Michael Gissing
Forum Replies Created
-
Broadcast specs are simple. In SMPTE land tone on a digital machine is 1khz @ -20dbfs (db full scale). In the PAL world either -20 or -18dbfs is acceptable. Peak levels are then no more than 10db ABOVE that reference.
It is important to remember that professional digital machines have high gain analog outputs. If you use -12db tone and then had program levels peaking 10 db above that, then you would be sending high levels to any analog machine, running the risk of overloading the input circuits. That is why some digital machines let you trim the analog output level from professional +4db spec to 0db or even -10db domestic level specs.
Whilst it is important to realise that tone is just a line in the sand and totally irrelevent for digital to digital transfers, it does represent an important reference for analog dubbs. So best practice is to follow the broadcast spec. It is mandatory for most programs and should be considered the best standard for all work. I find it unusual that FCP defaults to -12db with its tone generator. But the golden rule is peak levels shall not exceed 10db above the reference.
-
Sorry to barge in on this thread, but I just wanted to thank both Peter and Christoph. My last jobs have needed Peter’s 30 sec BBC clock and Christoph’s plug ins have been fantastic – fixing dropouts, doing credit rolls and jazzing up transitions. I have just scratched the surface but very impressed so far.
-
The green/blue key filter or the chroma key filter are better than the color key filter. I find the green/blue works OK for a quick key, wih the chroma key filter giving a bit better control. However, if you know how to get a good key in motion then that may be better than FCP. I have also just purchased the Nattress filters which are meant to help particularly with DV and HDV to smooth and process chroma to give better keys using the FCP keyers.
I have had fairly good results with the FCP keyers, but using well shot digi beta, I know there are other key software packages out there that make FCP seem ordinary.
-
For software conversion try the Nattress Conversion software plug in.
I have just downloaded the demo so I can’t tell you how it might compare to a hardware converter like a Teranex.
-
What are you to deliver? If the program is for broadcast then use the 1080 50i setting. I use that setting with the Decklink Blackmagic card for broadcast HD, even with HDcam shot at 25p. Better to check the deliverable requirements first.
If it is for scan to film then 1080 25p setting is more appropriate, but again, ask the people who are doing your scan to film (if that is the path).
-
What is the HDV Deck set to? If it is like the cameras, you have to set the video rate and whether it is down converting. If you want to play a PAL DV tape then it should be set for 50i and the output set to DV. The fact that it worked for NTSC suggests that the deck is not set for PAL playback, rather than anything to do with FCP settings.
-
Matte, NTSC is not real time.It measures 30 frames every 29.97. The dat is real time so the drift is the same as the rate of time drift in 29.97. DF is the way to keep the frame count the same as real time, but it is a fudge.
On my sample rate converter, 47.952 is a standard preset that is used to correct this drift. If you are starting with 44.1khz, the magic correction is 44.056. I deal with PAL mostly, but we are aware of the problem as we deliver to you poor NTSC suffers
-
Dat to aif, burned to a CDRom doesn’t require a sample rate change from 48khz to 44.1khz. So if that is happening, it is unnecessary.
There is a slight drift between DAT 48khz and 29.97 frames rates. Tell your sound man to sample rate convert the original files from 48khz to 47.952khz to correct this drift. It is caused by the difference between 29.97 and 30 frames per second. On short grabs, you won’t notice. Anything longer than a minute and you will have drift.
You might be able to use quicktime conversion to change the aifs to 47.952. I haven’t tried this as I do all audio processing on other systems, but it should correct the drift.
-
Michael,
I control the Canon via firewire, but in the Xl1 menu you have to set the camera to downcovert out the firewire. It still outputs the HD SDI, but you change the machine control setting in FCP to firewire dv and it should give you frame accurate sync & control. Certainly does for me, although I am using PAL 1080 50i.
-
John, I am mostly reconforming and deal with mixed formats so I know the problem. I like editors to log the reel number as the first part of any clip description. I then batch capture Digi beta reels, HDV etc based on the reel numbers by selecting those clips in the bin.
Alternatively, just batch capture the whole sequence and it will tell you which reels it needs. Skip to the reels in the format you are patched for. Repatch and skip to the HDV reels etc. I don’t care where in the sequence they are. The clips in the bin will show what is offline. Having the reel name in the clip description helps to target. A further refinement is to use reel numbering systems that denote format. ie all digi beta tapes are 100 – 199, DV 200 – 299, HDV 300 – 399 etc