PLEASE ANSWER regarding different frame rates

[Ayesha Khan]

I'm still playing around with my camera and wanted to know if it's okay to change from 50i to 25f on the same tape?

Will this cause issues with the tape or camera or will it cause issues with capturing in FCP or all or none?

I don't need to keep this tape it's just a play around and if I need to get another tape out for a different frame rate that's cool but by nature I'm miserly. Yep. I have to face it. That's me. Oh, and i like to know stuff, so if you can explain that would be a super bonus.

Cheers!

[Jacques E. Bouchard]

Doesn't matter. The image might jump during payback as your camera switches from one frame rate to the next, but you won't "break" anything. Some editing software might also stop capturing when the frame raste changes and give you an error, but you can just re-start the capture without losing anything.


J.

[Paul R Johnson]

Change formats as often as you like. The editor won't object. Pressing play generates the video - what kind of video it was producing a few minutes before is simply history. Cameras can cope with continuous video where you've pasued and then carried on recording, and they are quite happy with blank bits of tape. The only thing to watch is timecode - when you have breaks in the recording, sometimes timecode becomes discontinuous - and worse, sometimes it can confuse the editor when time seems to have gone backwards - but as long as you remember it isn't continuous - all is well.

[Ayesha Khan]

So in terms of capturing (and this may be one for the mac section)

should I leave a gap so I can change the capture format on FCP or
should I just note down the timecode on the change and enter in two sections or
should I leave it all alone and FCP's really clever and will notice the different frame rate?

[Peter Manojlovic]

Why not leave 30 seconds of colour bars in between??

And when you're done experimenting, come back with the results....

[Ayesha Khan]

I'm pretty sure this is a really dumb question, but, how will that help?

Maybe if I elaborate: Is it just for my reference or will FCP recognise something?

[Jacques E. Bouchard]

Originally Posted by Peter Manojlovic

Why not leave 30 seconds of colour bars in between??

Won't help, you still have to pick a frame rate.


J.

[Ayesha Khan]

Thanks. So if I just capture 50i as one set of footage and then the 25f as a separate I guess that will do right? then I can open up the two projects and have a look that way huh?

[Annie Haycock]

The colour bars will just help you remember when you changed - and stop you panicking when you download into your NLE and possibly get an error message or some strange artifacts.

I find it useful to use colour bars if I finish with one location on a tape, and then move somewhere else, or between one day's shooting and another - just as a reminder.

[Richard Hunter]

I usually put the lens cap on or stick my hand over the lens and shoot a few seconds of black whenever I change anything like that. Helps to identify where the changes are in the editor.

Richard

[Annie Haycock]

I do that if I'm recording sound only. Possibly not the best option, but I got into that habit early on, if I didn't have a decent picture to go with the sound I was recording - otherwise I'd be at risk of throwing the clip out for looking bad.

[Roger Keay]

Originally Posted by Ayesha Khan

I'm still playing around with my camera and wanted to know if it's okay to change from 50i to 25f on the same tape?

I have a North American standard XHA1 that supports 60i and 30F. As far as I have been able to determine, changing from interlace (i) to progressive (F) does not actually change what is written on the tape - the image is stored as even and odd fields. What changes is the way that the sensor captures the image. In Frame mode, the sensor captures one image every 1/30 of a second and then writes it to tape as two fields. In interlace mode, the sensor captures an image every 1/60 of a second and writes alternating even and odd fields. The XHA1 camera only plays back in interlaced mode so the difference is not apparent on a monitor except possibly in the rendition of moving images. On an LCD or plasma screen, the edges will tend be blurry on the moving object with interlace capture while the edges should be more distinct but possibly exhibit some judder with progressive capture The results probably depend as much on the HDTV signal processing as the recording so this is a guideline only.

I have record 60i and 30F sequences consecutively and they play right through without breakup. The i and F sequences only become significant when the HDV data is transferred to an editing program using the IEEE (Firewire) interface. Metadata included with the recording lets the edit program recognise the difference between segments recorded as interlace and those recorded as progressive (F mode). A project set for 30 frames per second progressive recognises the two fields as a single progressive image and reassembles them. I think the same thing would apply in the 50 Hz world except the rates would be 1/25 and 1/50 of a second instead.

One final note. Interface footage tends to look bad in the preview and program windows of my Premiere Pro edit program due to the conversion in the graphics card between interlaced and progressive. I use the second output on my graphics card to feed HDMI to an LCD HDTV and found the results are much better if the output is set to 60i rather than 60p.

[Florin Berechet]

Hi everybody!
Speaking of interlaced and progressive footage...I used my XH-A1 to shoot some video for a promo clip for the department I work for. I set the camera on 25f as I wanted to have that special cine look of progressive footage. Well, I don't know very much about frame shooting but I tried not to have too many rapid pannings or zooms...Anyway, the footage looks great but still has that jittery motion, I think is called "judder". Those few pannings were made on a fluid tripod, slowly enough I migh say but still that stuttering motion of the details in the picture. And another thing: I shoot some images with cars moving alng the street. The ones in the sharp part on the DOF were shuttering in their motion. The ones at far distance were ok. But how can I have moving sharp objects in progressive footage?
I edited in Vegas Video, project setting were progressive, 1440x1080, in the preview window everything was cristal clear but after rendering (1280x720p, divx codec) everything that involved motion was stuttering. I tried to add a motion blur envelope to the video bus (I thought that it might improve) but somehow, it doesn't affect video as it used to do with SD video. In HD, my video looked more like applying a supersample envelope.
In conclusion, I did wrong shooting video in progressive mode? Should I have done it in interlaced mode and after that deinterlaced by any method?

[Joe Gaetani]

Originally Posted by Florin Berechet

Hi everybody!
Speaking of interlaced and progressive footage...I used my XH-A1 to shoot some video for a promo clip for the department I work for. I set the camera on 25f as I wanted to have that special cine look of progressive footage. Well, I don't know very much about frame shooting but I tried not to have too many rapid pannings or zooms...Anyway, the footage looks great but still has that jittery motion, I think is called "judder". Those few pannings were made on a fluid tripod, slowly enough I migh say but still that stuttering motion of the details in the picture. And another thing: I shoot some images with cars moving alng the street. The ones in the sharp part on the DOF were shuttering in their motion. The ones at far distance were ok. But how can I have moving sharp objects in progressive footage?
I edited in Vegas Video, project setting were progressive, 1440x1080, in the preview window everything was cristal clear but after rendering (1280x720p, divx codec) everything that involved motion was stuttering. I tried to add a motion blur envelope to the video bus (I thought that it might improve) but somehow, it doesn't affect video as it used to do with SD video. In HD, my video looked more like applying a supersample envelope.
In conclusion, I did wrong shooting video in progressive mode? Should I have done it in interlaced mode and after that deinterlaced by any method?

Try bumping up your shutter speed. Too low of a shutter speed will cause the "judder."

[Florin Berechet]

I used 1/150, even more as the light permitted.