Hello Dual ISO gurus,
I am trying the DUAL ISO module and I would like to understand what is the optimal way of processing the DNG created by cr2hdr.
- I shot 2 pictures of the same building, one with no Dual ISO (Standard ETTR iso 100), and one with Dual ISO 100/1600.
- I processed the Dual ISO CR2 with cr2hdr default settings (drag and drop on the exe)
- I developed the two pictures using Rawtherapee 5.3 with the following settings:
Processing Profile Neutral, AMaZE Demosaicing, White Balance Daylight, Auto Levels
Below is a screen cap of some details zoomed at 100%
Left CR2 developed/ Right DualISO DNG developed
As you can hopefully see, the Dual ISO shot shows some green and magenta vertical artefacts (see for example the balconies, the window frames, or the vertical pattern in the facade). I would upload the cr2 files but I am not sure how since they are so big.
My question is :
1. What can be done to minimize these effects? Where is it the best to address them?
a. During the shot: Different settings of Dual ISO (maybe a smaller range of ISO like 100-400, or 100-800?)
b. During the conversion with cr2hdr: Different settings of cr2hdr?
c. During development of the dng: Different postprocessing in Rawtherapee (different demosaicing algorithm?)
In addition I have a few other questions with respect to Dual ISO:
2. The white balance in the Dual ISO CR2 is not the white balance that I have selected on the camera, whereas for a standard CR2 it is. Is this the expected behavior? Does this affect the processing by cr2hdr?
3. I am not sure I can evaluate in the field whether I really need Dual ISO or not. So I would like to always take 2 images of the same scene (one standard and one Dual ISO). So far I need to manually change the settings in the menu between shots to achieve this. Is there a possibility to set up the camera to take automatically 2 images in a row: one standard image with current settings (base ISO) and one Dual ISO image? That would make the process more convenient.
Thanks for your help.
Config:
ML for 6D Build 2017-12-07
cr2hdr Build 2017-12-04
I am trying the DUAL ISO module and I would like to understand what is the optimal way of processing the DNG created by cr2hdr.
- I shot 2 pictures of the same building, one with no Dual ISO (Standard ETTR iso 100), and one with Dual ISO 100/1600.
- I processed the Dual ISO CR2 with cr2hdr default settings (drag and drop on the exe)
- I developed the two pictures using Rawtherapee 5.3 with the following settings:
Processing Profile Neutral, AMaZE Demosaicing, White Balance Daylight, Auto Levels
Below is a screen cap of some details zoomed at 100%
Left CR2 developed/ Right DualISO DNG developed
As you can hopefully see, the Dual ISO shot shows some green and magenta vertical artefacts (see for example the balconies, the window frames, or the vertical pattern in the facade). I would upload the cr2 files but I am not sure how since they are so big.
My question is :
1. What can be done to minimize these effects? Where is it the best to address them?
a. During the shot: Different settings of Dual ISO (maybe a smaller range of ISO like 100-400, or 100-800?)
b. During the conversion with cr2hdr: Different settings of cr2hdr?
c. During development of the dng: Different postprocessing in Rawtherapee (different demosaicing algorithm?)
In addition I have a few other questions with respect to Dual ISO:
2. The white balance in the Dual ISO CR2 is not the white balance that I have selected on the camera, whereas for a standard CR2 it is. Is this the expected behavior? Does this affect the processing by cr2hdr?
3. I am not sure I can evaluate in the field whether I really need Dual ISO or not. So I would like to always take 2 images of the same scene (one standard and one Dual ISO). So far I need to manually change the settings in the menu between shots to achieve this. Is there a possibility to set up the camera to take automatically 2 images in a row: one standard image with current settings (base ISO) and one Dual ISO image? That would make the process more convenient.
Thanks for your help.
Config:
ML for 6D Build 2017-12-07
cr2hdr Build 2017-12-04