Say I take one image at F=8.0, 1/100sec and 200iso, by metering to brighest element in the scene.
I want to create +2EV and -2EV images out of the above image. Which module is ideally suited for generating these images?. I think, it is Exposure module. Please confirm.
Thanks
Yes, Exposure.
Keep in mind, with any software Exposure tool you’re not really modifying the exposure, that was locked when the image was recorded in the camera. If you spot-metered the brightest part of the scene, you effectively set that at middle-gray, so you should have room to push your data +2EV without clipping at the top. However, you’ll probably notice noise in the shadows as more of them were placed below the noise floor of the sensor at the time of exposure.
You should try the Exposure Fusion options in the Base Curve module: compressing dynamic range with exposure fusion | darktable
Yes, I would simple use the exposure module.
Thanks everyone.
I did not know about Fusion capability of BaseModule. I made few samples with it. That is exactly what I wanted. But then I looked at the noise. I think that is too much. I already have several bracketed shots. I compared the EV-boosted shot against bracketed shot. The difference was huge, so decided against this strategy 
I am attaching the comparison.
