Malcolm Stewart
Well-known member
I upgraded the firmware on my recently purchased MkIII yesterday, and have now had time to check out and print some of the images I took following the upgrade. (Canon UK did the sub-mirror repair last January.) I have the feeling that I am now getting the excellent results that the EF 300 f2.8L IS is renowned for, and am wondering how an upgrade of firmware could be responsible. Images shot before the upgrade and which wouldn't have challenged my 5D or 30D seemed to be not quite as sharp as I expected, or that the best focus was not where I'd expect. (Both EF 300 f2.8L IS & EF 135 f2L @ f5.6.)
Checking the timeline for the release date of Canon's recent bodies, the 1D MkIII was the first and before the 40D and 1D MkIIIs. All three had shaking of the AA filter assembly as part of their anti-dust strategy, so in one respect the 1D MkIII could be regarded as a prototype. As an electronics engineer, I know how difficult it is to control unwanted coupling between different circuits, and I am now wondering whether the problem with the pre-upgrade 1D MkIII could be that there was some unwanted but minor shake of the filter during exposure - and that the latest firmware has stopped this happening. (Other unwanted examples of this have included bars across the image from interference effects during readout etc.)
It's just a thought, and I'm offering it here for comment.
Checking the timeline for the release date of Canon's recent bodies, the 1D MkIII was the first and before the 40D and 1D MkIIIs. All three had shaking of the AA filter assembly as part of their anti-dust strategy, so in one respect the 1D MkIII could be regarded as a prototype. As an electronics engineer, I know how difficult it is to control unwanted coupling between different circuits, and I am now wondering whether the problem with the pre-upgrade 1D MkIII could be that there was some unwanted but minor shake of the filter during exposure - and that the latest firmware has stopped this happening. (Other unwanted examples of this have included bars across the image from interference effects during readout etc.)
It's just a thought, and I'm offering it here for comment.
