The boffins at Magic Lantern have done it again — this time, successfully increasing the dynamic range of both the Canon 5D Mark III and 7D by three stops.
We've discussed the merits of the Magic Lantern firmware modification many times before. Most recently, we have seen a hack that has been able to grab 24p RAW video from Canon SLRs, while video recording capabilities have been unlocked in a fairly old SLR, the 50D.
This time around, the latest feature in the non-destructive mod is a boost to the dynamic range of the Mark III and 7D. It works by taking a photo using a sensitivity level of ISO 100 for some of the vertical lines in the frame and using ISO 1600 for the remaining lines. Then, these lines are combined back together to give an image with almost the entire dynamic range that the sensor is able to deliver — around 14 stops.
A video frame pulled from the Mark III running the new mod. The bottom-left part of the frame shows the portion taken at ISO 100, while the top-right part is with the ISO 100/1600 method.
(Credit: Alex/Magic Lantern)
Dynamic range is the ratio between the lightest and darkest parts of a photo. Image sensors on digital cameras are reasonably limited in the dynamic range they can capture, which is why photos often do not appear as vibrant as they do in reality. High dynamic range (HDR) photography is one method that some photographers use to bring out more detail and colour in a scene, but it involves capturing multiple exposures and merging them together in post-processing.
At the moment, the new Magic Lantern mod works on the Mark III for both photos and RAW video, but only for photos on the 7D. More of the technical information on the methodology can be found at photography blog Planet 5D.