Sony FX9 codec/resolution question

[Ray Rushing]

I'm doing prep for a show that's starting next month and trying to make some decisions about codecs and resolution. Unfortunately this is a doc series and we will need to make concessions for storage/post.  We will likely be shooting on a Sony FX9. I'm wondering is it better to shoot XAVC-I at 1920x1080 or XAVC-L at UHD? XAVC-I is 350mb/s and XAVC-L is 100mb/s. So which is more important to the quality and color of the image? Resolution or Data Rate?

[Bruno Mansi]

I guess if this is a programme that has a limited life (broadcast once and then never seen again) then shooting at HD is a reasonable option.

But if you have any reason to think it might have future sales potential, then the sensible thing would be  to shoot UHD.

I get the feeling that shooting UHD (and above) is becoming almost mandatory for any production with a reasonable budget. I realise that filming documentary can result in huge mounts of rushes and this could put a strain on the budget in terms of storage.

I've worked on docs where the interviews were shot at around 5K on RED, but a lot of the archive/clandestine recordings etc. were still sourced at HD - sometimes because this was all that was available.  The reasoning  was that you could still create a UHD version of the programme as it would be acceptable to up-rez the archive. If 35mm prints are available, you could always have these rescanned at 4K, but this is hugely expensive.

Of course, you have to make sure the broadcaster is happy with this arrangement, but most of them accept that archive is often not available in anything above HD and make allowances for this. They may well stipulate what sort of up-rezzing they will accept.

I think most colourists would want to work with 10 bit codecs where possible, but that is also going to impact on data rates!