Contrast
I’ve always had a hate/hate relationship with the “contrast” slider – no matter which software. It would always clip the shadows, or worse, create negative values if used on floating point data (less of an issue in Photoshop but easily observable in Fusion). It looked ugly and I’ve spent a lot of redoing other people’s grading nodes because the color values were broken all over the place.
If you don’t know it already, here’s what the contrast slider usually does:
contrast as found in most image editing software
If you color-correct in sRGB (yuck) the slider really does change the picture’s contrast. But like I said, it clips shadow details pretty quickly. Which translates to “instantaneous” in linear (non-gamma-corrected) space where color values are tiny. The better way to increase contrast was an S-shaped curve tool (recently, Photoshop has finally improved its contrast algorithm and labeled the formula it used before as “legacy”).
Nuke also has a contrast slider in its color correction node. First I avoided it like the plague until I tried it on a test gradient to figure out what it does. Lo and behold, it’s actually usable since its formula has been re-invented for linear floating point pipelines. It is actually a gamma correction but instead of “pivoting” around a value of 1.0 it is anchored on 0.18 – neutral gray in linear space:
contrast as implemented in Nuke (on a scale from 0.0 to 1.0)
The formula is easy to implement: pow(color / 0.18, contrast_value) * 0.18
Of course it needs a failsafe when contrast_value is zero, but this is obviously a constant value of 0.18.
I have built this formula into a Fuse for Fusion along with Nuke’s other color correction sliders. This makes the tool useful to copy color corrections made in a Nuke script to Fusion. It could have been a macro, but the Fuse API allowed me to play around with the GUI and make Nuke users feel even more at home – myself included.
Download and more info at Vfxpedia.
Postcards from Spain
Pinxtos - When Tapas meet Sushi 🙂
View from a hotel room in Sitges
Street Corner in Valencia
Palau de les Arts Reina Sofia
House front in Barcelona
All these photos – except for the Pinxtos – were shot as an exposure stack, aligned in Hugin and fused using enfuse. Subsequent editing in Photoshop.
Bildfehler update
I finally managed to update my portfolio site at www.bildfehler.de with some stuff I did in the past 12 months. It’s in German but it’s got little text anyways. Check it out 🙂
Unfortunately I can’t show any imagery from my involvements on Ninja Assassin and Polanski’s Ghostwriter. Instead, there’s two new commercials, one for Mingr (posted previously on my blog) and a full CG car commercial for Infiniti:
And finally some frames from my main Shanghai project, a 10 minute motion ride for General Motor’s EXPO pavilion. It was shot on RED for the 4K horizontal resolution and featured lots of full-CG panoramas of a future version of Shanghai as well as lots of integration of greenscreen people into CG cars. I was involved in setting up the pipeline, leading an international comp team and developing the warm look of the CG scenes. Compositing was done in Nuke. It involved heavy use of projections to fit people into CG camera moves that went further and further away from what was shot. Also, mimicking real-life lens-flares was a fun task 🙂
Thanks to all people involved! One of our shading artists, Markus Graf, has posted a short reel of final as well as not-so-final scenes on YouTube:
http://www.youtube.com/watch?v=foZTMbYF4zE
Inception
In other news, I had this weird dream in which Mick Jagger broke into my house to reclaim a painting that I had previously stolen from him. Upon catching him in the act he asked me to do some VFX shots for the movie version of his heist which would have required a CGI replacement of his head except for his lower jaw which was to be shot in front of greenscreen.
I have difficulties piecing together the images that were mashed up by my subconciousness, but this awesome dialogue reminiscent of Clients From Hell probably played some part in it:
And if one day Mick Jagger is in a movie like this remember: you’ve read about the plot here first 🙂
