UNHAPPY *25p PAL* users: LET'S WRITE to Panasonic!

Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

[quote author=Jay_Blanchard link=board=Events;num=1077903628;start=75#79 date=03/05/04 at 06:53:23]


i'm of the opinion that those folks who aren't seeing this problem simply don't want to see it or haven't shot film before.  i have, i know what i'm seeing & i don't like it.  i'll continue to use this camera for limited applications, but besides that, it won't replace 16mm for me, not by a long shot.  

i don't know what's causing this issue--acquisition, pulldown, image stabilization, lack of resolution: it's not my job to know.  i'm not a technician, i'm a media producer.  i use my eyes for a living & i trust what they see.  and unless i was half blind with cataracts, i can see the difference between footage others and myself have shot in 16mm and that shot with the DVX. [/quote]

nothing to add - couldn´t say it better
 
Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Who said that the dvx was supposed to replace 16mm.  I too would chose 16mm over dvx footgae anyday, and I'm sure that anyone with the option of shooting 16mm would do the same.  The dvx100 is a completely different medium and needs to be treated like one.  I guarantee that any other camrea in the future that shoots 24p or 30p for that matter is going to have the same issue.  There is a great article in Video Systems magazine (february 2004 issue) that talks about every progressive cam from the JVC HD10 to the dvx100 to the more expensive sony and panasonic Varicams. All of this cameras will experience judder unless proper settings are used to compensate. There is an interesting strobe sensitivity ratio chart that is shown in the article.  I understand Jay that you don't like the look of the dvx, which is fine but I have to ask, why are you a dvx senior member?  Have you always felt this way, or just recently.
And about the movie that you saw with no strobbing whatsoever, it is true there are many movies that are crystal clear (motion wise) however, there are also many that are not.  I have seen lots of dvx footage the is jittery like a bull on steroids, but I have also seen a lot of footage that has smooth as glass pans as well.  The only way to understand this new medium is to experiement with it.  It is not film, it is video.  Therefore while some "film rules" do apply, so do "video rules" and since it is unlike any video that could be shot before, there are also some "new rules" that apply to how you can shoot video.  If you feel thes rules are too limiting then shoot 60i video or 16mm.  However, if you convert 60i video to 24p and your panning, I guarantee 100% you will see the same juttery movement.  That's just the nature of the beast.
BTW will someone please try my experiment.  I put a lot of time into that thing :)
 
Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Scharky! I would like to try your experiment....but I still don't know how to get that PC monitor jitter on video solved!....I also tried other refresh rates....nothing changes.... :-X

Sorry... :'(

I do appreciate a lot your test....I hope someone else with no PC problems can try it out....

Cris
 
Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

That is really my point, there is no way to solve it, and we are actually talkng about 2 completely unrelated things here.  FIrst, monitor tearing is enevitable.  You can't do anything about it when viewing a quicktime file or whatever.  Fast movement/action will tear on video monitors because of the refresh rate conflict.  Since you can't have a refresh rate of 24hertz or even 48 for that matter, you will always experience tearing.  Think of it in the same way that sincroscan works with monitors.  Even if you sincro scan is of by .1 you will see tearing in the monitor, or flickering.  this is the same thing.  You can however, burn those files to dvd-/+rw and viewthem on your computer DVD rom.  Somehow software engineers were able to solve this problem with dvd software.  Now for the second point.  The flickering, double immages and whatnot are a product of progressive scan.  These tests were not created by the dvx therefore support my point that the dvx is not at fault.  If you convert 60i footage to progressive scan you get the same thing.  You just have to find a way to work with it.  Most movies you will not notice the flicker when shown on progressive scan tv because there is a subject in the foreground that your eyes are trained on.  I have found many techniques that work quite well for me it not noticing jutter.  Of coarse when you really look for it, you can find it, just like I can on every single dvd that I own that is 24P.
I have one more link for you all.  This is from a documentary that I shot. it has a man moveing infront of a brick wall, with doorways and everything.  Jutter nightmare right?

http://www.stefweb.net/stress.avi
this is an uncompressed dv file so it is about 17megs, give it time.
 
Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

"stress.avi"

This is a good example of how to do it right. The bricks show substantial strobing, but you don't notice it because you're watching the guy.

The examples I mentioned in "Network" are similar types of shots, but the camera is moving much quicker and the strobing is dramatically harsher. Yet they employ the same technique, following an active subject and keeping the subject relatively stationary in the frame, to keep the viewer's eye trained on the subject and therefore to not notice the severity of the strobing going on behind them.
 
Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

[quote author=scharky link=board=Events;num=1077903628;start=75#83 date=03/05/04 at 10:35:25]Since you can't have a refresh rate of 24hertz or even 48 for that matter, you will always experience tearing.  Think of it in the same way that sincroscan works with monitors.  Even if you sincro scan is of by .1 you will see tearing in the monitor, or flickering.  this is the same thing. .[/quote]

Sorry small correction - To be fair to the DVX 100  I looked at  the PAL footage with an exact monitor refreshrate of 50,000 - you can do this with a programm called Powerstrip and a PC - its kind of tricky b.t.w.
Powerstrip is mainly used to sync a high End beamer to PCs and to playback progressive footage. We used it to exactly get the needed 50,000 Hz for Pal progressive 576 p.

- We used a program similar to yours called "Juddertest."

Concerning your movie its 30p and if i would get a motion rendering
like this in 25 p I would be a happy guy.
 
Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

actually my movie was shot 24pN. Yest it si 29.976fps but that is because pulldown was used in the rendering. IN the NTSC version there are two types of 24p. Normal and Advanced the advanced would be output at 23.98fps, the normal at 29.976. WHat you are seein in the clip is infact 24p.
 
Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Sorry to come so late to this. Seems to me a whole lot of issues have been thrown into a blender. Here's my spin on what I've read in no particular order:

1) Film xfers can yield different results re motion artifacts depending on how the telecine handles the film. Best systems do it static frame by frame but this is a slow process, others keep the film moving and do a motion compensation.
2) Film is different to 25/24p. In a film system entire frame is exposed at once, shutter angles / exposure times can make a difference. This even applies in still photography. Iris shutters give different results to roller blind shutters re motion artifacts. High end video cameras use a mechanical shutter, low end use electronic. What's the difference in real terms. Well with an electronic shutter the first scan line is read before the last, if something is moving then it's going to appear in a different position in the first scan line than the last. Because it's a scanned image it'll tear if it's moving fast enough witha slow shutter speed, you can get this to happen even shooting interlaced.
3) As has been mentioned you can also get serious strobing problems with practical lighting that isn't purpose built for video / film. Fluro lights turn on and off 100/120 times per second. This is most obvious with fast shutter speeds. I've been caught out by this shooting interlaced, no doubt it'd be much, much worse in progressive. In interlace at worst one field would capture the moment when the lights were 'out' but they'd be back 'on' in the next field. With progressive you coould get a whole frame (i.e. two fileds) where they're 'out'.
4) The acid test is to look at the footage frame by frame, if the exposure levels are constant and each frame looks OK then the cameras doing what it's meant to, if it looks crappy at full fps it ain't the cameras fault.
5) So far I've not seen anything that looks like a camera fault to me.

Every type of media brings its own pros and cons. I just read an artical on the shooting of Imax Indie 3D. Imax has a problem with artifacts on horizonatl motion as the film also moves horizontally in the gate. Big difference in the film world is they can afford to have guys on the shoot who do nothing but prevent these sorts of problems.

Standard video has many problems too, moire is one. Used to be if you turned up at the studio wearing the wrong clothes (fine stripes were a nono) you got sent to wardrobe real quick. These days no one seems to give a rats, yuck.
 
Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

After all this "motion blur alike" matter,
Is it still logical to buy a dvx100a?
Or does the pd-170 for example have an advantage over the panasonic?
 
Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

So.....after two weeks of heated debate I think ENOUGH views have now been expressed to reach SOME conclusions. I would therefore like to repose some of the quetions I had posted earlier:

Based on our discussion here in this forum so far, CAN we conclude that:  

1. The PAL version of the DVX100 family (both DVX100E and DVX100AE) are technically  'OK' cameras AND Strobing/double images are problems related to Progressive Techncology,,,NOT DVX???

2. How would u compare DVX100 with Sony PD150/170 now???(those who might have an experience of both)

3. By making use of the various options (shutter speed, Iris, gamma settings etc), and by using the camera properly (tripods, avoiding fast pans etc) we can 'effectively' control the strobbing????

4. the issues raised in this thread and the other one concerning the problems of the DVX100, are partly due to the fact that the 25P, for which this cam was a pioneer in the Mini DV category, has NOW reached at the crossroads of usage between various old and new technologies (of recording, editing and display), and users (professinals and prosumers).???? This involves a wider use than before of Professional cameras; resultant higher expectations attached with them; and less wider availability of Progressive TVs etc.

5. If there is really a PROBLEM with the camera, even after two weeks why the opinion is sooooooo divided on WHAT IT REALLY IS???

::) ??? ::) ???
 
Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Aejaz,

i think you put it right here. there are some users who are unsatisfied by the preview quality on traditional / interlace monitors. i go and watch my materials on my interlaced TV and actually think i can see what they're talking about, but i've always accepted it as normal. and that should also answer your 5th question.

another problem is that this forum is limited to the net as a medium, we eventually can not compare here 2 users with their 2 TV sets.. and them both to the Panasonic standards and just then, to ask if it's an acceptable quality or not. i could say that this debate brought this platform to it's limits and should go on and test things in real world, in a lab.. with real technical devices etc. otherwise we'll be stuck with this thread forever.    

it all gets to one's expectations and therefore i couldn't say the "unhappy users" are right or wrong. after all, they ARE the clients and they ARE right.. if looking at it this way :)

my big question mark is now: what IS a "real" progressive capture? is the 25P system of the SDX900 is different in any way from the one in the DVX100? as much as i understand, the progressive look of those two cameras should be looking same. if they're not, then i guess a redefinition is needed here.

bottom line, i'm a happy costumer who supports the legitimate struggle of our brothers PAL and NTSC unhappy users, and hope the truth will be revealed sooner than later.  
 
Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Hi,
after two weeks of debating i've learned a lot of rules and tricks TANKS A LOT.
Assuming that the camera is OK and that the defects is due to inadequate playback tools i've got already some doubt:

For me (referring to Aejaz)
1. the progressive mode to be ok would have to work like a film camera (!!i'm not comparing the quality!!):
To each frame (24 p - no shutter 1/24) is dedicated 0,04166 second. A portion of this time is stolen from the maccanical switching between two frames and the rest is dedicated to the impression of the film-emulsion.
So the frame is obtained from 0,04 sec of constant exposure. The lack for switching is what produce real strobes that is visible also in analog projection.
Do the DVX and other progressive camera use the same principle?

2. Progressive is the future.

3. all the solution purposed before helps in smooting strobes and artifacts but not to avoid it.

BUT if all is caused by the interlaced reproduction why there isn't one software or plugin that filter the progressive material for interlaced displaing?? (ok it's one step back but it should be very usefull)
 
Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Haha, so this problem is not really a problem? This is like back in the days when electricity was first introduced and ppl were all confused by them...how embarassing for the original post.
 
Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso


I'm not embarassed, actually.... I still have to figure out what we can do to get better progressive images from the DVX, as many people stated footage coming from other cameras looks just fine. ???
I have to shoot a short next month, and still I don't know if I can use progressive or not.... :-X

So please, Jay and Brendan, let me know if you can write that text, so we'll be able to write to Panasonic as soon as possible. Thanks.

Cris
 
Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

[quote author=veganway link=board=Events;num=1077903628;start=75#93 date=03/06/04 at 09:15:47]
I'm not embarassed, actually.... I still have to figure out what we can do to get better progressive images from the DVX, as many people stated footage coming from other cameras looks just fine.  ???
[/quote]

What the hell? other cams? the DVX is the only progressive prosumer camera. of coruse the others look fine 'cause you're used too them.
 
Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

ok.. heres my 2 poop cents on all this ..
its not an issue of the dvx producing the images, the issue is how your going to present them. in the case of the ntsc model. it offers the standard telecine with 24pn which uses the same all time proven telecine to ntsc, and looks beautiful on any ntsc set, or you can telecine the true 24p after doing a pulldown from 24pa and editing. so it works out nicely that theres no reall issue that prents itself to the ntsc users for displaying the 24p fottage on an NTSC set.
now, with the pal version. it seems its not quite as easy to go to your native broadcast standard to display the progressive images nicely. but its not a real camera issue, and not the cameras fault. youve got 25 perfectly fine progressive images in your nle which you can output anyway youd like. film or whatever. how you get them to play nice with a pal tv is your issue. the camera is an aquisition tool which has already done its job, just like its was supposed to and because of the method of capture your allowed to edit, and work with them on pal equipment, without buying anything additional. however, when it comes to outputting that 25p to its intended final destination, thats not the cameras job to make the progressive footage display right. when you stick that cam in 25p, its no longer a tool for getting "PAL" footage. it then starts to record 25p footage, and break it down into a pal signal, so that you dont have to buy some sort of 25p equipment. the issue the pal people should really be concerned with is "how does 25p get transferred to a pal signal normally to be smooth.. and how does the pal dvx method vary if at all?" more than anything you have to realize that the 25p (the same as the 24p derived from the ntsc 24pa after pulldown) is meant to be used in a progressive environment for display. such as its primary intent the almighty film out, or progressive dvd and monitor and such. an the fact that the cam lets you originally transfer the progressive images through an ntsc or pal signal is a bonus. and if the pal dvx does the transfer to pal any different then it should be to get smooth imagery, than you can always take your nice 25p progressive footage from your nle, and use whatever the correct method should be to convert it to pal. my guess is that the pal dvx already uses the the most viable method, but if you find a better one, than just use that instead from your 25p timeline to go out to your pal setup.
again though what really needs to be realized , is that the cam is NOT taking regular PAL footage, and making it into 25p images....., it is taking 25p footage, and chopping it into a pal signal so that you can pull it out at 25P on your nle after transfer... the cam does what its supposed to do.
 
Is shutter speed a solution ?

Is shutter speed a solution ?

Hello there,

I guess all this rattle and hum all around the Internet about the "unpannability" of the DVX PAL in 25P is a major issue these days.

I've been a happy (yes ! happy) owner of the jewel for two months now. And, although I've shot nothing yet but scoutings and tests, I'm quite impressed by its gentle picture quality, inspiring colour rendering and friendly interface.

But YES ! I've noticed this flickery-doubly-dizzy problem. How couldn't I ? Anyone with an eye would be bothered by the impression of drunkiness you get by watching one of your pans on a non-progressive PAL monitor (not to talk about its choppissimo look on the in-built LCD monitor...).

I don't know why, and, honestly, I don't give a ****. My concern is about the spectator's impression, not the technical issues (don't get me wrong, fellows : I'm a technician myself, but... well, you see what I mean, don't you ? We don't want to think about 25P when we're watching a film : we want to cry, laugh, be thrilled...)

Anyway, I've noticed a major improvement in my pans when shooting with the shutter set to 1/25. More motion blur ; less (if no) flickering. Something closer to what my eye is used to recieve when watching a 35mm film.

I guess this "solution" is not very rational — mostly instinctive — but it's worked on me. Does it make sense to you, guys ?
 
Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

[quote author=mauro link=board=Events;num=1077903628;start=75#91 date=03/06/04 at 06:26:27]
1. the progressive mode to be ok would have to work like a film camera :
To each frame (24 p - no shutter 1/24) is dedicated 0,04166 second. A portion of this time is stolen from the maccanical switching between two frames and the rest is dedicated to the impression of the film-emulsion.
So the frame is obtained from 0,04 sec of constant exposure. The lack for switching is what produce real strobes that is visible also in analog projection.
Do the DVX and other progressive camera use the same principle?
[/quote]
Yes, that's exactly how the DVX works (and the only other progressive camera, the SDX900). The CCD captures one image every 25th of a second. The shutter is normally set to 1/50th, so 25 times per second the camera exposes the CCD for 1/50th of a second. The method and timing of capture are done exactly as a film camera.

2. Progressive is the future.
Click to expand...
Maybe. If the ATSC HDTV standard is any indication, progressive is part of the future, but interlaced unfortunately is still a significant part as well.

3. all the solution purposed before helps in smooting strobes and artifacts but not to avoid it.
Click to expand...
You cannot avoid strobing entirely, because it's inherent in the concept of capturing footage only half the time! In regular interlaced video, you are capturing footage 100% of the time: you expose one field for 1/50th of a second, and the next 1/50th of a second you are exposing the other field. Always, always the camera is recording.

But in 25P, the camera is actually "blind" for 50% of the time! Using a 1/50th shutter, you expose 25 frames per second at 1/50th of a second each. THAT'S WHY IT STROBES. Think about it -- it's the exact same thing a "strobelight" does: it lets you see only part of the time.

But that's also exactly how film works. And it's why the DVX, at 25P, renders motion exactly the same way film does when film is shot at 25P. It's normal. It's the right way to do it.

You can minimize or even eliminate all strobing, by shooting at a 1/25 shutter. At that point you will be exposing approximately 100% of the time, instead of just 50% of the time. However, your resulting video will look very "smeary" with motion blur.
 
Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

I may be wrong here, but it seems to me that, even with a shutter set on 1/50, the encoding of the photograms (should I say "videograms") in the digital language makes a major difference with what we get with chemical films.
On an analog film, our eye sees light for 1/48th of a second, then nothing for another 1/48th of a second, then another frame for 1/48th of a second, etc.
In digital (when not transferred onto film), our eye sees light constantly. Unless I'm wrong, there's no 1/50th of a second of darkness.
Is it a stupid conclusion I made ?
 
Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

Re: UNHAPPY *25p PAL* users: LET'S WRITE to Panaso

So now that I've taken the habit to say stupid things, let's go all the way down to the realm of ridicule, baby !
What if, through some sort of technological process, we succeeded to have 50i going like this : 1/50th of a second of light, 1/50th of a second of darkness ?
Would our eye (and our brain) believe it's watching real old-school cinema à l'ancienne ?
 
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