-
FCP Experiment (5 minutes).. .try it yourself
I already posted about this, but realized I asked the question in the wrong way. So I wanted to do it again because I find it interesting – and possible has implications what FCP does in its processing. It takes about 5 minutes to test this out yourself.
Start a new project and in the sequence settings set the sequence to uncompressed 8 bit or 10 bit. 1920×1080, and any fps.
Then, in the Viewer, hit the “A” button in the bottom right of the viewer. Then Render > Gradient.
You will have created a 10 second white to black gradient in the viewer.
I have a basic $220 23″ LG monitor. In the viewer I see a very nice white to black gradient with no banding at all. If I then drag the clip to the timeline/canvas the same clip has quite a lot of banding.
At first I thought the timeline must be degrading it a little to help clips play in real time. So I exported the timeline to a clip with the same uncompressed settings – same bit rate, etc. I then imported the same clip into FCP and into the Viewer where it was created in the first place and where there was no banding.
I expected in the viewer to see exactly what had been created there. It was the same clip but it had just taken a little journey. But no. The clip now had banding.
What I’m trying to figure out is why something that looks so nice in the viewer, when moved to the timeline and exported at the same settings is being degraded.
Normally you would not see this, but with the gradient you can see the subtle degradation with the banding.
I’m very curious if others are getting similar results.
-
6 Replies
-
I’m by no means an FCP guru, but I would say the problem comes from the 8/10 bit compression
System
Mac Pro 2.8Gb quad core
8Gb RAM
1x 320Gb 7200 hardrive
1x 1Tb 7200 hardrive
Nvidia Geforce 8800 512mb Graphics card
1x 1Tb external WD ‘My Book’ eSataEquipment
Panasonic AG-HVX 200
Firestore FS-100 -
David,
[David Smith] “Then, in the Viewer, hit the “A” button in the bottom right of the viewer. Then Render > Gradient.
You will have created a 10 second white to black gradient in the viewer.
I have a basic $220 23″ LG monitor. In the viewer I see a very nice white to black gradient with no banding at all. If I then drag the clip to the timeline/canvas the same clip has quite a lot of banding. “
What looks so good in the Viewer is not a clip, but a graphic that is being generated by FC.
So when you drag the Gradient from the Viewer to the time-line you are not dragging any clip.
Only when you render that graphic on the sequence you get a clip.As I mentioned, FCs Generators works 8bRGB.
so YOU WON”T GET A 10b GRADIENT FROM FC.
The reason of the banding and the ways to avoid it has been explained in your other thread.
rafael -
[Rafael Amador] “As I mentioned, FCs Generators works 8bRGB.
so YOU WON”T GET A 10b GRADIENT FROM FC.”Sorry, but this is BS.
-
I have banding immediately upon adding the gradient to the viewer. Test over here.
My Monitor DELL SX2210 Display and my card is ATI Radeon HD 5770 1024 MB graphics
Bottom line is that if it’s banding anywhere and it bothers you, then you need to take steps to make it not band, because you don’t know what your viewer will see it on – 8 bit or 10bit. It’s been demonstrated just how hard it is to keep a 10bit path so I’m pretty sure nobody on the net or watching on TV will get a 10bit image.
-
[Bret Williams] “Bottom line is that if it’s banding anywhere and it bothers you, then you need to take steps to make it not band, because you don’t know what your viewer will see it on – 8 bit or 10bit.”
And a blur or a dither can hide some of that, as can adding a bit of noise to break up the pattern, but it’s a blur, dither or noise; good for things like gradients (text with a gradient BG or something), bad for things like faces. The truth is, 8 bit is going to band somewhat. 10bit bands less, and the amount of banding and how it’s displayed will be different on every monitor. As far as I know, there’s no 10bit web deliverable quite yet, it’s all 8bit, as is broadcast.
It’s not hard to keep a 10b signal path in FCP7. It’s all 10b if using 10b material and using a codec like ProRes or 10b UC. It’s the transcode after that that will get knocked to 8bit. That’s why you deliver the highest quality master you can as you cannot control everyone’s screen (some monitors aren’t even 8bit).
-
There is a filter in FCP under image control called reduce banding as well.
Reply to this Discussion! Login or Sign Up