JVC GY-HM700 vs HMC150 or HPX170: Bit Rate

[Ryan Mast]

You’re right, it’s apples to oranges. The better question to ask is which camera solution best fits your workflow needs.

The JVC HM700 and HM100 are always shooting to the same codec, but you can change the wrapper. The MOV wrapper is great for FCP, but MP4 is better for other NLEs.

A quick solution to the workflow question is to shoot with a AJA ki or something similar. ProRes HQ is higher bitrate, color resolution, and bit depth than any of those camera’s codecs.

[Isaac Brillant]

Thanks for the reply.

Really the main thing I like about the GYHM700 is how it feels on your shoulder.

I’ve heard though, that when you transcode to Prores you lose 5 to 1 of the bit rate, so if you start with 25mbps, the prores file is only 6 or so. Is there any truth to this?

Thanks

[Ryan Mast]

[Isaac Brillant] “Really the main thing I like about the GYHM700 is how it feels on your shoulder. “

I’d been debating between the JVC HM700 and the Panasonic HMC150, but the professional form factor and workflow of the JVC won me over. I like my HM700 a lot. =)

[Isaac Brillant] “I’ve heard though, that when you transcode to Prores you lose 5 to 1 of the bit rate, so if you start with 25mbps, the prores file is only 6 or so. Is there any truth to this?
“

Other way around. ProRes 422 for 720p30, for instance, is ~110 Mbps for 10-bit (HQ), and ~73Mbps for 8-bit. Unless your originating format is 10-bit, stick with 8-bit for transcoding. ProRes has a 3-4 times higher bitrate than XDCAM EX on the Sony EX1/EX3 or JVC HM100/HM700.

[Kent Hamson]

XDCamEX
XDCamHD (same thing?)
HDV (mpeg2)
AVCHD (mpg4)
DVCProHD
and
Whatever codec JVC uses

TheXDCamEX, XDCamHD and JVC codec are all the same.

As for the quality having shot and edited all of these formats, plus a few others. Rating from best to worst:

AVC-Intra (Mp4 w/no LongGOP used in Panasonic HPX300/HPX370)
DVCProHD
XDCamEX
AVCHD
HDV

AVC-Intra and DVCProHD record 422 color at 100mbps
XDCamEX is an Mpeg2 at 35Mbps
AVCHD mpeg4 at ~21Mbps
HDV mpeg2 at 25Mbps

an mpeg4 will get double the quality of an mpeg2 in half the bit rate. Essentially a 13Mbps AVCHD is equivalent to an HDV 25Mbps except it will not have blocking issues in fast movements on screen.
A ~21Mbps AVCHD would be about like a 45Mbps Mpeg2.

All the technical data aside it really doesn’t make a lot of difference what the capture codec is. They all produce wonderful video files if lighting is good.

The most important thing in a camera is the needs of the shooter and the workflow for post production. Find a camera you can hold and use comfortably and suites your shooting needs.

If using FCP AVCHD may not be the best choice since you would have to wait for the computer to convert all the video to Apple ProRes. The DVCProHD and EXCam imports into FCP with ease.

I use Sony Vegas for editing and can’t import the mp4 files from the JVC GY-HM700. All my AVCHD footage and DVCProHD (with the DVFilm raylight plugin) is import and edit.

Premiere CS5 is supposed to be able to bring all of them in natively, if you believe Adobe that is.