Hd formats

dougs wrote on 7/18/2010, 4:50 AM
I have just added to my sony dsr 450 camera kit a sony PMW 350 xdcam ex HD camera. I am going through the process of looking at the different formats available. Do some put formats less strain on vegas than others. Ie does the 25mb/s 108025p or 50i put less strain on than the 35mb/s hq format? is the 720p option even less taxing? Is 50p more taxing than 25p? Can i ask also , shooting 25p requires a 1/50 shutter for correct sensor expsoure to the image sensors, is it essential to use shutter, most likely 1/100 when shooting 50p? as this obviously cuts down the light to the sensors. And finally are there rendering requirements within vegas to get good results when rendering to an mpeg2 file for use in an SD DVD. From my tests i found that with fast moving sports footage 1080 50i worked best with interpolated fields as opposed to the template setting of "Lower field." The reason for all the questions is i have a job coming up where i will be shooting hand held grabs (crash zooms etc..) indoors low light, which then has to be edited overnight in vegas and delivered sd DVD. So i am trying to work out which of the HD formats might work best for this. Thanks for any assistance.

Dougal F.
Vegas pro 9e 64 bit
Windows 7 on a sony i7 VAIO laptop.

Comments

JohnnyRoy wrote on 7/18/2010, 8:01 AM
> Do some put formats less strain on vegas than others.

Yes. The greater the resolution the greater the strain and the greater/more complex the compression the greater the strain. So DV with it's low resolution and intraframe compression edits extremely smoothly, but HDV with it's greater resolution and interframe compression is harder to edit but still much smoother than AVCHD which is highly compressed and difficult to work with.

> does the 25mb/s 108025p or 50i put less strain on than the 35mb/s hq format?

Not on your CPU but on your hard drives. Higher bitrates are usually less compressed and actually easier to edit. You need to be able to stream them off of the disc faster.

> is the 720p option even less taxing?

Yes, less resolution, less taxing.

> Is 50p more taxing than 25p?

Yes, more frames per second is more taxing.

> Can i ask also , shooting 25p requires a 1/50 shutter for correct sensor expsoure to the image sensors, is it essential to use shutter, most likely 1/100 when shooting 50p?

Yes, your shutter should be at least twice your frame rate so 50p should use 1/100.

> And finally are there rendering requirements within vegas to get good results when rendering to an mpeg2 file for use in an SD DVD. From my tests i found that with fast moving sports footage 1080 50i worked best with interpolated fields as opposed to the template setting of "Lower field."

Fast moving interlaced footage which probably have too much motion between the fields and so blending doesn't work well. This is why interpolate looked better. What it did was throw away half of the fields so you sacrifice vertical resolution.

> The reason for all the questions is i have a job coming up where i will be shooting hand held grabs (crash zooms etc..) indoors low light, which then has to be edited overnight in vegas and delivered sd DVD. So i am trying to work out which of the HD formats might work best for this. Thanks for any assistance.

If it's fast motion and you can shoot progressive, that would be your best choice. This would eliminate any interlacing problems. Since you are delivering in SD, 720p should be fine.

~jr
dougs wrote on 7/18/2010, 4:47 PM
Thanks Johnny for taking the time to address the many questions in my post. Much appreciated.