I agree that a larger sensor is inherently more difficult to focus compared to a smaller sensor, but what also matters is the lens.
Nauticam has just announced their housing for the G7X, and seem to agree with Scott G. that the G7X is better than the RX100 for macro:
"Most interesting to underwater photographers is the excellent macro performance of G7 X when used with accessory macro conversion lenses. G7 X can capture significantly smaller subjects than Sony's RX100 series. The only current cameras that we've tested offering better closeup performance are the smaller sensor Canon G16 and S120."
What is also interesting is that they are planning a compact macro converter wet lens, sort of a baby brother to the SMC. The sample picture using a prototype lens by Alex Tattersall is very impressive! Canon G7 X, now available! ? Nauticam USA
Also interesting is their new port system. If you want to shoot wide, you can get a shorter port that limits zoom. I guess there will always be a trade-off between versatility and image quality. Although the G7X looses some versatility (in terms of being able to shoot wide and macro on same dive) compared to compacts with smaller sensors, the image quality is getting better!
Nauticam has just announced their housing for the G7X, and seem to agree with Scott G. that the G7X is better than the RX100 for macro:
"Most interesting to underwater photographers is the excellent macro performance of G7 X when used with accessory macro conversion lenses. G7 X can capture significantly smaller subjects than Sony's RX100 series. The only current cameras that we've tested offering better closeup performance are the smaller sensor Canon G16 and S120."
What is also interesting is that they are planning a compact macro converter wet lens, sort of a baby brother to the SMC. The sample picture using a prototype lens by Alex Tattersall is very impressive! Canon G7 X, now available! ? Nauticam USA
Also interesting is their new port system. If you want to shoot wide, you can get a shorter port that limits zoom. I guess there will always be a trade-off between versatility and image quality. Although the G7X looses some versatility (in terms of being able to shoot wide and macro on same dive) compared to compacts with smaller sensors, the image quality is getting better!