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

[dickson]

I see now that this has been dealt with before - but I have the latest version of cr2hdr.

[apefos]

Today I finished my first tests with dual iso raw video with 600D T3i. I learned the workflow and I got good images.

Problem is: magenta dots everywhere.



Reading the forum I found many people have this issue, so I have a few questions:

Is there one or more Canon DLSR cameras which can do dual iso raw video without any dots? (i am interested only in video)

Is there a good working solution for the dots in the 600D T3i? (and/or for the other cameras)

Thanks!

[arturochu]

the cr2hdr-hot.exe work pretty good but if you drag more than 40 pics in one single click it will crash somewhere around picture 40; hope you can fix that so i can leave mi computer processing tons of photos (+1000) while i'm not home.

[engardeknave]

I've never got the confetti before. I wonder if my camera is just special and doesn't have any hot pixels.

the cr2hdr-hot.exe work pretty good but if you drag more than 40 pics in one single click it will crash somewhere around picture 40; hope you can fix that so i can leave mi computer processing tons of photos (+1000) while i'm not home.

http://www.magiclantern.fm/forum/index.php?topic=8520.0

[apefos]

Long time ago I found a plugin for dealing with hotpixels, it is free, no longer available, but I will allow a link for downloading it because maybe the developers can get inspired on it to find a solution for the issue:

http://www.apefos.com/dualiso/svpr.rar

I did a test in the cr2hdr-hot.exe and ir deduces the size of the hot pixels, but do not remove them completely, see the difference between the results from cr2hdr and cr2hdr-hot:

[a1ex]

the cr2hdr-hot.exe work pretty good but if you drag more than 40 pics in one single click it will crash somewhere around picture 40

Any hints about how to reproduce it?

I've tested it on 700 pics in a single batch with --fast, 100 pics with default settings, and 2 pictures in valgrind

[RenatoPhoto]

In Adobe bridge I can still see the alternating frames at different iso's.

Zoom into the picture and should see the dual iso LINES.  There are no alternating frames in dual iso, it sounds like you are working with hdr video with frames of alternate isos??

http://www.magiclantern.fm/forum/index.php?topic=2595.msg10605#msg10605

[dickson]

Oops, my bad, you're right. But dual iso is greyed out on my camera. I can manipulate the settings, but I'm not getting anything.

[apefos]

Here it is a RAW dual iso video recorded by the 600D T3i for download. I uploaded it because it gives me lots of magenta dots and can be used for reproduce the problem and improve the CR2HDR-HOT (drag and drop over the cr2hdr-hot to reproduce the dots in dng sequence)

http://www.apefos.com/dualiso/di600d.rar

[a1ex]

These DNGs were already processed, what should we do with them?

[apefos]

I believe I uploaded the DNG extracted from the RAW video using RAW2DNG.exe, not processed by the CR2HDR yet, so the idea is to use these DNGs to test the hot pixel remover in the CR2HDR-HOT.exe

Drag them over the CR2DNG-HOT.exe to see if the hot pixel removing works, you can use them to test the CR2HDR-HOT.exe until find a version which can corrects the hot pixels.

I know you can do this using your RAW and DNG files, I just uploaded these because was shoot with the 600D, and maybe the 600D hotpixels can be different from the other cameras like 5D3.

[apefos]

This is the link for download the original dual iso .RAW file from 600D which gives me magenta dots (hot pixels). With the .RAW file the tests can be better than using the DNGs I uploaded before.

https://www.dropbox.com/s/i4gs4qvzsbrbhwr/600d_raw_video.rar

[escho]

Servus

I can confirm, that remooving bad pixel from 600D raw-files is a problem. dcraw (ufraw) fails, darktable too. The only prog here on Linux is RawTherapee, that succeed, But this cannot be used for dual-iso pics, because the romooval has to be done before interpolation, I guess.

I looked at the code of cr2hdr and saw, that the badpix-remooval funktion only works on the dark lines of the pic. That´s not enough for 600D. So I changed the code for to work with the bright side of life too and compiled the module new,

With this test-change all badpix are remooved! Only on the border of the image some new ones are created, what is no problem for cutting out in postprocessing.

In my eyes, this function should be extended, to work with the whole image. And it would be fine to append this function to raw2dng and mlv_dump.

Edgar

[a1ex]

Can you upload a CR2 or interlaced DNG where this is visible? I didn't notice it in the ones from apefos (these shots have cold pixels in bright areas, but didn't see any hot pixels).

[escho]

Alex, did you have a look at the raw-video, apefos did upload last? cr2hdr tells me:

Code Select Expand

Looking for hot/cold pixels...
Hot pixels      : 116
Cold pixels     : 107

I for myself have to search for a file with hotpix. I only have cold-ones at the moment available.

Edgar

[a1ex]

Got it, that means the cold pixels can be anywhere. Since I didn't see any hot pixels on the bright lines, that check is for speedup and to avoid false positives.

I'll fix it when I'll get back.

[escho]

Great 

Edgar

[CaronteGF]

I having a problem trying to do my first Dual-Iso.
I configure the camera in RAW mode, load the module on ML, reboot and then enable Dual-ISO. But when i load the file with cr2hdr, i get "Doesn´t Look like Interlaced ISO" error.

I try to restore defaults of ML and then do it all again, but i get the same error.

Any idea?. Im using the last stable ML version (22Nov) on a 7D. I asume im making some wrong becouse is not a common error.

Tks you.

[Marsu42]

I configure the camera in RAW mode, load the module on ML, reboot and then enable Dual-ISO. But when i load the file with cr2hdr, i get "Doesn´t Look like Interlaced ISO" error.

Check if dual_iso was really enabled and working or cr2hdr is the problem. The effect of dual_iso isn't hard to see, if you zoom to 100% either in camera or on the PC (for example using XnView) you can clearly see the interlaced lines, also the white balance is usually completely off and the shot has green and magenta areas.

[CaronteGF]

Check if dual_iso was really enabled and working or cr2hdr is the problem. The effect of dual_iso isn't hard to see, if you zoom to 100% either in camera or on the PC (for example using XnView) you can clearly see the interlaced lines, also the white balance is usually completely off and the shot has green and magenta areas.

Tks for the tip. Dual Iso was really enable (Green Light), but the effect was not applied. I try with differents ML Nightly build, and i found the problem.

The 22 an 17 Nov just doesn´t work for me, But 25Nov works really great!. Problem Solved!

[a1ex]

Small update to cr2hdr:
- fixed cold pixel handling
- experimental DNG compression (you need to install Adobe DNG Converter; should be autodetected)

Code Select Expand


DNG compression (requires Adobe DNG Converter):
--compress      : Lossless DNG compression
--compress-lossy: Lossy DNG compression (be careful, may destroy shadow detail)


Download it from first post. It works pretty good for me (currently running it on a few thousands of pictures), but I'm still waiting for a detailed bug report for post #1602 (I could not reproduce it).

Also, auto ETTR should do slightly better choices when linked to dual ISO:
- dual ISO is only enabled by ETTR if the DR improvement is at least 1 stop (so it should no longer choose 100/200, for example)
- if the calculations result in something like 200/800, it will switch to 100/800 (better highlight protection at very small cost)

[escho]

Code Select Expand

modules/dual_iso/adobedng-bridge.c, line 39

FILE* f = popen("winepath \"C:\\Program Files\\Adobe\\Adobe DNG Converter.exe\"", "r");

In Linux 64Bit the "Program Files" are called "Program Files (x86)".

Edgar

[a1ex]

Mine is 64-bit, but under Wine I only have Program Files.

Should be OK now (all Windows search paths are now also tried via Wine).

[1%]

Also, auto ETTR should do slightly better choices when linked to dual ISO:

From testing today it seems to. I've had a few photos that are all black out of CR2HDR and I have to raise expo +5 in lightroom, almost the whole pic is half res.

[Marsu42]

I've had a few photos that are all black out of CR2HDR and I have to raise expo +5 in lightroom, almost the whole pic is half res.

But that's bound to happen if you use dual_iso to catch highlights, isn't it? Actually I'm not really sure if I'm using dual_iso correctly, but if I have a valuable very bright part that I want to expose correctly, I underexpose the dual_iso shot so much that the bright part has some definition, accepting that the dark part will loose definition as you described - mostly I'm using about +3ev in LR.