#apertus IRC Channel Logs

off to bed now ... have a good one everyone!

irieger: interesting link, thanks

morning Bertl :)

not that I'd know of, why?

https://youtu.be/izDzFov3nDM?t=208

it doesn't look like youtube compression

also a few frames later there's some even more weird stuff

you probably want to check with the raw data and/or se6astian|away when he wakes up

couple of sample frames for se6astian : https://goo.gl/photos/QYggaXmfiQzKZpUK9 https://goo.gl/photos/zrMwj77c53dJVAft9

Emulsion film?

Bertl: yep, also some strong colour correction (for effect rather than correcting for sensor issues)

which could be misleading

yep

I've had a quick look at the DNG files and they look neutral except for the pink highlights

colored highlights might be due to near IR or just the sensor profile (I presume the raw data is within the 12bit range)

have cmosis given an explanation for the artefacts on the right?

ah

we will shortly test with the engineering sample we used on the alpha, to figure out if it is caused by the new sensors (v2) only

troy_s mentioned that the pink highlights was a known issue and this data would probably have to be clipped/ignored?

(on the RAW software converter)

istr that normally that data is ignored when outputting JPEGs or when converting RAW with highlight recovery disabled

"proper" raw data should not reach the lowest and highest values on each channel (for 12bit that is 0 and 4095)

otherwise the offset or gain is set wrong and clipping is to be expected

yes, that's a good example, on the left, you see that neither black nor white is reached

(I'm talking about confettiTV-32.raw12, which appears to be from the same movie as intracube's link)

alexML: ah yep. I noticed the crushed blacks. I was expecting to see FPN and sensor noise in the darkest parts of the frame

yes, it's clipped

I noticed similar black clipping on some of the footage from the alpha camera

i.e. either with the sensor registers or with the linearization lut, instead of the matrix or gamma lut (where it should happen)

I

alexML: what experiments do you do with fpn reduction?

nevertheless, more testing needs to be done

irieger: I'm trying to find a way to estimate the FPN from any real-world image, since the optical black areas are way too small on this sensor

Real world data? How about images of black? ;-)

:P dark frames are very easy to fix, I already analyzed them in this thread: http://www.magiclantern.fm/forum/index.php?topic=11787

Thanks for ML btw. You are the reason I switched to Canon with their inferior sensor instead of Nikon when I jumped to Sony ship when it was clear they wouldn't make any more DSLRs ...

highlight recovery + neutral grade test: https://www.youtube.com/watch?v=GTQzGedoxrc

The transform should maintain some possible negative values for sensor noise.

intracube: Remember too (not that I know anything about the Beta, as I haven't worked on it yet) that the linear portion of the sensor doesn't carry through the full range of data (hence why when doing HDR merges software keeps a solid anchor in the linear portion). Any colour transform has to take this into account and nonlinearly adjust the data (hence 3D

intracube: Most transforms vendors use are strictly a matrix, which is 'good enough'. A proper colorimetric transform for post production would ideally hold the proper XYZ values across the full range of data, and as a result, be a nonlinear transformation to avoid that colour casting you are seeing near the highlights. Hello rat piss yellow.