STILL GENTLY PRODDING THE ANCIENT HORSE - SI2K.

[Robert Hart]

For sake of curiosity, some folk might be slightly interested in some things I have been doing in an attempt to hot up the SI2K. An approved choice for shooting with the SI2K was for the combined OPLF and IR filter to be replaced by a simple IR filter when chasing that little more apparent resolution.

One of the elements of the secret sauce of the ARRI Alexa, as well as its unique sensor was alleged to have been a small contrast filter panel close to the sensor to extend the apparent dynamic range. So I have gone there. A few years ago, Formatt Hitech had the generosity to supply me with some small cut panels of NC8 filter material to experiment with. When I want some more filters, they will get my business.

After a four year period and a dalliance with a pre-owned ( am I allowed to say battle-tested ) Blackmagic "big" URSA, I have returned to the SI2K. The big URSA martyred itself beyond economic repair over 4 months of winter storage.

Whilst the accompanying image is in no way definitive of any improvement imagined or real, an ARRI lineage by proxy might be assumed. The SI2K recorder unit and hardware was built by ex ARRI engineers. The ARRI Log to Rec709 3D LUT in DaVinci Resolve 15 works almost perfectly on images exposed correctly for the default AKA Rec709 Iridas look from the SI2K. Resolve's flavour of the cineform decoder does not interpret the .look files.

Whether the contrast filter does increase the apparent dynamic range may be wishful thinking on my part. The flat RAW RGB parade seems to have slightly more space above and below in the display frame of Premiere Pro with the filter in place. A piece of NC8 contrast filter rearside of the OPLF/IR filter in the older RED cameras might be a worthwhile experiment.

Use of a full 4x4 or 4x5 filter in a mattebox in front of the lens may give an indication of what to expect. This mage may not be the sharpest kid on the block but the greens come up nicely with the ARRI LUT applied in Resolve.

SI2K.
Voigtlander-for-Nikon 40mm f2 lens.
Metabones Speedbooster for BMPCC modified to IMS-Mount.
No OPLF.
IR filter near sensor.
Formatt Hitech NC8 filter panel added close to sensor.
-3db video gain.
Exposed to suit default look. ( Rec709 ).
Shutter 1/100th sec.
ARRI LOG to Rec709 3D LUT added in DaVinci Resolve.
No other grading.
Exported to H264.
Opened in Premiere Pro CS6 and frame exported.

I am a bit witless when it comes to the internet and embedding images so you will have to click on it yourself to make it stick its head up.

 

[Dan Kanes]

gorgeous image - both in texture and color. I bet this would look great on human faces.

Keep prodding that horse! Just don't try milking it!

 

[Marcus Friedlander]

Very cool! Would love to see more shots!

 

[Robert Hart]

As for faces and skin detail, I have one shot. The subject did not want the image to be publicly propagated so I will have to shoot more and post that footage. At -3db, the colour saturation is rich but one can singe the whites a bit unless due care is taken. In 4pm sun from the side, I exposed the brightest side of the person's face almost on the threshold of burnout and the shadow detail still came up nicely. Grading off the raw image would leave some more room to move. When you are using wide lenses, you do miss that fine 4K texture once you have had a taste of it but with care, the SI2K can still make a decent film. Whether anyone would want to invest good production values and not value-add with 4K+ of resolution and better than 11 stops of dynamic range is another matter.

 

[L. Langer]

This makes me want to see what can be achieved with the last remaining DALSA Origin-series cameras and today's workflow tech and processes. The one film I know of shot on Origin - Reach For Me - was (apparently) the first feature-length digital video film to be fully finished in 4K, but it has never gotten a proper release on disc or VOD, so I'd love to see it re-finished with today's standards of post-production and HDR grading.

 

[Robert Hart]

L. Langer.

Sadly some prosper and some fade away. There were a few of the P+S Technik designed/built optical viewfinders for the Dalsa turned up on eBay for a while after the Dalsa camera become unloved by a move of the business in a new direction. I bought one, principally for the eyepiece which has the traditional iris intended originally to protect film but also now protects the sensitive organic LCD panel inside the finder from focused sunlight.

If the generations of RED camera sensors had not been such deep-set beasts, the viewfinder would have been an ideal companion as it was already capable of viewing a Super35mm film image frame.

When feature movie post work changed to digital intermediate and scanned negatives, along with "cold arc" film projection lamps, the film experience entered a decline for me. Digital projection has got better but it still depends upon the financial return the cinema owner can achieve to afford fixing image reproducers which have patches of dull off-colour pixels down in the right corner and multichannel sound being out of whack.