 160 ISO get better result to retrieve the dark tones, why not add: 160, 320, 640, 1250 ...?

To get there, I tested the functionality upside down, and I set the camera to ISO 2500, then DualISO on -5EV
Recovery of Shadows was better (less chromatic noise) than with the device in 100iso and DualISO 1600.
With 1250iso and DualISO -4EV and the results were also better.


What do you think?


Thanks

[Audionut]

http://www.magiclantern.fm/forum/index.php?topic=10111.0

[Ikare]

http://www.magiclantern.fm/forum/index.php?topic=10111.0

thanks, I try to understand the information on the Topic, even if it is difficult to translate the information in my native language.
But I can not understand why I got a better result with that in 1250 and 2500 to 1600 ...

[Audionut]

Care to upload the CR2?  100/1600 and 100/2500.

[a1ex]

2500/100 is more like 2500/80, since the intermediate gains are the ones of the base ISO. Dual ISO only operates on the full-stop amplifiers.

Shadow noise should be equal in 1250 and 1600. In 2500 is lower, because it's based on 3200.

[simpsus]

Sounds similar to this: http://www.magiclantern.fm/forum/index.php?topic=7693.msg69865#msg69865

Thanks, the language setting solved it

[a1ex]

That should be actually included in the source code, just making it cross-platform is a bit of a hassle.

[Ikare]

Care to upload the CR2?  100/1600 and 100/2500.

2500/100 is more like 2500/80, since the intermediate gains are the ones of the base ISO. Dual ISO only operates on the full-stop amplifiers.

Shadow noise should be equal in 1250 and 1600. In 2500 is lower, because it's based on 3200.

Ok, I had not kept my tests yesterday, but I had increased only shadows on Camera Raw to see the difference (it was a mistake, see below)

Today I made ​​a new test with these values​​: 800/100, 640/100 (more like 640/80 as stated a1ex) and 400/100

Here are the results (they are 100% crop of a dark area):

800iso :

high res : http://i.imgur.com/hHrpgUh.jpg



640iso :

high res : http://i.imgur.com/RDJlhAW.jpg

400iso :

high res : http://i.imgur.com/sHbzzbs.jpg

We can see that the three images do not have equivalent exposure if exposure increases equally, despite compliance photographic units (I had not seen the difference yesterday).


(a1ex & Audionut, merci pour vos réponses, et surtout un grand merci pour votre travail)

[Audionut]

2 points to note:

The shadow slider in ACR is not linear.  It will produce different results.  Do not use it for brightness matching.
All exposure adjustments should be equal.  All exposures are brightness matched by cr2hdr, the only difference being the level of noise in the shadows.

The exposures are matched from the lower ISO, ISO 100 in this case.  The higher ISOs are only used to clean the shadows, they do not effect brightness rendering.

[budafilms]

2500/100 is more like 2500/80, since the intermediate gains are the ones of the base ISO. Dual ISO only operates on the full-stop amplifiers.

Shadow noise should be equal in 1250 and 1600. In 2500 is lower, because it's based on 3200.

A1ex this is only for DUAL ISO? If not where I can get the table/values to know which is the maximum ISO with the same shadow noise?

[a1ex]

I assume you are interested in RAW movie mode, where you only have full-stop ISOs, so check this graph: http://www.magiclantern.fm/forum/index.php?topic=10111.msg118553#msg118553

[budafilms]

I assume you are interested in RAW movie mode, where you only have full-stop ISOs, so check this graph: http://www.magiclantern.fm/forum/index.php?topic=10111.msg118553#msg118553

Wow!
dr_1080 =   [ 11.10  11.05  11.02  10.93  10.73  10.39  9.88  8.88  ];

I will go up with ISO!

[Pierre Jasmin]

I am trying to see if this is expected

I rented a Mark III to test dual ISO video (with proper card...).

With normal video I get frame A a certain exposure, and frame B another one - and A,B,A,B alternating
With RAW I don't understand what I got

I have a frame with a certain exposure then the other frame has a 2 scanline pattern, 2 scanlines same exposure (light) followed by 2 scanlines (dark) and so on.  Here's a JPEG of what the bad frame(s) look like.

http://www.revisioneffects.com/bugreports/ML/testML.jpg

I would expect either alternating exposure on a frame or scanline basis but not every 2 frames every 2 scanlines
I thought it might be the converter from .RAW to .dng but I tried different ones with same results

This was for the most part 1080P 30 FPS, I did follow the instructions

So the first question is with RAW video dual ISO what should I expect?
Is there sample .RAW files somewhere I can go through same conversion workflow to see it's not me introducing this problem?

Pierre