Intra or Long GOP 1080P, and 25P/24P video questions

[Jon O'Brien]

The story so far: last year I started filming with digital cameras. Previously I had experience with Super 8 and 16mm film only, and digital was something completely new to me (other than brief videos shot on my phone). My first digital filming was with the Canon C200, shooting in MP4, and now I'm delving into the C300III. The C300III doesn't have an MP4 filming option but it does have XF-AVC 1080P intra-frame or Long GOP recording capability.

I started out with the C300 shooting 4K, just brief shots (and thus smallish files), and getting into color grading for the first time, and so far my experiences have been good, but after realising how large the file sizes are going to be for serious filming, and after doing a bit more research, I've decided to go back to 1080P shooting with the C300 for the time being. At least to get started with the C300. I have some people interested in me making some video content for them soon.

I live in Australia where the video standard is 25P, PAL, 50 Hz. I finished a cinematography course last year and we shot everything in the course at 25P. I asked the lecturer would we ever choose 24P for shooting and he said only for feature film production that might be destined for worldwide distribution.

The main client I will hopefully be shooting some videos for soon has a youtube channel that they post all their video content to. So it seems to me that shooting in 1080 will be fine for that. There is no need for VFX or any cropping/zooming in post.

Here are my questions, and if anyone can help me with answers or any other advice I'd be grateful. Of the two options for 1080P filming I can choose 160Mbps intra-frame, or 50 Mpbs Long GOP on the camera settings. What is the difference between these two video configuration settings?

Can video be shot at 24P in Australia, even though the video standard here is 25P? What are the disadvantages of shooting 24P video in a country with the PAL video standard? I don't mind shooting 25P but being a bit of a traditionalist and having come from film I must admit I'd like to shoot 24 fps if at all possible.

If I look up a table in the camera manual I see that if I shoot 24P video the Hz setting automatically becomes 24Hz. I don't know if this would be a problem in a 50Hz country.

Keen for any advice, and your views, on these questions.

 

Edited March 10, 2023 by Jon O'Brien

[Aapo Lettinen]

UHD / 4k is actually pretty useful for youtube videos and I think you should just calculate the higher costs to the quote by default. The client will pay the costs anyway so it differs a lot from personal projects. Hard drives are relatively cheap nowadays and the main difference will be that it may take longer to edit the higher resolution project which may affect schedules... that may matter in that kind of business where the videos need to be delivered quickly and regularly to keep the channel up and running.

1080p 50Mbps long gop was pretty fine 10 years ago but I don't see any commercial use for a format like that nowadays though it could still be usable for web videos. I used to handle a lot of C300 mk1 material shot in 1080/25p 50Mbps and it was pretty OK 8 years ago but definitely had visible compression which caused some issues every now and then.

If the material amount is a serious issue for you I would probably try to shoot the higher quality uhd/4k intra 410Mbps for anything which benefits from the higher quality like intros, product shots etc and use the 1080p as a last resort storage saving option if needing to shoot tons of material for an episode like shooting 20 hours of footage quickly reality style etc.

If you only shoot an hour or two of footage a day then using the better 4k format is a no brainer and 1080p not needed by my opinion

[Jon O'Brien]

That's interesting advice, Aapo. I've seen some rather convincing videos on YouTube lately arguing for going back to 1080 for a lot of YT content, and uploading to 4K. Other people do the opposite, too, shooting at 4K and exporting at 1080.

Actually my first plan with the C300III was to do exactly as you say. I was going to use Intra 410, CLog2 (YCC 422 10 bit). Perhaps I will do as you suggest, and shoot 4K. If there's a problem with file sizes I could just get extra external drive/s. They don't cost much. I would need to figure out how to edit in a smaller file size on Davinci Resolve, too.

Edited March 10, 2023 by Jon O'Brien

[Jon O'Brien]

What tends to be the biggest problem working with 4K material .... the storage space, or the computer speed. I've got a fairly fast little machine but it's not an uber-fast editor's/colorist's special by any means. Yes, I know ... just get in there and start on it and I will figure it all out. I'm just chicken maybe, thinking what expensive computer I might need. This is a steep learning curve, but I'm getting there.

[Nicolas POISSON]

If the video is too be viewed on a computer or phone screen, it will be mostly displayed at 60Hz wherever in the world (although some phones have a 144Hz refresh rate now). The viewer's graphic card will do the frame-rate conversion, with the inherent risk of jerky motion. Technically 30 or 60Hz would be better for shooting, but billions users watch billions videos with various frame-rate every day, and nobody hardly complains. Many web videos are shot in 24P, even corporate ones that will never reach any theatrical release, just because that is the historical movie standard. For web, choose whatever frame rate you prefer, 25P is not better than 24P in 50Hz countries.

[Jon O'Brien]

Thank you Nicolas. I wonder why people now bother shooting video at 25P in 50 Hz countries such as Australia. I'm pretty sure that television here was or still is broadcast at 25 fps but I could be wrong. I suppose that if it still is, and if the footage might be destined for television, then shoot at 25P in Australia. But, otherwise, I'd be pretty much inclined to stick with 24P if I can. I suppose there could be a couple of problems here or there, depending on shooting speed and the local Hz. Like flickering lights or screens, on the footage. But the only way to know for sure is get shooting and do some tests. What a complicated world digital video is. Film is so much simpler.