DVCAM and DV capture

When outputting from PC to Camera via Firewire, my camera can record in either DVCAM or DV. I'm wondering though, is there any difference between the two?

If you record in DVCAM, I'm assuming the 'bit rate' is faster because it records at a third faster - but when capturing footage, there is no 'DVCAM' or 'DV' capture setting, so when capturing footage does it just scale it down to 'DV' anyway?

Because I'm not sure whether I should record DVCAM edits in DVCAM or just DV if it makes no difference, 'cause of course DV gives 20 minutes more recording time.

So my question is, does DVCAM scale down to DV on capture, and, if you have an edit with footage shot in DVCAM should you output back to camera with the camera set to record in DVCAM?

[Mike Kujbida]

Originally Posted by Jonny Brady

When outputting from PC to Camera via Firewire, my camera can record in either DVCAM or DV. I'm wondering though, is there any difference between the two?

The ONLY difference between DVCAM and DV is the tape speed.
The theory behind it is that the higher tape speed will result in less noticeable dropouts if they do happen.

So my question is, does DVCAM scale down to DV on capture...

Since the signal is identical, nothing (like scaling) happens during the capture.

...if you have an edit with footage shot in DVCAM should you output back to camera with the camera set to record in DVCAM?

That's entirely your choice.
It can also depend on who you're giving an edited master to.
Some TV/cable stations prefer DVCAM but this is something that needs to be determined ahead of time..

Ahhhh right, I see. Dropouts. I'll have to look that up to see how that works.

Cheers

[Mike Kujbida]

The tape is running faster therefore a dropout would be spread across a wider section of DVCAM tape than a miniDV tape.
See Adam Wilt's DV, DVCAM, DVCPRO FAQ for more info.

Don't understand how that makes the dropouts less likely but no need to explain. Haha. Cheers :)

[Ron Evans]

The tape in DVCam camcorder runs at 1.5 times the speed in a DV camcorder. Same tape so run time for DVCam is 40mins and DV 60 mins for the standard mini tape. The camera creates the "1's and 0's " to write to tape at the same rate for both formats, 25Mbps. So DVCam will use up 1.5 times the amount of tape of DV to record the same "1's and 0"s ". The data is spread out over 1.5 times the area of magnetic material so any defects in this magnetic material will have a smaller effect on the data stream. Because the error correction data is also spread out the overall result is more than the "1.5 times better" one might simplistically assume. All this is significant if the tape is being used in a decks based linear editing system which is what was used prior to the digital evolution of video. With NLE systems the repeated use ( shuttling etc) of linear editing is gone, also the tapes have improved so that dropouts due to poor tape are also rare. Consequently the value of DVCam over DV is limited and once the data is in the NLE there is no difference even though on tape there is a tape format difference. DVCam has locked audio( audio samples are locked to the video frame it refers to, while DV can have up to a 1/3 frame offset).Again for linear edit with syncronized decks locked audio is a must. However several DV camcorders( JVC Pro units) also have locked audio and in this case there is no difference.

Ron Evans