You put the question will the "A7sIII" effect the FS5? Yes a small part of the market, but for pro shooters the fact you only have 29min record time on a camera makes it's use limited. I have a FS7 and 2 Canon 1DxmkII. Maybe Sony will go for the pro market with a A9II low light, 10bit, 422 etc... spec which they can charge a pro price tag then it would be a choice of A9II - FS5 which would be similar price and compromise the line. Hope this makes sense.