Does anyone know what the meaningful differences between 3-line comb filters and 5-line are? I just dug out a YCS-100 that I haven't used in forever and I've forever and I would have to say it's the best 2D comb filter I've seen. It uses a 5-line comb filter. All the other 2D filters I've seen are 3-line. Are 5-line really significantly better, or is this just a good implementation?

I read somewhere a while back that the difference between a 2-line filter and a 3-line filter is that the number describes how many horizontal lines the filter handles at a time when processing. Don't know how true that is, but if that is the case, we can only assume that the 5-line processes 5 lines at a time?

Yeah - 3-line filters look only one line in the field above and below, while 5-lines look two away. Given the same quality a 5-line one will make fewer errors, but if it's not adaptive it might have more artifacts...