FS7: Long Form: Codec Quandary

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digitalinnovations

Well-known member
I have my first, long form shoot with my FS7 next week and I'm caught in a dilemma: the client informed me that the live event should be less than hour and I've got 64 gig cards. I'm also shooting C100 as my B-Cam so I need to shoot S-Log to help match in post. So that puts me in an awkward position in choosing the right codec; I may be able to shoot UHD and fit them on the two cards but that remains to be seen. I'll be delivering in HD but would like the UHD for reframing in post but I also need to color correct so I need a codec that can stand up to that.

Any one have real world experience in such a situation? It seems I can shoot UHD in XAVC-L but the 4:2:0 may fall part OR I could shoot XAVC-I but in 1080 and lose the ability to reframe. Am I missing something? Suggestions?
 
From what Ive read XAVC L UHD takes a lot of computer grunt to handle.. and if its only going to be 4 2 0 anyway.. XAVC i in 4 2 2 1080 seems a much better option all round.. at the expense of re framing.. but how much of that are you going to do anyway..
 
I would shoot it in FHD XAVC-L 50mbps. You have 10-bit 422 and smaller files to handle and your 64 card will hold it all. With two cameras rolling there's no need to reframe in post.
 
The compression artefacts will be the biggest limitation to grading not the 8 bit 420. From what little shooting in XAVC L I've done it seems surprisingly good but it'll depend on what the event is you're shooting. If it's a confetti festival you might struggle.
 
My recommendation is to use XAVC-L UHD with a WYSIWYG scene file in custom, but take the time to match the cameras prior to the shoot so no grading will be necessary.
 
Thanks everyone! Sounds like 1080 is the way to go. I've got four 64gig cards on hand so I should be able to record the 1080 in one of the better codecs over two cards.
 
I did some testing with XAVC-L 1080 and burned in the HG7 LUT. Looks fantastic. Surprised at the wideness of the latitude. For a long form event, this would indeed be the way to go. Plays well, even on my ancient quad core from 2007. I'd go with Doug's recommendation here.
 
Actually my recommendation in post #6 was to shoot UHD so that he'd have the ability to crop in 50% (almost like having a third camera).

In summary: Choose/create a nice WYSIWYG scene file on the FS7 that gets you very close to a final image because you don't want to be grading 8-bit 420 XAVC-L UHD in post. S-LOG would be a terrible choice. And then create a matching scene file for the C100, or come as close as you can and then plan on just touching it up to match closer in post. Once again, you don't want to be shooting LOG on the C100 because it is an 8-bit codec (please correct me if I am wrong on that point). You save yourself a lot of grading time and rendering, you get UHD for the FS7's angle, and you don't need much more storage space than if you were shooting HD with other cameras. That's how I'd approach a shoot like this.
 
basspig said:
I did some testing with XAVC-L 1080 and burned in the HG7 LUT. Looks fantastic. Surprised at the wideness of the latitude. For a long form event, this would indeed be the way to go. Plays well, even on my ancient quad core from 2007. I'd go with Doug's recommendation here.
Click to expand...

Would that be a wise choice as I'm needing to match my B-Cam?
 
Waitaminute.. I read somewhere that the XAVC-L was 422 10-bit. Only the MPEG422 is 8-bit.

Sony's block states:

The PXW-FS7 is compatible with Sony´s new XAVC Intra and XAVC Long GOP formats, each supporting 10-bit 4:2:2 recording (XAVC-I, 180fps; XAVC-L, 120fps).
 
basspig said:
Waitaminute.. I read somewhere that the XAVC-L was 422 10-bit. Only the MPEG422 is 8-bit.

Sony's block states:

The PXW-FS7 is compatible with Sony´s new XAVC Intra and XAVC Long GOP formats, each supporting 10-bit 4:2:2 recording (XAVC-I, 180fps; XAVC-L, 120fps).
Click to expand...

The 1080P XAVC-L is 422 10bit. The 4k/UHD XAVC-L is 420 8bit. That's what I'd read elsewhere.
 
basspig said:
Waitaminute.. I read somewhere that the XAVC-L was 422 10-bit. Only the MPEG422 is 8-bit.

Sony's block states:

The PXW-FS7 is compatible with Sony´s new XAVC Intra and XAVC Long GOP formats, each supporting 10-bit 4:2:2 recording (XAVC-I, 180fps; XAVC-L, 120fps).
Click to expand...


My understanding is XAVC-I and XAVC-L are both 10 bit 422 in 1080 but XAVC-L drops to 8 bit 420 in UHD. Otherwise, I'd use the XAVC-L codec in UHD for this particular shoot.
 
That is true. That's why I recommended shooting XAVC-L UHD while burning in a WYSIWYG scene file. If you don't have to grade, the limitations of 8-bit 420 don't matter at all. But the benefit is that you get a 4K frame size at a very low bit rate.
 
Doug Jensen said:
That is true. That's why I recommended shooting XAVC-L UHD while burning in a WYSIWYG scene file. If you don't have to grade, the limitations of 8-bit 420 don't matter at all. But the benefit is that you get a 4K frame size at a very low bit rate.
Click to expand...

I don't disagree that using that method would save time in post but unfortunately I don't have the time prior to try to match the two cameras up so I will have to "pay the toll" in post instead of before hand...Either way you pay I guess :)

However, I do intend on trying to create a matching scene file for my C100 as soon as I can.
 
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