I received my Sony FS7 in mid January and have been familiarizing myself with its capabilities. Its first two jobs, a commercial and BTS, demonstrated both its versatility and usability in the field. However, this past week required two-cameras on an industrial shoot. I knew I wouldn't get a chance to correct the footage myself, and I wanted to deliver footage usable footage straight out of camera so as to avoid having the client feel the need to toss on heavy-handed Magic Bullet filters (as they have in the past when I'd shot with a WideDR profile on C100).
Excited to use my new FS7 but unable to rent a second body due to budget, I opted to use my A7S as the B-camera. The trick was to find the right settings that would get both cameras as close as possible. Setting both cameras to SLOG2 was not a desireable option (as I preferred to avoid the client grading themselves without my guidance), and with approximately 35pgs/day to cover, the extremely fast pace of this particular shoot would not afford me the ability to spend much time at video village ensuring the images and exposures match. As such, I needed to find Rec709-friendly profile settings that would allow me to light, grab a reading, and call out a stop to the B-cam Op and shoot (the director loves to shoot the rehearsals, which if the actors got their lines clean, was sometimes the only take we got). I custom White-Balanced both cameras to a common white reference at the head of each scene, and while not 100% matched, I feel we got pretty close, with minimal tweaks needed for a perfect match. Below are the resulting settings I used with screenshots. FS7 are the wides, A7S are the CUs.
FS7: 2000 ISO / HG7
A7S: 400 ISO / Cine4, Cinema color
Yes, I did find it odd that I had to set the A7S at 400 ISO to match FS7's exposure at 2000 ISO. Beats me, but I rated my light meter at 2000 ISO (as was the FS7), and the resulting T-stop made both cameras match each other well.