GH2 GH2 24p or weird strobe effect

paoloperelli said:
that is non sense.

In the past people had to comply with limitations but that was the standard.

These days I cannot shoot professionally having that kind of fault.. It would be nothing but true disaster.

And yes rigby, I will return my machine as the end of it. There is something weird going on the software side.

Progressive means that there are sequential photo stills, bottom line. Here I have doubles and how can that be the end of it?
Click to expand...

Today, shoot with a film film camera at shutterspeeds and panning rates out of 'bounds' that have been determined for 'smooth' motion, and you will get undesired results.

What this discussion may point out is that few 'digital' shooters have taken the limitations of motion capture by 'any media', or limitations for their particular camera and whatever DSP is associated with the data stream.

When I first considered buying the GH-1 vs. the Canon 7D, the GH-1 forum was a blaze with concern about 'mud'. However, for the most part, the 'mud' that was given in example after example, was for a 'whip pan', which
exceeded the DSP processor's ability to 'deal' with it... I bought the GH-1 despite this 'horrible' artifact... because... I don't have a need for a 'whip pan'. In viewing hunderds, nay thousands of movies, I don't think I'll need one
any time soon, given the lack of use of such a technique in an overwhelming number of them.

If your shooting style requires whip pans every couple of seconds, well, buy a camera that performs. If not, then in some sense you have spent a fair amount of money on a feature that has no use to your work.

For film it seems there is a 'rule' about how fast an object may 'travel' across the full length of the screen. It seems to be about 5 seconds, given my recent look on the web, since I don't have access to the ASC manual, and the tables
that are listed for such things. It could very well be that for 'digital cameras' in the class of the GH-1/2, 7 seconds, or 10 seconds may be the 'required' speed for minimizing any artifacts that the camera and processing may entail.

That is what a 'professional' does, find the limitations of the device or medium and work with in those. Additionally there may be some postprocessing tools that can assist in minimizing some set of artifacts.

If your customers sit with their displays, stepping through frames, analyzing each still for any artifact they can find... whether it is truly objectionable or not, and I'll claim that the 'ghosting' effect that is seen in the examples, is an inconsequential artifact for almost all situations, unless you are performing some sort of forensic work... then by all means pay the price for a camera that can provide a much higher data rate, with fewer such artifacts.

In most things it is easy to find something to complain about. And given the 'newness' of digital video at this price point, there are many things one could complain about if one sat down and stepped through frames.

As I've said before, the biggest things I'd like to see improved are bit depth for intensity, and higher color sampling... But I'm willing to work with what is, and perhaps in a year or up update as technology marches on.
 
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j1clark@ucsd.edu said:
Today, shoot with a film film camera at shutterspeeds and panning rates out of 'bounds' that have been determined for 'smooth' motion, and you will get undesired results.

What this discussion may point out is that few 'digital' shooters have taken the limitations of motion capture by 'any media', or limitations for their particular camera and whatever DSP is associated with the data stream.

When I first considered buying the GH-1 vs. the Canon 7D, the GH-1 forum was a blaze with concern about 'mud'. However, for the most part, the 'mud' that was given in example after example, was for a 'whip pan', which
exceeded the DSP processor's ability to 'deal' with it... I bought the GH-1 despite this 'horrible' artifact... because... I don't have a need for a 'whip pan'. In viewing hunderds, nay thousands of movies, I don't think I'll need one
any time soon, given the lack of use of such a technique in an overwhelming number of them.

If your shooting style requires whip pans every couple of seconds, well, buy a camera that performs. If not, then in some sense you have spent a fair amount of money on a feature that has no use to your work.

For film it seems there is a 'rule' about how fast an object may 'travel' across the full length of the screen. It seems to be about 5 seconds, given my recent look on the web, since I don't have access to the ASC manual, and the tables
that are listed for such things. It could very well be that for 'digital cameras' in the class of the GH-1/2, 7 seconds, or 10 seconds may be the 'required' speed for minimizing any artifacts that the camera and processing may entail.

That is what a 'professional' does, find the limitations of the device or medium and work with in those. Additionally there may be some postprocessing tools that can assist in minimizing some set of artifacts.

If your customers sit with their displays, stepping through frames, analyzing each still for any artifact they can find... whether it is truly objectionable or not, and I'll claim that the 'ghosting' effect that is seen in the examples, is an inconsequential artifact for almost all situations, unless you are performing some sort of forensic work... then by all means pay the price for a camera that can provide a much higher data rate, with fewer such artifacts.

In most things it is easy to find something to complain about. And given the 'newness' of digital video at this price point, there are many things one could complain about if one sat down and stepped through frames.

As I've said before, the biggest things I'd like to see improved are bit depth for intensity, and higher color sampling... But I'm willing to work with what is, and perhaps in a year or up update as technology marches on.
Click to expand...

I really like this post, it makes me think about how I need to really evaluate my shooting technique and adjust so my content is shown the way I want but within bounds of what the technology will allow in a visually pleasing way. I agree, I have no need for whip pans unless I used a FCP transition as such, otherwise planning my shots is my M.O. for most work so some shots will just require a little ,ore attention to detail to maximize the benefit of using the GH2. Not a bad thing to plan better and work smarter.
 
Have not really followed this whole thread but here is some more strobing footage. Play this back full screen in order to see it.

shot @ 1/50 sec. 24p.

 
j1clark's points are well made, but are somewhat beside the original point ..... there's clearly something badly wrong with how Paoloperelli's footage is showing up with "doubling" in his fast pans. Whether or not it's bad technique, there's no way 24P should ever end up looking like that. Whether its a hardware issue (which I doubt) or software (likely) we still need to get to the bottom of it.

Another thread I skimmed by recently mentioned there was a bug in CS5 whereby progressive footage from the AF100 was treated as interlaced by default. I have CS5 myself and havent run into that problem with my GH2, but that might be a clue to what's happening to some folks' footage?
 
bitcrusher said:
Have not really followed this whole thread but here is some more strobing footage. Play this back full screen in order to see it.

shot @ 1/50 sec. 24p.

Click to expand...

There is a video about strobing with the new nikon 7000, wheras one comment says it would be normal with 24p... I saw similar things but also slow pulsating with my gh2 but need to test this again (the pulsating was almost not noticeable on my bigger TV, but I see it on the smaller TV (60hz is the only option)...maybe it was an issue with the tripod. Will do the same with trees and look if its similar to the thread starters problem. I didnt notice this with very slow pannings doing tests outside in nature. All I watched so far was directly from my gh2 with hdmi cable to my TV screen. But like some mention in this thread and in the comments about the D7000, it seems this could be normal for 24p. (Iam a beginner so dont have the knowledge to judge)

Strobing with D7000 in 24p and long comment on it
http://vimeo.com/19384439

7d and strobing
http://www.vimeo.com/15906354

edit:

I did a new test with just my desk and had almost similar results like in this video with the AF100, maybe slightly less. But I had also some kind of pulsing every second, which is not seen on the vimeo video.

AF100
http://vimeo.com/20450543

I did watch this video and the result of my GH2 (with HDMI cable) on my 60hz sony Bravia 720p HD TV....

Now i changed the TV and watched the results of my GH2 (with HDMI cable) and did notice a difference, without the pulsing and very slightly strobing. This TV is full HD 1080p and supports also 24hz up to 100hz, donno what the TV did choose for my out of cam video.

Maybe its also a Monitor/TV issue aswell... ?

(I own the PAL GH2)


edit2:

I did plugin the 1080p TV (Pal) on my pc with 24hz, the videos shown on vimeo are not much different. Strobing is still visible from the panning (Wilsey video), the D7000 and also the AF100 video.
 
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i'm sorry, but all i can see is the same 24p strobe on all those samples, worsen by monitor refresh rate & contrasty background.
the strobing on the Canons is so similar to the GH2, that i also cannot tell the differences between various 'softer' implemented 24p and the GH2 native 24p.
at the moment, the only two clips that may show a different problem, might be the Paoloperelli footage and the original footage that started this thread,
so those two should be exactly mimicked with another camera for final verdics.
 
I own a GH2 and it strobes in both modes, 24p and 50i. Even the 720 50p mode is not perfectly smooth, as there is some very subtle flicker noticeable. But I really have to concentrate my attention to it, in order to see it...
I agree with those users, who say, that this is just the nature of the thing. I haven´t seen any GH2 footage, without clearly visible strobing during pans or faster moving objects in front of a bright background.

If there are some examples of a perfectly smooth movement, shot with a GH2 (or even 5D, or any DSLR) in 24p or 50i mode, please surprise me. :smile:
 
From all the footage I have seen the issue is either shutter based or software based... a shutter of 50 outdoors should give a motion blur trail - not a double image... a double image is something wrong along the processing chain - it could be anything from how your NLE is handling 23.976 and how you are rendering it out.. wrong settings and the software will do weird things to the footage and not give you frame x frame accurancy. All these things must be examined. Indoors, shooting at 24p, you can get away with a shutter of 30 or 40 and you may like this or not like this depending on taste as it ads even more motion blur trail and give you some more light esp with the slow kit lens.
It should NEVER look like a double edge. As your shutter increases, the picture gets the 'strobey' look because of a lack of motion blur. motion blur is part of the film look and it is the trail produced when the shutter is open for only 1/48th of a second on a film camera to capture the light... something moving very fast will have motion in that 1/48th of a second, thereby leaving a trail... the trail is the LOOK of film. Video at 60i or 60p has very little trail even though the shutter is ony a little faster - it makes a huge difference because all the frames are shown - so 60p with a shutter of 60 looks 'live' but 24p with a shutter of 60 is fairly close to a 1/48 shutter although I prefer 50 if possible (outdoors or you test it and get to problems from 60hz lights) even video at 60p with a shutter of 1000 in bright daylight will look strobe like because it is capturing almost NO motion trail whatsoever because it is in theory only exposing the sensor to light for 1/1000th of a second.

The question here is - does the GH2 have a bug where even though you are in manual mode - set to 24p cinema, with a shutter of 50, that is it changing the shutter on it's own?

In the auto mode, the camera will definitely use the shutter as a means to control exposure. In full manual mode it should not. Also we must remember this is an electronic shutter, not a mechanical one, so in theory there could be something weir with the GH2s implementation of it but I doubt it.

From the day I have played with it I do not think so. These shots look like user error in either settings or rendering along the many steps from original recording on the GH2 to what is viewed on vimeo. I'll have to download the raw files again to see.... but I may have access to a relatively new GH2 this weekend and I'll confirm this once and for all.
 
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Blackout said:
From all the footage I have seen the issue is either shutter based or software based... a shutter of 50 outdoors should give a motion blur trail - not a double image...

Yes! Look at the righthand image in Post 91 for an example (shot with the GH2).

> a double image is something wrong along the processing chain ... It should NEVER look like a double edge.

Yes again - this is where the folks saying "it's the nature of 24P" aren't helping - there clearly is a real problem with the footage on some systems (I'm just not convinced that the problem is with the camera).
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to rigby

have you got your camera back from servicing yet? mine has, and they found nothing bacause all parameters were correct.
I insisted this must be a software related issue but they confirmed there is no firmware update to date.
So this is leaving me no choice but to write to Panasonic directly as I strongly feel this camera is unsuitable for pro work.
I must say I would be quite puzzled in regards to the AF100 too.

let me know,
thanks
 
Well it seems some people are just discovering what 24 frames per second actually is. It's NOT smooth motion, it is SUPPOSED to strobe. It's the way of cinema (well, currently).

Try 25p, if it's not good enough, go back to 30/50/60. Also few monitors can show 24p, thus it strobes even more. And you can't compare with your old GH1 footage unless you had a correct pulldown workflow.

edit: There might very well be an issue going on, but just sayin', as always there's a lot of screaming & yielding when someone discovers an "issue", do legit comparisons with your other 24p capable cameras & let others look at the raw files before returning your camera.
 
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I've seen it too and it's definitely not "just 24p". That's just a cop-out statement.

It's a strangeness that can't be described to those who have not seen it. It's especially bad coming from the HDMI port during live view though. Panning through a static scene at a certain rate can create the issue. If there is movement in the scene then it's not as bad for some reason.

It's like the frame drags a bit then snaps, drags and snaps, etc as you pan.
 
The main thing is that 24p looks "strobey" compared to the GH13 in 24p mode. Those of use who have been using the GH13 with 24p ticked, or with quality pulldown, may see a difference in the cadence. I see it, I saw it right off. Now, WHY it is there, I have no idea. I first assumed it was the oversharpening plus the new codec. Now I lean towards a "look" in the software.
Also, there is that curious reference in the manual defining 24p as "Record motion pictures with afterimages [sic] like a cinema"
If you want smooth 24p, GH13 with Blackout-Powell patch. It is super smooth.
 
DrDave said:
The main thing is that 24p looks "strobey" compared to the GH13 in 24p mode. Those of use who have been using the GH13 with 24p ticked, or with quality pulldown, may see a difference in the cadence. I see it, I saw it right off. Now, WHY it is there, I have no idea. I first assumed it was the oversharpening plus the new codec. Now I lean towards a "look" in the software.
Also, there is that curious reference in the manual defining 24p as "Record motion pictures with afterimages [sic] like a cinema"
If you want smooth 24p, GH13 with Blackout-Powell patch. It is super smooth.
Click to expand...

I think you already saw it, but I do not agree to this statement. My GH2's motion cadence is EXACTLY equal to the GH13. We tend to always think that what we have used in the past was "bette" for some reason. It's a natural thing (has to do with our brain always forgetting the negative parts), but not true. See my comnparison here:

http://www.vimeo.com/22334960
 
It's a strangeness that can't be described to those who have not seen it. It's especially bad coming from the HDMI port during live view though. Panning through a static scene at a certain rate can create the issue. If there is movement in the scene then it's not as bad for some reason.
Click to expand...

I see this regularly on my GH13 with playback from camera over HDMI (25p), to a 24" monitor I have. Once transferred and edited it plays back like regular progressive footage, with none of this juddering. I presumed that this is just a monitoring problem and nothing to do with the camera itself.
 
Hmm, as soon as I saw the first video it reminded me of a high-detail Blu-ray. I was trying to think of what movie I could quickly pull up that would have a pan in it and I remembered the intro to Volver. I watched it and it was not "present" when it was just the actors onscreen (soft detail/contrast) but it kicked in with the bold red and black on screen titles. Looked at a few scenes of Moon as well, and could spot it there too on occasion. So it seems to me that detail and contrast may be the main factors, as that clip with the trees has pretty awesome detail to it. Also, in the AF-100 thread, someone commented that they did not see strobing until they moved from SD (DVX100) to HD (HPX500), which is a $10,000+ camera.

Whether the look you achieve is acceptable to you or not is of course subjective, and I can't say whether your camera is defective or not, but it seems to me a GH2 with a very sharp lens might just be too sharp and detailed to be palatable to some people.
 
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