xavc vs avchd

[Dave Blackhurst]

Coming from experience with the AX100, RX10, and a little with the RX100M3....

I shot several test scenes with the AX100 when I got it, AVCHD, XAVCS, and also 1920x1080 vs. 4K. I would not shoot AVCHD again, but that's just an opinion.

I also shot a multicam with AX100, 2x RX10's, the fast card I ordered for the second RX10 didn't arrive in time, so that cam had to stay in AVCHD mode - I can use the footage from the camera, and I venture that most viewers wouldn't notice when all is said and done. Looking at it while editing makes me sad. Again, I would not even think about shooting lower bitrate AVCHD ever again if I had the choice.

That said, I've shot plenty of nice looking stuff with AVCHD along the way (usually highest bitrate 60p) and "it'll do", but just as many of my older photos look "dated" now I'm using a 4K screen to view them, and the "little flaws" that weren't big before now jump off the screen, I wouldn't want to shoot in a format that will not look good in a few years, if I can shoot in one that is more likely to still look "current".

Just my take on it, and BTW, Vegas chomps through XAVCS just fine here, eagerly awaiting the new firmware for 100Mbps that is rumored! OK, had to build a hot rod editing platform, but it was not overly expensive to update a machine that was already overdue!

[Ron Evans]

Originally Posted by Anthony Lelli

With Vegas (made by the same Company) you have to "transcode". No other way. and what you say makes sense if it wasn't for the fact that the "more data" are added by the software (Catalyst, also made by the same Company) after the fact. you start with (say) 100MB mxf and end up with 500MB mxf (same XAVC). then it takes forever, it will write the 100MB mxf again into the hard drive somewhere, plus the new 500MB. Result? the same as the AVCHD. Makes sense? no.
and the same is happening to the XAVC-L of the FS7.

Well it isn't the same XAVC. XAVC-L is Long GOP, XAVC is iFrame. So yes iFrame XAVC ends up being a file of about 5 times the size of the Long GOP file and about 4 times the data rate so more of a test for your hard drives. On the PXW-Z100 shooting 4K a 64G card lasts about 12mins !!! That is the whole point of Long GOP encoding to take up less space and with a lower data rate so it is easier on the camera and memory requirements. Sony , at the moment, have XAVC ( iFrame ) 10bit 4:2:2, XAVC-L Long GOP 10bit 4:2:2 both mxf wrappers, XAVC-S 8bit 4:2:0 mp4 wrapper and just introduced as UHD on the PXW-Z100 8 bit Long GOP 4:2:0 mxf wrapper. They are all basically H264 anyway but at the highest level but they are not the same !!! Of course as an Edius fan Edius edits them all native. I also believe Premiere CC does as well.

Ron Evans