25p on PAL TV
 

Dear all,

I'd read a lot of discussions on shooting progressive and then get unsmooth pictures on interlace tv. Ok, if I don't intend to transfer to film, and my target output is only miniDV, VCD or DVD; then, would you recommend me to shoot 25p (assuming displaying on normal home use PAL TV) to get a good filmlook video?

I want to make myself clear to whether spend lot of money on DVX100A or just get a cheaper PD170/VX2100.

Thanks!

25P output via AV and S-video out is interlaced, for TV viewing. Film look with 25P? Not so much. :-))

Thanks Frank. But assume we've done enough on lighting, DOF etc. and just comes to the question on 25p or 50i mode. If my target is video and the output is TV, will 25p gives a better filmlook after converting to VCD or DVD? If so, what's the post I should be concern about? (or I just treat it the same as of editing a video shot in 50i?)

Thanks!

That's an editing question which I can not answer. Sorry. Perhaps post that question here:

http://www.dvinfo.net/conf/forumdisp...?s=&forumid=37

Lets go back a bit then to not touching the editing portion.

If only talk about output thro the AV of the camera to a PAL TV (meaning playback a miniDV tape); will shooting in 25p gives better film-look than 50i? (if the "picture jumping" is too much, then that's not "better"!)

Thanks!!

25p will give you motion much more similar to film than 50i. Because the images are only going by 25 times a second, you're essentially mimicking the frame rate of film, which in PAL countries is transferred at 25fps. 50i, on the other hand, gives you 50 images per second (albeit, half resolution images) producing the "video look."

The "problem" with 25p is that you are taking fewer pictures per second, therefore you are left with a lower temporal resolution than you would have at 50i. This lower temporal resolution results in strobing movement if objects or the camera move at a certain rate. This strobing can be seen in filmed imagery quite often, if you're looking for it. The solution is, quite often, to slow down the camera's movement. This is where a good field monitor is essential. Using the monitor, you'll be able to see for yourself if strobing is present and adjust your action accordingly.

Thanks Kenn! I think I got what you mean. So the "too much" strobing came from "too fast camera movement" then.

I was just afraid it'll be like de-interlace in post -- i tried it before on 50i video (premier) and the strobing on normal TV is very bad!

Straight de-interlaced 50i video will render motion exactly the same as 25p footage.

Oh Barry! That's bad news for me then!

I remember that footage was shot at high noon, very fast shutter speed with moving objects moving quite fast with clear image (it's clear because of the fast shutter speed i think). After de-interlface in post, the video is unacceptably strobing on interlace TV but very good in computer monitor (since it's progressive right?). And one more thing, I shot with a tripod -- no camera pan, just moving people (the objects I mentioned above) in front the street.

The problem could be traced to the shutter speed. If you shoot video with a fast shutter speed, it will make the motion choppy.

Try it again with a regular shutter speed of 1/50, you should be much more pleased with the results.

Thanks Barry, maybe shutter speed is the cause.