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View Full Version : what kind of scene/motion is too much for 720p60?



Nicholas Natteau
07-03-2010, 02:02 PM
After having updated my GH1 with the firmware hack and made a number of tests, I found that shooting in 720p60 caused my GH1 to always stop filming after 6 or 7 seconds when it comes to shooting a fire.

Although I was using a SanDisk Class 10 32MB card, I had also selected the "D setting" in the firmware hack which may have been too much in 720P60 mode.

So for filming something complex like fire, I'll play it safe by using for Mbit rate:
VBA: 38,000,000
OBA: 40,000,000
LBA: 42,000,000

But what should we avoid shooting at 720p60? Or is it ok to shoot complex motion like water and fire at 720p60 so long as the bit rate isn't too high?

MR Fanny
07-04-2010, 02:36 AM
my question here is do you see a noticeable difference from "C" compared to "D"? is that extra whatever percievable IQ you get out of "D" really worth the headache compared to "C".

if it were me I'd just drop the bitrate to something stable. you can always set your H and L to lower bitrates like 32 and 22 and problem solved....no need to swap firmware back and forth.

Zissou
07-04-2010, 02:43 AM
would be best to just try it out; light a fire and film it, all different bitrates and settings you can, and jostle the fire while you are at it; try and really stress the codec. or with water. and be sure to post the results or link them; i follow the GH13 threads with enthusiasm, id be delighted to see some real concrete limits.

dmoreno
07-04-2010, 07:36 PM
I spent this weekend trying different settings for the hack to see what would work for me. I am not using the 24N option, but 24 inside 60i. For some reason FHD can stand much higher bitrates without making the camera stop. In my case, since I am using Class 6 Cards, I have been using settings of 40, 44, 50 (something in the middle of B and C settings).
My GH1 works perfectly on FHD (wasn't able to make it failed no matter how much detail, green, zooming like crazy and panning fast I tried). But fails easily on SH.
I tried with several H and L settings to try to find a stable 720 option and had to go as low as 18 mbps to get a robust setting that I wasn't able to brake.
At 22 mbps it would work 99% of the time, but I was able to make it stop by zooming in and out fast with the kit lens.
It's weird that it can handle 1080@24p (FHD) at 40 mbps but fails with 720@60p at 22 mbps.
I finally settled with FHD/SH at 40, 44, 50 (couldn't find any mud). H at 22 (which will be my choice for 720 as it rarely fails and is pratically mud free) and L at 18 (which I will use in case H fails).
For people with Class 10 Cards probably the C settings and H at 32 and L at 22 could be good stable settings.

Nicholas Natteau
07-05-2010, 08:11 AM
Thanks everyone for your feedback.

Just wanted to know what you all use to measure the bit rate?

I'm using Media Info but not sure if it's accurate. Because yesterday I was filming rippling water at a lake and got bit rates of 110-120 Mbits per second. Is that even possible? Or is Media Info reading it wrong?