I've been working with DVX100A a few months and there's only one thing I cannot understand. My DVX is PAL version and in 24p when I move camera to left or right (anykind of horizontal movement) vertical lines start jumping. It's hard to explain because I do not know if there's a term for this but it's as if the frame rate is too small. Let me see if I can explain it a little better. Let's say I'm shooting a black line on a white paper. I'll move the camera to one side so that the line will start on the right side and it'll go to the left side during the shot. So I have a black vertical line on the right in my viewfinder. I start moving the camera and the line starts going on the left side and then I dont see a normal black line but something flickering and it really bothers me. In 50i it's ok, the moving is smooth. I tried different shutter speeds but it's still there more or less. If anybody has any idea why is this please, explain it to me.
Is there something wrong or am I crazy?
- Thread starter marin
- Start date
scharky
Veteran
Re: Is there something wrong or am I crazy?
Do I dare start this debate?
First it is important to understand that you are shooting in 25P not 24P because you are a PAL user. 25p and 60i are your only options. Now, to answer your answer in short, you are seeing the black line "jitter" or "stutter" because progressive video is temporally (thanks Barry) less resolution than interlaced, in your case, 50i. 50 interlaced fields are shown per second in normal PAL video, but with progressive you are only getting 25 frames per second. This causes stuttery movement because there is less "time" information in your composition. The same holds true to shooting film, because you are also using 24 or 25 fps. If you move the camera too fast, or you don't redirect the viewers eye then people will notice the stuttering. Don't worry your not crazy, lots of people have noticed this, but you need to remember that when shooting in progressive scan that you need to treat the camera like a film camera, not a video camera.
Do I dare start this debate?
First it is important to understand that you are shooting in 25P not 24P because you are a PAL user. 25p and 60i are your only options. Now, to answer your answer in short, you are seeing the black line "jitter" or "stutter" because progressive video is temporally (thanks Barry) less resolution than interlaced, in your case, 50i. 50 interlaced fields are shown per second in normal PAL video, but with progressive you are only getting 25 frames per second. This causes stuttery movement because there is less "time" information in your composition. The same holds true to shooting film, because you are also using 24 or 25 fps. If you move the camera too fast, or you don't redirect the viewers eye then people will notice the stuttering. Don't worry your not crazy, lots of people have noticed this, but you need to remember that when shooting in progressive scan that you need to treat the camera like a film camera, not a video camera.
Z
Zoomforce
Guest
Re: Is there something wrong or am I crazy?
Good point Scharky.. I think that what he may be seeing as well is the fact that the viewfinder on the DVX only displays at about 18fps, its not realtime, do mostly to the fact the processing power is more focused towards the whole progressive capture process. You should notice an improvement when you play back the video after its captured on a computer, playing back of course at realtime. (no fx)
Good point Scharky.. I think that what he may be seeing as well is the fact that the viewfinder on the DVX only displays at about 18fps, its not realtime, do mostly to the fact the processing power is more focused towards the whole progressive capture process. You should notice an improvement when you play back the video after its captured on a computer, playing back of course at realtime. (no fx)
alpi69
Veteran
Re: Is there something wrong or am I crazy?
first of all: PAL plays 50i or 25p. 24p and 25p are basically the same for a human eye.
the stuttering is a "problem" indeed. many say it is just like in film, but that is not at all true because somehow the image is still sharper than on film and therefore the stutter is more visible (or more disturbing looking) than in 16mm or 35mm. it held me from buying this cam for 3 months, but finally i ordered it. there are to many ups for this only down, which can be dealt with in most situations. i simply can´t use the 25p for run-gun shots, but use it only for commercials and filmshots where every shot is planned and controlled.
the top 9 solutions to avoid the stutter/strobing/jerky pans i collected in many forumhours here and in other forums:
1. avoid sharp vertical edges; set shot up different if possible
2. pan slower
3. lower detail level in menu
4. only use thick-mode when outputting to TV
5. add an object in the front of the picture to get point viewer´s attention there instead of the background
6. "roll camera over axis": what i mean is this: it helps to have the cam on a dolly and when you pan from right to left you simultaniously move the cam from left to right. this is a trick many big productions seem to use.
7. try to lower the DOF area to get a blur in the background
8. lower shutterspeed to 1/36th (but this increases DOF again...)
9. worst case scenario: use 50i and adapt shot in postproduction (i use filmFX2.2 in speedrazor and also use digital fusion sometimes)
it also seems interesting that on a newer good TV the strobing is less viewable than on an old TV with less resolution. at least it seems to me. we have an old production TV in the studio as 2nd reference, cos we always try to produce for the least equipped viewer (like in webdesign, when you have to programme for the dumbest user thinkable). if it looks good on that screen it will look awesome on anything higher. we only had great experiences with this mode of production. also keep in mind that even when the stuff looks great on a studio monitor it will be degraded by broadcasting.
so basically, your cam is ok. panasonic might find some solution in the next years to soften the edges. and it seems in 25p the effect is bigger, or maybe NTSC users are blinded by the fps-difference already and feel it ok, while for us the fps are the same and therefore anything that looks different must be wrong.
if there are more solutions....here is the place to put them
first of all: PAL plays 50i or 25p. 24p and 25p are basically the same for a human eye.
the stuttering is a "problem" indeed. many say it is just like in film, but that is not at all true because somehow the image is still sharper than on film and therefore the stutter is more visible (or more disturbing looking) than in 16mm or 35mm. it held me from buying this cam for 3 months, but finally i ordered it. there are to many ups for this only down, which can be dealt with in most situations. i simply can´t use the 25p for run-gun shots, but use it only for commercials and filmshots where every shot is planned and controlled.
the top 9 solutions to avoid the stutter/strobing/jerky pans i collected in many forumhours here and in other forums:
1. avoid sharp vertical edges; set shot up different if possible
2. pan slower
3. lower detail level in menu
4. only use thick-mode when outputting to TV
5. add an object in the front of the picture to get point viewer´s attention there instead of the background
6. "roll camera over axis": what i mean is this: it helps to have the cam on a dolly and when you pan from right to left you simultaniously move the cam from left to right. this is a trick many big productions seem to use.
7. try to lower the DOF area to get a blur in the background
8. lower shutterspeed to 1/36th (but this increases DOF again...)
9. worst case scenario: use 50i and adapt shot in postproduction (i use filmFX2.2 in speedrazor and also use digital fusion sometimes)
it also seems interesting that on a newer good TV the strobing is less viewable than on an old TV with less resolution. at least it seems to me. we have an old production TV in the studio as 2nd reference, cos we always try to produce for the least equipped viewer (like in webdesign, when you have to programme for the dumbest user thinkable). if it looks good on that screen it will look awesome on anything higher. we only had great experiences with this mode of production. also keep in mind that even when the stuff looks great on a studio monitor it will be degraded by broadcasting.
so basically, your cam is ok. panasonic might find some solution in the next years to soften the edges. and it seems in 25p the effect is bigger, or maybe NTSC users are blinded by the fps-difference already and feel it ok, while for us the fps are the same and therefore anything that looks different must be wrong.
if there are more solutions....here is the place to put them
scharky
Veteran
Re: Is there something wrong or am I crazy?
It is true, the camera does stobe, but so do many hollywood flicks that are on DVD. You don't notice it because the have used steps like alpi's list to avoid those situations, yet, still they exist. I personally don't have a problem with it, and will even shoot 24p in run and gun situations. I don't think it has anything to do with 25p bein half of 50i, because the stobing will be noticeable even when shooting in 30p (for us NTSC) users. I have shot many 16mm short films as well, and always used these same techniques with that camera. Again, you just have to learn to use the camera like a film camera. If you follow the film "rules" you will be fine. YOu think that stobing is bad with this camera, try 8mm running at 18fps, then come back and look at the dvx footage, it will be as smooth as glass.
It is true, the camera does stobe, but so do many hollywood flicks that are on DVD. You don't notice it because the have used steps like alpi's list to avoid those situations, yet, still they exist. I personally don't have a problem with it, and will even shoot 24p in run and gun situations. I don't think it has anything to do with 25p bein half of 50i, because the stobing will be noticeable even when shooting in 30p (for us NTSC) users. I have shot many 16mm short films as well, and always used these same techniques with that camera. Again, you just have to learn to use the camera like a film camera. If you follow the film "rules" you will be fine. YOu think that stobing is bad with this camera, try 8mm running at 18fps, then come back and look at the dvx footage, it will be as smooth as glass.
Mike_Donis
Veteran
Re: Is there something wrong or am I crazy?
...I think that we all over-think the image quality of the DVX...film strobes, the DVX strobes, and why? Because its all 24 (or 25) P!
Shoot good footage and it'll blow people away ;D
...I think that we all over-think the image quality of the DVX...film strobes, the DVX strobes, and why? Because its all 24 (or 25) P!
Shoot good footage and it'll blow people away ;D