FS700 with booster to get full frame vs one of the FF A7 cameras. What I lose? Sure I know I lose smaller size and stupid high iso. But is that it? And what is recommended recorder to get max. quality and features from FS700?
The FS700 you get RAW 4K recording, 10 bit recording, RAW high frame rates. Image quality wise its leagues ahead of the A7 series.
That said the A7 series is great for gimbals. The A7III has amazing auto focus if that helps with your work. Of course being able to shoot up to 12,000 iso or so and still get a clean image is nice. Keep in mind those cameras do use heavy noise reduction in camera. Of course you are limited by the 8bit codec and color science.