10 Bit Cameras

[Andrew Stone]

Just had a look at the NeatVideo noise reduction plugin. Astounding.

[Dean Harrington]

I use the NeatVideo plug-in religiously ... best when used on original material when first put on a timeline before you do anything else. It can be time-consuming but the results are very good.

[Simon Wood]

Dean,

Could you walk us through how you use the neatvideo plug-in (especially if you are using the nanoflash footage)? I'm interested especially to know how many 'generations' you need to render, and whether this has an impact on the final quality at the end?

[Dean Harrington]

Originally Posted by Simon Wood

Dean,

Could you walk us through how you use the neatvideo plug-in (especially if you are using the nanoflash footage)? I'm interested especially to know how many 'generations' you need to render, and whether this has an impact on the final quality at the end?

If you download the plug-in ... I use it in FCP ... you can take a section of a frame within a section with uniform coloring (black for example) and have the plug-in analysis the noise in RGB. It will provide a % of noise present in the frame. If you are satisfied with that % reading say 40% to 50% then proceed to apply that percentage of clean-up in the sequence that was shot within that period. You can do this nested on a whole timeline if the sequence was shot in the same way during the same session and then render. It's really as simple as that. I encourage you to give it a try. There is a numeric value you can apply ... from 1 to 5 adaptive ... that reflects slight or major adjustment if you wish on the fly but I tend to get an analysis of sections and find that is more accurate.
ps ... if this is the first thing you do on material in a time line ... you don't need to adjust for noise again.

[Rafael Amador]

Dear Piotr,

The problem is that your "little theory" is built on top of misconceptions.
Sorry to say, but you are not very clear some basic concepts.

"Dan Keaton explained that for every 1bit, you need a clean 6db of sensitivity. With the EX1's measured sensitivity of 48db, there is only 8bits of info available".

Statements like that makes no sense at all. You are mixing there Analog concepts (SIGNAL to NOISE RATIO, BAND WITH) with digital elements (BIT DEPTH).

The "Signal to Noise Ratio" tells the quality of any system (video or audio), and of course will have impact in the picture quality, but is not exactly the "picture noise".

Again Piotr, whatever the camera you have, will ALWAYS be better to record that in 10b than in 8b.

Instead of trying complicated tests:

- Take the VIDEO COMPOSITE out of any cheap MiniDV camcorder.
- Set Color Bars out of the camcorder.

Record that at 8b Unc and at 10b Unc and compare.

Rafael

[Simon Wood]

Thanks for that. So once you have established the correct amount of noise reduction you then render that sequence to the same format as the original (nanoflash mxf/mov codec), or is it changed to something different?

Any further colour correction would then be done on these new files?

[Dean Harrington]

It depends on your final output. I find prores produces the best output for the net and TV but you can play with this master. You color correct after you've done the noise cleanup. You can output from the master at H.264 if you want via compressor or Flash via Adobe Flash if you have that software. On my reel on exposure room ... I out put a commercial 'Andy's Fish' to flash for the net. It's very clean.
Andy's Fish By Dean Harrington On ExposureRoom

ps ... this was shot long GOP 100 ... you might prefer 50 but that's your choice.

[Simon Wood]

Got it - thanks!

[Piotr Wozniacki]

Originally Posted by Rafael Amador

Dear Piotr,

"Dan Keaton explained that for every 1bit, you need a clean 6db of sensitivity. With the EX1's measured sensitivity of 48db, there is only 8bits of info available".

Statements like that makes no sense at all.

Dear Rafael,

I guess you're confusing things, and who said what. The above statement from Dan has NOT been a basis for my little theory (in fact, it doesn't convince me at all, either).

As a matter of fact, my feeling is that the 2 of us mean the same, just using different wording...

Piotr

[Dan Keaton]

Dear Friends,

Just to be clear, I do not believe that it was me who made that original statement.

[Rafael Amador]

Dear Dan & Piotr,
Sorry I didn't intended start a discussion about who said this or who said that.
I'm pointing to statements that needs to be proved and to and to wrong concepts.
We are mixing the "Camera noise" with the concept of Signal to Noise Ratio and the 60dbs implied in 10b sampling.


And statements like this "the EX1's measured sensitivity of 48db" needs to be explained.
Who have measured that and how?

About the 8b/10b-Camera Noise relation, and in short:
When you sample a Video signal with more or less precision (10b vs 8b) you don't only sample the picture with more or less precision: You will be also sampling the noise with more or less precision.

This won't changes the noise, BUT If you sample the noise with more precision, you can clean the noise with more precision.
That's what matters.
rafael

[David Heath]

Originally Posted by Rafael Amador

No sense.
Bit depth is a format setting.
Is the number of bits you use to sample an absolute value (luma, chroma, sound,..)
Has nothing to do with noise, sensitivity or whatever.

No, fundamentally Steve is right. Bit depth does indeed define the number of variations in the shade of an image - 256 for 8 bit, 1024 for 10 bit - but if the noise is greater than the differences in level represented by the least significant bit, resolving to the 10 bit level becomes a bit pointless. And that's the case for all but the most expensive cameras.

If you have a set of scales accurate to + or - 2 grams, what would be the point of having a set of weights that would allow you to measure to 0.1 of a gram?

If a perfect mid grey would resolve to a level of 128 in an 8 bit system, then noise may mean in the non perfect world it will be between 125 and 131. Go to 10 bit, and the same scene will give values between 500 and 524. All the 10 bit recording is really doing is resolving the noise more accurately. The fine gradations in the image tone become masked by the noise.

And 10 bit will mean a 25% increase in data rate to keep all else equal. That data may be better used in reducing overall compression, rather than increasing bit-depth. Not just bit depth, but also compression can give banding, especially if less data is allocated to chrominance wrt luminance. (Try forming a gradient in Photoshop and making a JPEG on maximum compression if you don't believe me.)

[Jim Arthurs]

Just as a fun bit of history, the Quantel Domino system scanned 35mm motion picture film and saved oversampled images at approx 3K, and those files were 8 bit.

If you think that's severe, at the time, Quantel claimed that they could actually reproduce the picture perfectly in 6 bits, and the last two bits were just for grain/noise!

Kodak took a different, 10bit log approach with Cineon, but many, many feature films have shots and sequences run through totally in the 8bit domain via Domino. Movies like Stargate, First Night, Lost in Space, etc.

Regards,

[Steve Kalle]

Hi Dan,

I tried to find the post about 1bit per 6db of S/N but I haven't had any luck. I honestly thought that it was you who posted this. If it was you, can you provide an explanation again about 1-bit and 6db?

I do know that many others including Alister have said that recording 10bit from a noisy camera does not add much quality if any, and I must defer to him as he is far more knowledgeable due to his engineering background.

Thanks

[Dan Keaton]

Dear Friends,

I take no offense whatsoever about the 1 bit quote.

I do not know who originally said this and while it makes sense to me, I do not know if it is technically accurate or not. My best guess is that is probably accurate, I have just not studied this concept in detail.

I do agree completely with Alister and others that some camera's that technically have a 10-Bit HD-SDI output do not have a low enough noise floor to make the 10-Bit truely useful.

On the plus side, the Sony PMW-F3 is one of the great cameras, especially in its price range, as it is an extremely low noise camera. Thus the 10-Bit's of the F3 are very useful.

The funny part to me about all of this is that since the F3 is such a low noise camera the 8-Bit nanoFlash works extremely well with this camera.

This is a direct side benefit of it being such a low noise camera. The nanoFlash does not have to waste any of its compression power on compressing the noise, thus it can produce just stunning images.

One of the reasons that the nanoFlash shines in this application is that the Sony XDCam 422 codec that we use is an especially low noise codec.

When our Gemini 4:4:4 ships, it will be ideally suited for the F3.

The Sony F3 + S-Log Firmware Upgrade + Gemini 4:4:4 is going to be just magical. Especially when one considers the price of this combination.