GH3 720p Workflow. Struggling to choose video format!

[Shawn Storm]

I just upgraded to a GH3 from my trusty GH1 (hacked). I am struggling with the transition because I was very comfortable with the workflow on my GH1 which was shooting 720p30 MJPEG at roughly 80mbps which resulted in beautiful and crisp 720p footage. I edit and output at 720p30 because I am using a small MacBookPro 13" laptop and mostly just share my stuff on the web. Eventually I will probably want to switch to 1080p, but it just doesn't seem necessary to me at this point.

I have been reading lots of forum posts and experimenting quite a bit to figure out which video setting to use and it has been driving me crazy. It seems like most people agree that 1080p 50mbps MOV is the way to go, so I assumed I would use that setting and simply edit the footage on a 720p timeline in FCPX. I also somehow assumed that downscaling would produce a nicer quality image than shooting at 720p (based on my experience with still photos). HOWEVER, in my tests thus far this hasn't been my experience. In fact, from what I can see, recording at 720p seems to yield nicer/sharper videos. I have tried every video mode and eventually narrowed it down to three possibilities:

1> 1080p30 MOV (50mbps): As with all the 1080p modes, images seem somewhat blurry/soft to me, especially when downscaled to 720p. I can get the sharpness similar to the 720p footage by sharpening in FCPX, but this seems to decrease quality and creates some undesirable halos, etc. File size is kind of large, but not too bad.

2> 720p60 MOV (72mbps): Images seem sharp and good looking. I don't need the 60p (I prefer dealing with 30p in general) and the file sizes are ridiculous (somewhat larger than the 1080p 50mbps).

3> 720p30 MP4 (10mbps): Images are sharp and decent looking. In fact, I am kind of blown away that these 10mbps videos look as good as they do. In some of the tests I could barely tell the difference between this format and the higher bitrate ones. File sizes are very small (nearly 1/20th the size of the 720p60 MOV files).

So I am kind of at a loss. I would love to hear suggestions as to what makes sense in my situation. I also think my tests weren't extensive enough to cover all situations and I am guessing there are shooting conditions that will change my above observations?

I realize this topic has probably been discussed a fair bit, but I haven't found an answer to my specific situation and I would be very grateful for any advice.

Thanks much!
Shawn

 

[Shawn Storm]

I am still trying to figure this out and would love for someone to offer advice.

In the meantime, I have done more testing of the various formats and am still rather confused. Which codec looks best seems to change from scene to scene. In general I have been somewhat impressed by the MP4 720p30 (10mbps) which really confuses me. It often tends to be sharp, detailed, and good dynamic range. How is it possible that one of the lowest bitrate settings seems to often look better than the much higher bitrate options? The 720p30 MOV (All-I) has also been nice on many tests, but on a few looked horrible. In general the 1080p30 MOV (IPB) seems to hold up well in most of the tests, but I am still not sure I want to be using 1080p with my 720p workflow. Also it seems much softer/blurrier than the 720p footage. In all my attempts to downsize it to 720p there is not much obvious improvement over the 720p files (from what I can tell).

A couple of questions that relate and will help me in my process:

1> How exactly does bitrate apply in quality comparisons between 1080p and 720p? I have been trying to understand this for awhile and can't seem to completely figure it out. Will a 720p30 video at 50bmps be the same visual quality as a 1080p30 video at 50mbps? Or does the increased pixel count on the 1080p affect the formula which means the 1080p footage would need to be around 100mbps to match the quality of the 720p?? I realize that quality is often a perceptual thing and the answer will vary greatly upon who is looking and what format the video is viewed on (HD Tv, high rez computer monitor, etc). So for my question, lets say we took two 50bmps videos (one at 720p and one at 1080p) and cropped (not reduced) the 1080p footage to be 720p sized, then viewed both on a basic computer monitor. Would one look better in terms of image quality?

2> If I do end up shooting with a 1080p codec, does anyone have suggestions of the best way to edit the footage with FCPX in a 720p workflow to maximum final quality? Would it make more sense to edit in a 720p timeline or a 1080p timeline (and output to 720p)? Since the 1080p footage seems soft to me, what is best method for sharpening the video?

Thanks in advance for anybody that can help me in this process,
Shawn

 

[Shawn Storm]

Here are some images that show what I am talking about. Images taken from screen shots of original files (except the 1080p footage).

This is a small preview of the full test frame:


First image from 720p30 MP4 (10mbps):


Second image from 720p60 MOV (72mbps ALL-I)


Third image from 1080p30 MOV (50mbps IPB) which I downsized and sharpened in FCPX.



From my perspective, the 10mbps MP4 (first image) looks the best in this example. It is sharp and has good detail. The 720p60 ALL-I footage (second image) looks bad to me (especially in shadow and high detail areas). The 1080p30 downsized footage (third image) looks ok, but I still like the MP4 more.

This presents a challenge because I keep liking the 10mbps MP4 footage the most. Some part of me feels it would be a mistake to start shooting everything in this format because of the low bitrate. Although it has looked great in my tests, it just doesn't make sense that it would outperform the other codecs.

I really wish the GH3 had a high bitrate 720p30 option (such as a 720p version of the 50mbps IPB). With all the options available I am confused why it doesn't. For my situation (working exclusively with 720p) it just makes sense, and I am still struggling to choose which coded to use. The frustrated part of me is thinking of giving up on the GH3 and going back to my trusty hacked GH1 which is set up to do what I want (capture high bitrate good quality footage at 720p). However, I do want to make the GH3 work (especially since my hacked GH1 won't play back the footage and it occasionally crashes due to the high bitrate, etc).

Once again, thoughts/suggestions would be appreciated.

Thanks,
Shawn