Sigma Fp ALL-I vs IPB - Big difference

[Andrew Reid]

The ALL-I codec on this camera is REALLY good.

Maintains a LOT more in the shadows than the Long GOP IPB mode.

It is 400Mbit so quite big files but a lot smaller than RAW at 1800Mbit.

This is one of those occasions where 400Mbit is worth it...

(Shadows pushed up approx. 3 stops in Resolve)

4K ALL-I

4K Long GOP IPB

[PannySVHS]

Hallo Andrew,  what flavour of ipd codec was it, 8 bit? The 8bit 4K from the Lumix S1 with its slim 100mbit is very strong. None of the artefacts like the example you posted. Seems like Sigma has not implemented the Panny codec.

[rawshooter]

1 hour ago, PannySVHS said:

Hallo Andrew,  what flavour of ipd codec was it, 8 bit? 

The Sigma fp can only record 8bit when it's not recording CinemaDNG.

[rawshooter]

Just ran my own test, because I never used the ALL-I codec before. Lens was an adapted Nikkor 24mm/f2 Ai-s.

Framegrab from the UHD 23.98p ALL-I mov recording:

 

Framegrab from the UHD 23.98p CinemaDNG recording, same lens, graded in Resolve 16 to match the h264 image (roughly), sharpness parameter in the RAW setting left at default value 10:

 

1:1 crop ALL-I mov:

 

1:1 crop CinemaDNG:

 

What I don't like in the ALL-I mov are the pronounced sharpening artefacts (including halos) - although I had dialled down in-camera sharpening to the lowest possible value.

On top of that, the ALL-I image is much more saturated and contrasty, although I used identical picture profiles on both recordings.

ffprobe says that the ALL-I video is 8bit Rec709 4:2:0 with a bitrate of 400Kbit/s.

[Andrew Reid]

Try Standard profile -5 (you dial down the entire profile -5 to some kind of baseline)

Then lift the shadows +2 on the custom curve.

Gives you a good flat profile. Anything else too flat will fall apart.

It's a very good image.

They need to fix the flickering black level though.

[Anaconda_]

@Andrew Reid - I've mostly been shooting Braw with my FP, and never really tested the internal recordings. Do you still recommend those settings, or have you found an alternative? (assuming shooting raw isn't a possibility for various reasons)