Can jrista take account of the heavy AA filters on Canon sensors in his calcs or have I missed something?
Well first, as I've mentioned in the past, I believe the idea that Canon uses overly strong AA filters is a bit overblown. I thought my 7D had an aggressive AA filter until I first put on the EF 300mm f/2.8 L II in August 2012. I'd been using a 16-35 L II and the 100-400 L. Both are "good" lenses, but neither is a truly "great" lens. Both don't seem to have enough resolving power and/or contrast to really do the 7D justice. They get really close, but often enough they fall just a little short, which produces that well-known "soft" look to 7D images.
With the F 300/2.8 II, 500/4 II, and 600/4 II, with and without 1.4x and 2x TCs, the IQ of the 7D is stellar. I've never seen any of the classic softness that I did with my other lenses. Based on the IQ from using Canons better lenses, I do NOT believe they have aggressive AA filters...I think they actually have AA filters that are just right!
On pentaxforums you will see comparisons between the K5-II and the filterless K5-IIs. Both have same 16Mp sensors but the -IIs is a whole lot sharper and is claimed to be equivalent to a filtered 24Mp camera.
Does this matter in the real world? Well yes maybe if you want to use 100pc crops.
Will Canon introduce something like the D7100 in their well trailed up coming 7D2, 70D, 700D series?
Somehow doubt it.
Excellent stuff jrista - thanks for posting.
I'm curious about the difference with the Pentax K5 II. If there is that much of a difference, I'd presume that the AA filter WAS aggressive. From what I have heard, the D800 and D800E, when you use a good lens, does NOT exhibit that much of a difference. In many reviews I've read, the differences were sometimes barely perceptible, with the added cost on the D800E that if you shoot anything with repeating patterns, you can end up with aliasing and moire. There is definitely some improvement to shooting without an AA filter, but I am not sure it is really all it is cracked up to be.
Generally speaking, I would blame the lens for any general softness unless it is definitively proven to outresolve the sensor. For sensors with the densities they have today, lenses are generally only capable of outresolving the sensor in a fairly narrow band of aperture settings...from around f/3.5 to f/8 for FF sensors, and f/3.5 to f/5.6 for APS-C sensors. The higher the density of the sensor, the narrower the range....a 24mp APS-C can probably only be outresolved at around f/4, unless the lens is more diffraction-limited at wider apertures. Wider than f/3.5 in the majority of cases, optical aberrations cause softening, in many cases much more than you experience from diffraction even at f/22.
That said, so long as you pair a high quality lens with a high density sensor on a Canon camera, or for that matter a Nikon camera, I do not believe the AA filter will ever be a serious problem. When it comes to other brands, I don't really know enough. In the case of the K5 II, it really sounds more like the AA version DOES have an aggressive filter, which is why there is a large difference between the AA and non-AA versions.
On pentaxforums you will see comparisons between the K5-II and the filterless K5-IIs. Both have same 16Mp sensors but the -IIs is a whole lot sharper and is claimed to be equivalent to a filtered 24Mp camera.If you check out luminous-landscape.com there is a nice thread comparing optimally sharpened D800 vs optimally sharpened D800E. I believe the conclusion is that for low-noise situations, the performance is virtually identical.
Aye, this is what I've heard as well. There is a small improvement with the D800E in the right circumstances, but overall it does not seem to be as great as it otherwise sounds on paper. Given the IQ I can get out of the 7D, which does have an AA filter, with top-shelf lenses...I really do not believe it has an aggressive AA filter, and I am quite thankful that the AA filter is there. Without it, I'd never be able to photograph birds...their feathers are moire hell!