Repeatedly I have concluded that CCD sensors are superior to CMOS, especially when it comes to special false-color IR styles. With normal, “straight-forward” IR like 720nm or monochrome, I don’t really notice a difference, but when it comes to, say, digital Aerochrome with Midwest Optics’ triple-bandpass filter, the differences are striking.
I had really lousy results with the Nikon D7100 and newly with the Nikon D600, which both have a modern CMOS sensor. Weird blur, focusing problems and also weird colors, lack of contrast and so on.
Things were much better with the Nikon D40. Amazing how good these older models are for false color IR. I wish there were CCD Nikons with greater resolution than 6MP or 10MP.
I shot raw, took the white balance on healthy green grass, then channel mixer with IR subtraction (-50 each on green and blue), then back into the raw converter to tweak the white balance.
In this comparison, the differences become obvious. Above: Nikon D40x with CCD sensor, below Nikon D600 with CMOS. Both with the same presets, both white balance around 2750 Kelvin. And importantly, this is without IR subtraction, neither in the RAW converter, nor in the channel mixer: