GF2 Stable Settings

pvdog

No I don't know how to or where to learn how to shoot 1/50 in a sunny day without a ND filter. Let's put it this way: even if the shutter is indeed locked to 1/50 but mostly aperture is 22, do you really want it?

@Keith: I knew that, see my initial post. I assumed all my talks so far is based on without a ND filter. If Rambo has been using a ND filter, then he and I were talking two different things.

My whole point is: if you set flicker reduction to 1/50 or 1/60 and the day is too bright, GF2 will unlock the shutter automatically and immediately and use whatever shutter speed it thinks it should use to achieve a proper exposure.

Rambo

Pvdog, i agree with you that the camera appears to unlock the shutter at a trigger point. If you read above post by kavadni, kavadni 11:08AM @rambo.. """""my observation with Minolta manual lens is: Shutter stays locked Changing ISO had no effect on exposure'. The ISO appears to stay locked from f2.8 to f8 .. at both f11 and f22 the ISO changes .. it's attempting to give me the f8 exposure .. I think""

It's probably the shutter that is changing at f8 and then again at f22, but that is a large aperture range f2.8>f8 in which to use a ND or variND and have manual control. Who shoots video at f8> f22 not many people?.

I'm still running some test to see what is really happening here and post the results.

What i can tell you at this stage in M mode, if you set aperture, on a manual lens and then change shutter red from 1/50 to 1/120 the expected exposure change happens in video footage consistent with a doubling of the shutter speed. Try it.

R

kavadni

@pvdog and @rambo 'It's probably the shutter that is changing at f8 and then again at f22, but that is a large aperture range f2.8>f8 in which to use a ND or variND and have manual control. Who shoots video at f8, not many people?.'

I actually thought perhaps ISO was changing .. at f16 rather than shutter speed .. I haven't looked that close @pvdog .. Film some fast motion or some flourescent to see if it's shutter that's being adjusted

pvdog

Back to topic: I have got stable 70M GOP 3 1080 30 fps. I-B-B-I, average iframe size 656,578. Passed stress test for 13 min with the 4 images posted in this thread, spanning at 4 GB. Need a sunny day to test more on stability.

hi1130

@pvdog can you attach the ini/zip file?

pvdog

I need more tests before I feel comfortable to release the ini. But so far very promising, file size varies from 45M to over 90M, can still be played in camera, no crash yet. If a card is too slow (class-4), it'll post an error message but no crash.

holmes6

I was just messing around with manual lens @f1.4 and flicker red (1/50, 1/60, 1/120, etc) outside in bright sun.. All the settings returned blown out overexposed images.

Switched to the kit 14-42 Panasonic, Aperture mode, wide open @f3.5 14mm 1/120 flicker red set.. start video capture and can see the aperture close down (if i turn the camera around and look in the lens) until the video is properly exposed.

So how do we dupe the "fake" shutter speed unlock? (edit: read above about adjusting manual aperture, will try this)

nereo

@rambo In P mode, shutter 1/50 locked, with manual lens for manual aperture, you can modify the ISO/GAIN in video mode: before shooting push the wheel button on the right, the exposure indicator became yellow. Now you can change the exposition. The gf2, when you start rec, begin to compensate the ISO, but not completly. If you use all the regulation range you can appreciate well ...

Rambo

Nereo, holmes6, I created a specific thread for discussion on this, can you use that thread please. http://www.personal-view.com/talks/discussion/2628/gf2-flicker-reduction-behavior#Item_2

rovert

@stonebat I'm new to this hacking of my GF2. It was nice to see that we have a chance at getting better quality video than stock. Your AVCHD settings in post #2, did you compare it to stock? Is this 32Mbps a lot better than stock 17Mbps @ 720p?

I guess the time-lapse function you added can't be as smooth as using a GH because we cannot set our shutter speed to 1/2 second?

stoney

Frankly I used only 1080 mode in GF2. At least 720p mode didn't crash.

About the 1/2 shutter speed, that's a good point. Let's talk about it again when PTool supports full manual control.

rovert

OK...understood. How did using stock 1080i compared to your hacked double bitrate 1080i? :)

I must be a little confused. I use 720 because if the bitrate is the same as 1080, 720 should be sharper and contain more information per pixel than 1080? I just shoot slow panning shots and interviewing people so I was thinking 720p was better for that panning motion. Does it take MUCH MORE fast movement to make 1080i look wobbly? Maybe this new hack that you're using makes 1080i just as stable as 720p? I use Final Cut Pro to edit the files after.

Rambo

In 720 mode 50% of the bitrate is wasted on the duplicate frames which get discarded when you render the final video. So in fact you are better off shooting 1080i and deinterlacing. 720 mode is not real 50/60 frames, each frame is a duplicate. Yes there is a noticeable image quality difference between hacked and unhacked, the hacked version has more detail in less exposed areas and subjects in motion.

JayB38

So, the 1080 is key in AVCHD mode in terms of detail than in the 720p? Interesting.

KeithLommel

@JayB38: Yes, on GF2, 1080 is always preferable to 720. The primary advantage of 720 on other cameras is that it is 50 or 60 progressive frames, but GF2 sensor readout is only 25 or 30 fps, so 720 mode just doubles frames. You therefore might as well shoot in 1080 (which is 25p/30p in an interlaced wrapper) and get the extra resolution.

rovert

Awesome thank you for this explanation of GF2 720p30 vs 1080i60. You guys who know all the in-depth video settings and hacks are the perfect answer to my question. I noticed in my stock 720p footage that any quick jarring caused a wobble effect. Rolling shutter function of FCP X didn't help that. But if this hacked bitrate can give me more detail in more dynamic ranges then I guess that's all I can be happy for the video capabilities of this camera. Looks like a Canon 60D or equivalent is in order for the future of my video career!

Does Final Cut Pro X automatically change 1080i60 to 1080p30 or is there a setting to do that? I also always use a Mac program called ClipWrapper to make my stand alone MTS files into MOV for Final Cut Pro X to import.

JayB38

@KeithLommel I most certainly keep in mind on that --

holmes6

In compressed video, 2 duplicate frames typically wouldn't use 2x the bitrate.. Streamparser should provide evidence either way.

pvdog

I believe I've found the best patch and it is absolutely 100% stable:

http://www.personal-view.com/talks/discussion/2681/gf2-so-far-the-best-and-100-stable-patch#Item_1

gameb

Did anybody understand the ETC issue on the GF2? When I press recording, ETC only works in the 720p modus, which is not the one you want to use. When I am in 1080 and use ETC modus, it shows the cropped image in the LCD, but it disappears as soon as I press record and jumps back into normal mode. Means, we cannot use ETC in 1080? So why does it show it to me on the LCD in the first place, before recording? I use Driftwoods Cluster V1.

Rambo

Gameb, the camera assumes you are going to take a photo till you press the movie button.

Tomaso

@holmes6 Look at StreamParse output fr.o.m. GF3, can you see evidence for Doubled frames? http://www.personal-view.com/talks/discussion/comment/50425#Comment_50425 I do not see anything that could tell.

gameb

@rambo I understand, that means no ETC mode with 1080?

Rambo

Yep, no ETC in 1080i on the Gf2, I believe it's to do with the progressively read sensor being recorded as interlaced, was posted on ths forum or dvxinfo some time ago. ETC works in mjpeg mode same as 720p.

gameb

@rambo Cheers

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