Noise in AJ-HPX 2000P

[Jim Wilcox]

Jeremy,

Thanks for the feedback. I have found that tweaking the knee does help. The still I sent was right after we got the camera, so I had not tried that. But, since you don’t see it monitoring the camera on-set, I assumed it was a compression issue, John.

Just read the article last week – Really interesting. Do you find that shooting AVC-I 50 has similar issues (4.2.0 color etc)?

[Jeremy Garchow]

[Jim Wilcox] “But, since you don’t see it monitoring the camera on-set, I assumed it was a compression issue, John. “

When monitoring on set, you are seeing pre-compression (or an uncompressed) video signal. Clean as a whistle. What you can do though, is tweak the color settings to favor compression, and knee/gamma has a lot to do with that as DVCPro HD seems to get a bit noisier in darker areas of images.

We don’t shoot AVC-I 50. It doesn’t really fit our needs. AVC-100 has been terrific though. 4:2:0 is something we aren’t really interested, but I could see where it’d have its place, especially at such a low bandwidth and to still be an I-frame codec.

The biggest problem right now is AVC-I not being enabled in FCP. Currently, the ONLY way to get a 10-bit decode of AVC-I material in OSX is to use log and transfer. This process works well and results in great looking images, but log and transfer completely strips any and all metadata which renders it useless. This is extremely frustrating and this problem would be solved if Apple would take the AVC-I codec over like it did for DVCPro HD. I encourage anyone who is using AVC-I to please send feedback to Apple to get this fixed and sorry for the mini rant. I have to say it, but the new iPhoto can read and create new metadata, but FCP can’t. iPhoto is part of suite of apps that costs $75 US.

https://www.apple.com/feedback/finalcutpro.html

Jeremy

[Jim Wilcox]

Jeremy,

So even muxing with software like Calibrated or MXF4Mac is not keeping AVC-I in 10 bit (thought I remember you mentioning that in your article)? That would suck. But so does having to transcode everything to ProRes HQ.

[Jeremy Garchow]

[Jim Wilcox] “So even muxing with software like Calibrated or MXF4Mac is not keeping AVC-I in 10 bit (thought I remember you mentioning that in your article)?”

Nope. It does not as AVC-I is not enabled in Quicktime as a real time encoder and decoder and the only decode that happens gets stuck in an 8-bit SMPTE range due to apparent limitations with Quicktime. This means Apple needs to write the codec for real time functionality in FCP/QT just like they did for DVCPro HD.

If you use P2LogPro v3 (or any Imagine product), it will also make QT movies and send the metadata via XML to FCP, but it’s an 8-bit decode only. They don’t tell you that when you buy it. Currently, the only way to get a 10-bit decode is log and transfer (which works just fine) but takes a while and there’s no metadata. To us, it’s worth the wait right now as 10-bit is key to our workflow. If you are using a strictly DVCPro HD workflow, then I’d suggest using a program called MXF4mac which allows real time editing of p2 media complete with metadata:

https://library.creativecow.net/articles/garchow_jeremy/dvc_pro_hd.php

Jeremy