Magic Lantern and Dual-ISO

ziggy53ziggy53 Super Moderators Posts: 24,156 moderator
edited February 18, 2014 in Technique
Magic Lantern is an overlay software for camera firmware, specifically for many late-model Canon dSLRs. While it has features relating to video capture, it also has many features relating to still image capture.

One of the more recent still image features is "Dual-ISO". Basically, you use Magic Lantern to load 2 - different ISOs; a "Base ISO" and a "Recovery ISO". A common outdoor setting would be a base ISO of 100 and a recovery ISO of 800 or 1600. What Magic Lantern does is to capture every other scan line at the alternate ISO, yielding dramatically extended Dynamic Range. The downside is a loss in vertical resolution, although it's not as bad as it sounds since you still sample all scan lines to create the final image resolution.

A very recent addition to this feature is that the image EXIF also adds a "Dual-ISO" tag which is searchable on some image sharing sites, so you can search for example images. Notably Flickr has this working nicely:

http://www.flickr.com/search/?q=%22Dual-ISO%22&m=tags

While I haven't been able to get the same results through SmugMug yet, know that I am on it like bald on a cue ball. :wink (Possibly there just aren't any examples there yet.)

For those brave enough to risk their Canon dSLR and try the Magic Lantern overlay software:

http://www.magiclantern.fm/

Supported cameras (not all features available with all cameras), 5D2, 5D3, 6D, 7D, 50D, 60D, 500D (T1i), 550D (T2i), 600D (T3i), 650D (T4i), 700D (T5i), 1100D (T3), EOS M, 100D (SL1)
ziggy53
Moderator of the Cameras and Accessories forums

Comments

  • ziggy53ziggy53 Super Moderators Posts: 24,156 moderator
    edited February 18, 2014
    It turns out there are some SmugMuggers using Dual-ISO:

    https://www.google.com/#q=site%3Asmugmug.com+%22Dual-ISO%22
    ziggy53
    Moderator of the Cameras and Accessories forums
  • pathfinderpathfinder Super Moderators Posts: 14,708 moderator
    edited February 18, 2014
    Here are a few (4) images on a smugmug site demonstrating the Dual ISO technique. http://hershy.smugmug.com/keyword/dual/i-scbDSsD

    I could not get your link to work for me, directly it just gave me a list of links, some of which had no images Ziggy.

    14 stops of dynamic range will certainly be quite useful, if it does not entail too much in the way of other costs.

    When I shoot 3 frame HDRs, I frequently find I can discard one frame, and end up with just two images to merge. Still there is some delay between frames which the dual ISO techniques discards, so it bears further study. I have a 5DMk2 that I could try this on I think.

    I think this belongs in Shooting Technique, more than Finishing School, so I will move it to Technique now
    Pathfinder - www.pathfinder.smugmug.com

    Moderator of the Technique Forum and Finishing School on Dgrin
Sign In or Register to comment.