GH2 1080i vs 1080p

robbie75vr

robbie75vr

Active member
Today I had a chance to try a GH2, I film documentaries for web use, and I normally need to do pans in my productions. I noticed that 1080/24p strobes a lot when I pan and 1080/50i doesn't strobe at all so now I wonder, for web use, now that I saw this big advantage of 50i with these kind of camera movements, is there any reason why I should film 24p instead of 50i ?

(I don't need to specifically shoot 24 or 25, I just need that my images don't strobe all the time I move the camera)

Thanks
 
Once you convert it to 25p for web use it will strobe again. Only way is to use the correct shutter (1/48-50) and slow the pans right down to about 7 seconds from side to side.
 
Gh2 the camera you cant pan with:) would be very Intresting to hear what Barry says about this strobeffect in pans maybe " Well dont buy it if you dont like it"
 
not really, you can pan very well in 1080i if you watch it on TV, I did it yesterday, incredibly fluid. The problem is when you go progressive.
 
in my case it's a bit different , I do aerial videos with that camera gimbal on a gyro stabilized aerial platform but I got your point. thanks
 
robbie75vr said:
7 seconds, that is probably lens related, Imean a 300mm will require slower movements of a 28mm no?
Click to expand...
I use this chart to figure out panning speeds (it is not mine, I just reuploaded it as the one I got it from doesn´t host it anymore). It´s for real film frame rates so it applies only to 24p.
 
Shooting 24p has it's disadvantages, But overall it still looks better to me. This isn't just a video issue, 24 frames per sec. with film will strobe too, it's just the nature of the frame rate. The reason your not getting the strobing with the higher frame rates, or interlaced is because, just that, you have more frames to fill in the void. Thats why when panning slow helps, your giving the camera the time to shoot the extra frames to give it fluid motion. Like some of the above posters have said 7 seconds, sometimes more , like ten or elevin, you just have to experiment, because different lenses, at different focal lengthes will effect this as well. You can always shoot interlaced, then deinterlace for web. And keep it intlaced for tv viewing, which your tv will do it automaticaly remove pulldown. This is why people shoot with higher frame rates when slowing footage down. The extra frames smooth it out.
 
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So it looks to me that the problem is that computer monitors can't play interlaced
videos as a normal TV does, right?

The 25fps interlaced in normal tv are incredibly smooth even if you pan very fast,
I'm doing it now as I talk on my tv, but as rambooc1 said, when I convert it to
progressive for computer playback it strobes again. At 50p it just strobes half
but it always strobes... (on a pc monitor).

So maybe the perfect workflow for productions that goes both on TV and web is
to shoot interlaced, make DVDs for TV and deinterlaced them for web.. in this way
I'm having better results on normal TV so far...

For what I understood from my experiments, the difference is not from 24 to 25,
but from interlaced on tv to progressive on PC.

You see strobing also in Hollywood movies at the theaters especially if they pan on
a focused landscape with high contrast vertical lines such as trees or walls... it's just
that they generally don't pan in those situations and if they do it they keep your
attention on something else, like a person walking in the center of the video so that
you don't notice the strobing. That's what I noticed.

Different story for TV documentaries captured as interlaced and not with film or
progressive cameras, no strobing at all (on TV), and it's not the extra frame of 25 PAL
fps versus 24fps, it's the interlaced thing.

I have a camera here now plugged to my TV, interlaced pans very good, progressive
doesn't, same camera, same framerate, same subject, same pan speed.

I think that in the GH2 is more visible because it creates a sharper picture of an older
camera, so the contrast of the dark/bright edges of vertical lines is stronger, and this
makes the strobing more visible, again I could be totally wrong but this is my impression.

Let me know what you think..
 
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Thanks Barry,
you confirm my observations.

In my case it's not a matter of like it or not buy it or not,
I belive it's a matter of use the tools in the correct way,
that's why forum exists.. to share knowledge..
 
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Correct Robbie
For smooth results either use 720p 50/60 fps or shoot/edit/render interlaced and let the PS3/media player or TV blend/de-interlace etc. to give you smooth pans, if you de-interlace before you render you will end up with 25fps and less smooth panning.
Cheers
Paul
 
Thanks Paul, if I use a camera that has only 1080/24p 720/25p ? no solutions here I guess...
 
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