C300: C300III recording modes

boosh

boosh

Well-known member
Hi all,

I just wondered if anyone has done any in depth testing with the various recording modes on the C300III? I've watched Undones review oft he C300III and saw how he rated the All-I very similar, if not better than the 10 bit Raw light, but not as good as the 12 bit Raw light. My question is about the difference between All-I and Long GOP. How much of a difference is there? The data rates of All-I would be ideal for me and I know the quality will be somewhat better but I was only sent one 256GB card with my C300III and have to wait for the 512GB to arrive and in the mean time I have three days filming lined up next week I'd like to use my C300III on. Will Long GOP suffice or should I output from the HDMI to Prores in my Ninja-V? Would that even be any better?

Thanks.
 
I haven't seen long-GOP vs all-I tests from the C300III, but I bet the long-GOP is fine.

I have no issues shooting long-GOP on my GH5 or FS7. In theory, all-I might give you a clearer picture on a fast-moving detailed scene (like waterfall footage?) But in practice I think the visible difference is negligible.

I care a LOT more about 10-bit vs 8-bit than I do about all-I vs long-GOP.

That being said, I'd be nervous to only have 1 card with me and then would definitely want to have the ninja-v as a backup option.
 
Thanks ahalpert, it's interesting as the C300III is only H.264 but even the GH5 is H.265. I assume Long-GOP in H.265 would be higher quality? I'm going to run some tests myself and check the quality!
 
Well usually when they do H265, they shrink down the bitrate. So the quality should stay the same but you just get smaller filesizes.

I just double-checked, and GH5 4K H.265 is 72Mbps while it shoots a 6K 4:3 mode at 200Mbps.

So, maybe if you shot H.265 at the same bitrate as H.264, it would look better? I'm not sure, though, because I've read that H.265 compression is more effective at smaller file sizes. (In other words, if you're cramming 4K down to 100Mbps or lower, you will get a better image with H.265 than with H.264. If you're shooting it at 200Mbps or 400Mbps, you may not see a difference.)

One last thing to note is editing speed. One reason to use All-I instead of Long-GOP is that all-I should be easier for your computer to playback. (But I don't have a top-of-the-line macbook pro and it has no problem with long-GOP.) Similarly, H.264 will be easier to playback than H.265.

Now, a lot of that ease or difficulty comes down to hardware acceleration - does your graphics card have built-in H.264 or H.265 decoding?

Most graphics cards in use now have H.264 decoding because H.264 has been around for a while. Only some graphics cards have H.265 decoding.

So generally, I think that H.264 Long-GOP is a good way to go for now to balance file sizes and editing playback speed.
 
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