4K bitrate for Sony A7rII?

[Daniel D. Teoli Jr.]

I read this from another forum. I was looking for how much 4K video you can out on a 32 gb card. Is the native video in the Sony the highest quality 4K or do I need to adjust the settings? I heard about bitrate, but never paid attention to it until reading this. 

"Things like sensor size, framerate and resolution of the video doesn't affect how much you can record to your memory card, it's the video bitrate per second that does. Basically if you have a camera capable of recording 1080p 60fps at 100Mbps you'd be able to fit exactly the same amount of video on your memory card as if you're recording 4K 25fps at 100Mps.

I have a Sony RX100 IV which is capable of recording 4K video at 100Mbps bitrate. On a 64GB SDXC card that gives me around 1 hour and 20 mins of recording time. As far as I know the GX85 is also capable of recording 100Mbps 4K so you'd be looking at around the same time. Some cameras have the option to dial down the bitrate (on my RX100 IV you can opt for recording 4K at 60Mbps) which will give you more recording time on your memory card (2h11m). Obviously the video will be more heavily compressed as a result.

Make sure you have fast enough memory cards for recording 4K by the way as some cards, even SDXC U-3 cards aren't fast enough for recording at 100Mbps."

 

Thanks

[Robin R Probyn]

Sony A7 series camera are 8 bit.. recording.. you can record to an ext recorder for a different codec but the bit rate is only 8 bit.. 420..  4K is 100Mbps max..  definitely the card will have less recording time in 4K than HD.. as in any camera .. at the same frame rate.. I would go with at least 64GB for 4K .. the camera will stop after 29mins 59 seconds anyway..