Kodak Vision 3 film VS. Canon 7D w/CineStyle ad hoc test

Alex Walker guest blogger shares with us an ad hoc test comparing the Canon 7D w/CineStyle
to Kodak Vision 3 film.

He details for us his workflow (found below the video) including what he did in his transcoding and
color correction pipeline.

By Alex Walker:

Kodak Vision 3 film vs. Canon 7D w/CineStyle ad hoc test

Cinematographer Michael Street recently brought me on board for a 35mm short film project of his.
During our camera prep I did my best to match each of Street’s shots with my 7D.

Completely ad hoc; no tripod for the 7D and I didn’t match glass. My goal was to push the smaller
digital format to its max and see how close I could get to the 13.5-14 stops of latitude that Vision 3
is known for.

Overall, I’m extremely pleased with the results.

I had my 7D set to AdobeRGB. When bringing the media off the cards I transcoded it all to Avid DNxHD 175x
and labeled the input media as RGB. I create my DNxHD175x media using Adobe media encoder CS5.5.

Word down the line is that Adobe collaborated with Canon on their proprietary h.264 interpretation algorithm.
I’ve done some comparisons and to my eye the Adobe created media looks better.

More info on that in my article here: How to use Adobe’s extra DSLR color info in Avid MC5/FCP 

Since Avid works in a rec709 space it will squeeze the 0-255 range down to 16-235 broadcast legal.
The already flat cinestyle footage looks even more flat on your RGB monitor.

When exporting for the web I select 601/709 to tell it my corrections are broadcast legal and it will take the
illegal color ranges and export them as a full RGB video.

Just using the color correction mode in Avid MC I was able to get really close to the look of the 35mm shots.

I started off by adjusting the master curves to bring the shadows down to match the level seen
on film. I really didn’t touch the highlights.

Boost the saturation up about 150%, then use the RGB curves and the 3-up corrector to match the
different hues. Vision 3 seemed to have very blue-green shadows naturally so I applied that globally. 

Of course there was no way around the global shutter causing motion rendering issues or the line
skipping aliasing on the finer details but in terms of latitude, the 7D did well.

It really just depends on what you’re shooting. Most of these shots have relatively small contrast ratios.
However take a look at the difference between the 2 shots of the warm light in the middle of the video.

As you can see the 7D material has a very hard fall off from the outside of the light toward the center
where it goes past 100IRE. Film’s negative process still holds the detail in the light all the way through.

So keep this in mind when you light your sets. Know that your 7D will only be able to push 10-11.5 stops.
Treat it like reversal film.

Keep your ratios small, watch aliasing, and minimize rolling shutter issues by moving the camera in
slower, calculated ways. Vision 3 tends to crush the shadows a tiny bit. Shoot a 1/4 hot to keep them.

DON’T do this with digital. In fact, you should NEVER shoot over with digital as an over exposed digital
image cannot be brought back like film.

It is recommended that you rate your camera lower if anything so that you build in an under exposure
to save your highlights. 

http://www.alexwalkerstudios.com
@awalker47

- Alex Walker
Director of Photography