7D Compression better than HDV ?

[ksrksr88]

I have Canon HV20 which I like
but I find capturing and pull-down process
very time consuming. So I am looking into purchasing 7D

Can anybody tell me if 7D's MOV compression is
better than HV20's HDV compression ?

Thank you

-J

[tfg]

Canon HV20 is a 25megabit Mpeg2 stream. Canon 7D is a 45megabit H264 stream. 7D is the clear winner by a wide margin.

[Michael Olsen]

Canon HV20 is a 25megabit Mpeg2 stream. Canon 7D is a 45megabit H264 stream. 7D is the clear winner by a wide margin.

At least theoretically. A greater bit-rate alone does not determine the quality of compression...it does look good, though. :)

[manglerBMX]

and its not tape!

[ydgmdlu]

The H.264 implementation would have to be really bad in order for it to not at least match HDV.

H.264 is at least twice as efficient as MPEG-2. The demonstrated 48 Mbps bit rate on the 7D is comparable to 100 Mbps MPEG-2. So on paper, the quality should be four times better than HDV, though HDV is very mature, and Canon's DSLR codec has at least one flaw (lack of B-frames). But as you can see, the implementation would have to be REALLY bad for it to not be better than HDV.

[Barry_Green]

H.264 is at least twice as efficient as MPEG-2 when fully and properly implemented. But leaving out the B-frames severely lowers the compression efficiency. A lot.

Side-by-side testing is required before this question can be accurately answered.

[Michael Olsen]

Side-by-side testing is required before this question can be accurately answered.

Funny how it keeps coming down to this :)

[jdv]

The proof's always in the puddin'! Hopefully, it will pass the eyeball test even if it falls short on paper.

john

[xbourque]

I own an HV20 and I've used 5D2s on 2 separate occasions.

I feel the HV20 compression is pretty good to begin with, and the 5D2 looked even better. The main advantage of the 5D2 (and the 7D) was that it didn't have pulldown baked into video, so it didn't end up with nasty chroma sampling artefacts compared to the HV20. On the HV, when you remove the pull down in post, you often end up with color ghosts on the frames that were reconstructed from two separate frames. Obviously, progressive cameras like 5D2 and 7D do not suffer from this problem.

The only thing that I missed from the HV20 image quality wise was the smoother antialiasing for fine detail on wide shots (like brick walls and such). Otherwise, 7D should be all gravy. :-)

-- X

[Ian-T]

The only thing that I missed from the HV20 image quality wise was the smoother antialiasing for fine detail on wide shots (like brick walls and such). Otherwise, 7D should be all gravy. :-)

-- XDon't forget picture adjustments like "cinemode." A feature that helps tremendously when shooting highlights and lifts up the shadows like crazy. But then again Canon is more likely saving these types of features for their upcoming large sensor camcorders.

[xbourque]

Don't forget picture adjustments like "cinemode." A feature that helps tremendously when shooting highlights and lifts up the shadows like crazy. But then again Canon is more likely saving these types of features for their upcoming large sensor camcorders.

(For the sake of this discussion I'll assume the 7D has the same controls as the 5D2... which it should according to the menus described in dpreview).

If you're implying that one would miss the HV20's "cinemode" on a 7D, I don't agree at all.

The 7D has plenty of "film modes" (standard, neutral, faithful...) and sub controls within those film modes (contrast, sharpness, saturation,...). On top of that, you can shoot a RAW still, load in your computer and open it with the Canon software (Picture Style Editor, I think) and tweak the settings (including a primitive custom gamma curve...). Once you're happy, you can upload the settings to the camera into one of the 3 custom film modes. You use that film mode when shooting movies.

From my limited experience with the 5D2, the color fidelity and soft contrast of the 5D2 blew away the HV20.

--X

[Ian-T]

Oh I'm sure the 7d and 5Dll have some nice picture controls but in regards to cinemode in the HV20 it helps to eek out a little more dynamic range in your footage. I don't expect the color and fidelity of the HV20 to match or come close to these DSLRs. But it is what it is for a cam like the HV20. If you say the gamma settings on these DSLRs are "primitive" then I was right in suggesting "Canon is more likely saving these types of features for their upcoming large sensor camcorders." I expect them to be more robust on video cams than these cams.

[xbourque]

By primitive I meant that the actual curve editor in the software is not very good. It creates bizarro curves way to easily. The curve can very complex if you wish it to be, so it's not a limitation of the camera, I think.

On top of that, you can always turn on Hilite Tone Priority in camera if you want a nicer rolloff in the highlights.

The stuff Canon will probably do to differentiate future large sensor/photo lens camcorders:

1- "Video" form factor with flip out screen
2- XLR audio
3- BNC HD-SDI video
4- Zebra, peaking, waveform monitor, etc...
5- Less megapixels, better antialiasing
6- More robust codec for post

There's probably going to be slightly fancier in-camera picture tweaking, but the current level of the 5D2/7D is on par with EX1-level cameras, I would guess.