Full frame DSLR: depth of field and vignetting
I’ve recently become the (very happy) owner of a second hand Canon EOS 5D, and despite the camera being 5 years old this year the difference between it and my previous Canon EOS 20D is stunning. One unexpected change was the difference in the depth of field at any given f-stop between a full-frame and APS-C sensor: take a look at this review page for a clear summary, but that (like the dimensions of a mobile phone) didn’t mean much until I started shooting with it.
I have done a lot of 35mm photography (along with 110, 126 and some medium format), more years, infact, than I have been shooting digital, so I can’t say for sure if my DoF expectations have been coloured by my early shooting, or if it’s simply that the whole relationship between f-stop of DoF just feels more natural at 35mm. I’m leaning towards my own experience colouring my judgement, as medium format photographers probably regard 35mm DoF as hideously deep…
There’s no 20D vs 5D pictures here, just a selection of 5D images taken with a Canon 17-40mm f4 L and a 50mm f1.8 with some post-processing has been done in Aperture 2 (click for a larger set):
The vignetting is also a lot more pronounced, especially at the 17mm end of the 17-40. Again, nothing too surprising on paper, and the subject of many press-releases since the 5D came out from Canon and other manufacturers, carefully describing the latest improvement in micro-lenses or sensor pit depths. The 50mm example fares much better than the wide images, again, not surprisingly.
Does the darkening impact my photography ? Not that much, actually. I’ve not been shooting for that long with the camera, but I have to admit to an almost unhealthy addiction to the Vignette tool in Aperture when processing my 20D images so for the most part the edges are acceptable to me (I would very much like to upgrade to Aperture 3 so that I can de-vignette in post when the images calls for it, but so far the experience of the trial version has left me unable to do so).