mpeg2 hdv and editing

[joshtownsend]

I understand that the JVC gets great images at 24p, but what bitrate does it record the mpeg at? If I were to shoot hdv then I have to edit with mpeg2 footage right?

Do multiple video tracks and more effect make for a worse final image because of the MPEG2 compression?

One last thing does the lens that comes with the jvc have a shallower depth of field than the wide angle hvx200 or dvx100 lens? Is it easier to acheive CU and medium shots with blurry backgrounds with the stock lens than the DVX?



Trying to decide between the jvc and panasonic. It's either buy a lens or buy P2 cards. I shoot movies so the P2 cards low capacity doesn't bug me. I can dump the info while we set up the next shot.

thanks

josh townsend
www.loyaltythemovie.com

[Editor321]

So....your decision would rely on how each of the cameras footage look "blown-up" on the big screen. I dont see how we would ever get blown up footage side by side.

But, on paper it looks like the HVX200 would win

Which prompts another question regarding capacity and P2, I know that there are many takes even in a simple scene. Actors say the wrong word, unwarranted laughs, not enough emotion, etc,. Or just wanted to get 2 takes of a good scene for backup purposes. If I was to do 10 takes on a 2 min scene, it seems that I would be limited (trying to get that perfect take) unless I had plenty p2 cards. No?

So, I guess it all comes down to those green backs. If you have it to spend on P2's, you have no probs.

[Barry_Green]

I understand that the JVC gets great images at 24p, but what bitrate does it record the mpeg at? If I were to shoot hdv then I have to edit with mpeg2 footage right?
Yes. The JVC stores 24p footage in a 19-megabit MPEG-2 bitstream. And yes, you would be editing that MPEG2 footage, unless you cross-convert (transcode) it to an editing codec, such as Cineform's.


Do multiple video tracks and more effect make for a worse final image because of the MPEG2 compression?
Well, recompressing down to MPEG2 again would make for a worse final image, yes. But that's not typically how editing programs work. You usually only execute a re-render or a final render at the end of the project, if possible. If you're doing re-renders and re-imports during your edit, you would definitely want to use an intermediate (or uncompressed) codec; recompressing to MPEG2 will quickly show an unacceptable level of artifacts and compression buildup. Check Adam Wilt's article about it in this month's DV Magazine, May 2005.


One last thing does the lens that comes with the jvc have a shallower depth of field than the wide angle hvx200 or dvx100 lens? Is it easier to acheive CU and medium shots with blurry backgrounds with the stock lens than the DVX?
Yes it would, if you used it at full telephoto (zoomed all the way in). If you use it at the same focal length as the other cameras, it will exhibit identical depth of field as the other cameras. But if you can back up and zoom all the way in, you can get shallower DOF with the JVC than with the other cameras.

The JVC's lens has a longer telephoto, up to 88mm. The DVX maxxes out at 45mm, and the HVX maxxes out at about 60mm. The longer the telephoto you set the lens to, the more out-of-focus the background will look.

[Gibby]

One last thing does the lens that comes with the jvc have a shallower depth of field than the wide angle hvx200 or dvx100 lens? Is it easier to acheive CU and medium shots with blurry backgrounds with the stock lens than the DVX?

Josh-

With the shorter focal length DVX and HVX fixed lenses you can still achieve a more narrow depth of field by moving the camera back farther from the subject of focus, re-focusing, and opening up the aperture. A faster shutter speed and/or the use of more ND filtering, in-camera and/or on the front of the lens, will then allow you to open up the aperture - thus narrowing the depth of field. As Barry has noted, it is easier to get a narrow depth of field with a longer focal length lens. With the shorter lens of the DVX and HVX you have to work a bit more at narrowing the depth of field, by techniques I mentioned above.

Hope this helps!

Gibby
www.cut4.tv

[joshtownsend]

THANKS BARRY

Perfect answers. Exactly what I wanted to know.

The trade off in my mind is longer lens vrs P2 cards and less copression.