Hi Peter,
I've found that to get the best out of the files we need to be a bit more fussy about the conversion and processing decisions we make.
The 7D's sensor has a little "quirk" which causes some folk IQ problems, in that it has (in common with sensors from a lot of other manufacturers - no idea about the whys and wherefores, but it's a common enough thing) a "green channel imbalance" - basically the output of the two green channels isn't perfectly matched. I understand that this isn't an accidental design decision or a fault
per se, but I don't know what benefits - if any - it delivers. If the readout difference between the two green channels is beyond a certain limit, and depending on the demosaicing algorithm being used (DCRAW has had a demosaicing option specifically designed for this imbalance for years, and my old favourite Raw Therapee manages it very well too), it can cause a "maze" effect in the files which can look like noise - although usually at 200% view, with Levels through the roof and a heinous level of sharpening!
It needs to be said that the issue is at its worst by far in files converted in say, ACR 5.5 and Lr 2.5 (I think), but as I suggest, some converters deal with the imbalance extremely well - I use Cap One 5 for my 7D files, and although if I really zoom in I can see
something of the effect of this annoyance in featureless areas of the file, it is irrelevant in reality, and finished processed files look great at any ISO.
That said, I've been using selective sharpening of converted files since not long after I got the 40D, and that's a good idea for the 7D too.
I will say that Adobe are well aware of the green channel imbalance thing, and although they've efectively ignored it for years (much to the chagrin of Olympus, Minolta, Panasonic and some Sony users, all of whose cameras can exhibit the maze effect) the introduction of the 7D has prompted Adobe to explicitly address it, hence the new demosaicing algorithm in the Lr 3 betas: and I have to say (as someone who has long hated the conversions from Lr 2.x and ACR) that the latest beta is
fantastic on 7D files - I'm
this close to becoming a fully-fledged Lr fan.
And ACR will presumably get the same algorithm in its next release.
So that's what I mean, Peter - it's easy enough to get great results from the 7D, but for some folk it might mean taking a critical look at their current workflow.
I'm lucky in that my 40D workflow works really well for the 7D - I needed to make less adjustments this time round than I did going from the 30D to the 40D. Indeed, I'd probably still use Raw Therapee fo rthe 7D, but version 3 (the one that suppots the 7D) is
very "alpha release" at the moment and is effectively unusable. Besides, Cap One's sharpening is better.
