Author Topic: Best AutoETTR settings with Dual-ISO for always Dual-ISO more DARK/LIGHT photos  (Read 3068 times)

xorpi

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Hello,

I'm using dual-iso + AutoETTR modes in Magic Lanten and Canon 700D (THANKS GOD FOR DUAL-ISO!!!). When I try to merge the images Dual-ISO files with classical raw files (AutoETTR) together using AuroraHDR, it fails with message about wrong resolution in one of the pictures. LR HDR doesn't work either. I'm converting cr2 files to dng same problem with dual-iso dng + AutoETTR classical raw files/dng

files:

https://dl.dropboxusercontent.com/u/3673771/DualISOAutoETTR.zip

Errors:

https://dl.dropboxusercontent.com/u/3673771/ErrorsMerge.zip


Do you know what might be wrong?


I have AutoETTR on Auto mode. Can you tell me what are the best settings in AutoETTR so that dual iso makes as many different Ev images (Dark / Bright) as possible? How to make focus-stacking dual-iso shots?

What settings to use for always on dual-iso so that it makes as many Ev shots as possible (or Dark/Light shots)? Would it be possible to add a feature to dual-iso to do more Dark+Light shots automatically with different Ev - LIKE ADVANCED HDR ?

I really LOVE MAGIC LANTERN + DUAL- ISO!! :)
Think Dynamic! #HDR #BW 📸

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josepvm

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I really do not understand what are you trying to do: merge Dual-ISO processed DNG's with regular CR2 files in an HDR software? What is the interest of doing this?

Dual-ISO is useful to get a wide dynamic range when bracketed regular pictures are not possible (moving subjects). But if you are already doing bracketed exposures to make an HDR, you can simply turn Dual-ISO off.

And yes, a DNG from a a processed Dual-ISO picture has a slighlty different resolution than a regular CR2 file, the outer lines are cropped. If you really need to merge both files, you can convert both to TIFF 16 bit, open them in an image editor (Photoshop, GIMP, etc.) and crop one of them to the exact size of the other one. After that, you can merge both TIFF normally in your HDR software.

And I do not understand how these questions are related with ETTR settings. And how ETTR settings could affect how Dual-ISO module makes more or less images ... Dual-ISO is a single shot, not a bracketed series. And as I already said, I do not see the point of using Dual-ISO if you are shooting bracketed series.

And focus-stacking Dual-ISO pictures is exactly the same as focus-stacking regular pictures, read the forum and try to master focus-stacking alone first.
 

xorpi

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I want bracket Dual-ISO files after convert to .dng  (Dark/Bright version together) like this one:

https://www.facebook.com/FRANOPHOTO/photos/a.1079523578754449.1073741826.167020016671481/1079523835421090/?type=3&size=2048%2C1373&fbid=1079523835421090

and:

https://www.facebook.com/FRANOPHOTO/photos/a.1079525722087568.1073741827.167020016671481/1079525808754226/?type=3&size=3104%2C1350&fbid=1079525808754226

With more different Ev in dual-iso files (more Dual-ISO shots wit different Ev with AutoETTR settings) like Advanced HDR bracketing. - I love Dual-iso for better dynamic range and colors, shades, etc...
Think Dynamic! #HDR #BW 📸

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josepvm

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You can bracket Dual-ISO exposures easily:

1- Find a static scene (landscape, etc) and mount your camera on a tripod.
2 - Set camera to M mode, chose the aperture value you prefer. Set Dual-ISO as active.
3- Enter LiveView, use A-ETTR to find the shutter speed value that maximizes exposure without clipping any highlights. This will be the base exposure for bracketing.
4- Exit Liveview, enter ML menu and setup Advanced bracket options (number of desired frames, EV increment) and choose as "sequence" the option "0 + ++". Setting the 2-second delay is useful also to avoid camera shake when starting the bracketed series.
5 - Press the shutter release to start taking pictures.
6- In your computer convert all Dual-ISO CR2 files to DNG with cr2hdr.
7- Process the DNG files corresponding to a bracketed series with your preferred HDR sofware.

That workflow will work, I see no problem in it (be careful to do not mix processed DNG files with original .CR2 files in your HDR sofware, as you were previously attempting).

But ... Dual-ISO files have a wider dynamic range at a expense of lower resolution. And they do not have better color.

So is preferable to use exactly the same workflow with Dual-ISO disabled, skipping number 6 and feeding your HDR software with regular .CR2 files. You will only need to increase the number of desired frames in Advanced bracket to cover the same dynamic range. And the resolution will be better. So I can't see any real interest in using Dual-ISO in this scenario.

xorpi

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No.  Advanced Bracket  with Dual-iso doesn't work. 
Think Dynamic! #HDR #BW 📸

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josepvm

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It works for me in three different cameras; EOS 500D, EOS 50D and EOS-M.

So please, be more especific: why do you say "It doesn't work"? 

You can't activate Advanced Bracket when Dual-ISO is enabled? Or it does not take pictures at all? Does it work when you disable Dual-ISO?

Or the problem is with the flies? You cannot process them with cr2hdr? Or they are not properly bracketed?

We need more info to be able to help you.