The new firmware is said to have been produced in response to customer feedback, and will allow manual control of the aperture, shutter speed and ISO sensitivity equivalent when shooting video. Previously, all three variables were controlled automatically, with the only user input available being the ability to specify exposure compensation during video recording - with no input over which variables were changed to what degree to yield the new exposure level. A full selection of apertures will now be possible, while available shutter speeds will range from 1/30th to 1/4000th second. ISO sensitivity selections will include Auto, ISO 100 to 6,400 equivalents, and H1 (ISO 12,800 equivalent).

The shutter speed range being offered is much wider than that originally available under automatic control, with the current 5D Mark II firmware limited to a range from 1/30th to 1/125th second. The firmware apparently won't allow access to the camera's minimum ISO L or maximum H2 settings (ISO 50 and 25,600 equivalents respectively) during video recording. We're not certain exactly what ISO range was previously possible, but the ability to specify a fixed ISO sensitivity is a definite step forward regardless of whether the range has been expanded or not.

It isn't immediately clear from the information available to us whether these exposure variables will be fixed from the start of video capture, or if adjustment will be possible during capture. It also isn't clear whether manual control of aperture also necessitates manual shutter speed selection (and vice versa), or whether it will be possible for only one variable to be specified. Likewise, we're not currently sure whether specifying a manual ISO sensitivity will still allow automatic control of shutter speed / aperture. We've got an email pending with Canon to confirm these points.

The firmware isn't currently available, with Canon USA expecting delivery in "early June 2009", while Canon Europe is more precisely promising the firmware will be available on June 2nd, 2009. Look for more details on our news page, just as soon as they're available.

UPDATED 2009-05-27 11:09ET: Added Canon Europe press release.

UPDATED 2009-05-27 12:17ET: We've received confirmation on a couple of points from Canon. Most importantly, the new firmware solely adds completely manual capability. What this means is that if the user opts to specify one setting, they must also specify the others. It won't be possible to, say, manually specify the aperture without also selecting the shutter speed and ISO sensitivity. The same is true of ISO sensitivity - the camera won't select the shutter and aperture automatically once the ISO setting is manually specified.

Another point Canon clarified for us is that the ISO sensitivity range has not been changed from the previous firmware. The range of ISO sensitivity choices available to the user in the new firmware mirrors those that were available previously under automatic control.

One question that remains outstanding is whether or not the ISO sensitivity, shutter speed or aperture can be changed during video recording. This information should be available closer to the actual firmware release. We understand that Canon USA is tentatively shooting for the same June 2nd release date that has been announced by Canon Europe.

Watch our news page for further information as it is announced by Canon.