S-log, prores and noice

[Ola Christoffersson]

I just got my Samurai two days ago and have also upgraded my F3 to S-log capable 1.4-firmware.
Eager to try it out the first thing I did was to record a few shots in my office with high contrast and a lot of shadow at Prores HQ (220 mbit/s 10 bit). When playing back the images in my NLE I was shocked at the amount of noice in the image. Especially in the dark areas. The F3 with internal codec is super quiet with almost no noise at all. Where does this noise come from?! I could also see clearly visible macroblocking in one of the shots. Something I have never seen with the EX-codec!!
Is something wrong with my samurai or is this expected from the "visually lossless" prores codec?

Ola

[David C. Williams]

Superblacks and Superwhites. 0-1023 instead of 64-940. It simply gets concatenated on playback. Also, Quicktime plays back in 8bit in 99% of apps out there.

I have no doubt the actual Samurai file is fine, just borked playback. I cannot wait for DNxHD, Quicktime playback and gamma issues are a real pain...

[Ola Christoffersson]

I don't think that is the problem. I have control over White/black-levels. Using AMA in Avid all levels look correct in the waveform monitor. That would not explain the macroblocking either. I remember Allistair writing something about more noice in prores but was not expecting this.

[Dan Keaton]

Dear Ola,

I want to be very polite in saying this.

Please test your F3 with a nanoFlash if possible.

The nanoFlash uses the Sony XDCam 4:2:2 codec, at various bit rates from 50 Mbps to 280 Mbps, and they are all very low in noise.

And, of course, our Gemini 4:4;4, being a true full uncompressed recorder is 100% free of added noise.

The F3 + nanoFlash is just magic: the very low noise from the camera allows the nanoFlash compression engine the opportunity to devote all of its power on compressing the image since it does not have to deal with noise.

But, please understand that we do not recommend the nanoFlash for recording S-Log.

We recommend the Gemini 4:4:4 for use with the F3 when using S-Log. Besides being full uncompressed, it is 10-bit, and has full support for S-Log, including a built-in LUT, for ease of viewing the images on set, on the built-in monitor or via an external monitor.

[David C. Williams]

All editing software I have knowledge of, including Avid, requires Superwhites to be specifically enabled per project or sequence, sometimes per clip.

If you haven't set that yourself, then your not seeing the full range, and it does look awfully like noise.

I've even had this same issue with large international post houses. Even if I'm wrong in your specific instance regarding the noise, it really is worth you investigating just to get back the extra detail your throwing away.