Alexa Mini LF VFX-Metadata (focal length + tilt/roll)

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soulcage
Posts: 1
Joined: Mon Jun 15, 2020 9:52 am

hi,

in an upcoming project, a mini LF will be involved, and i want to make use of the metadata, especially for vfx.
to setup a vfx workflow, i downloaded a sample footage (arriraw, the one with the sheeps and the zoom, F004C028_190925_MN99.mxf) from the arri-website, to check the metadata. the sample footage only contains focal length, no tilt/roll...

- is the mini LF capable of recording the tilt and roll?
-the focal length seems to be inverted in the sample footage's metadata. it goes from 70mm to 200mm, but visually it is a reversed zoom (from 200mm to 70mm). is this a failure in the metadata?
Jan Heugel
Posts: 516
Joined: Wed Aug 13, 2014 3:15 pm
Location: Munich, Germany
Contact:

Dear Willi,

in regards to tilt and roll:

Here's the excerpt from our ALEXA Mini LF FAQ
Export laws dictate that for sensors made up of more than a certain number of photo sites, we cannot record positional information like tilt and roll, lest the camera be classified as military equipment. While the photo site count of the Super 35 ALEXA, ALEXA Mini and AMIRA cameras fall below this boundary, the ALEXA LF and ALEXA Mini LF are above it. However, we can display the tilt and roll information as well as the digital bubble level.
As for the metadata of that clip...
You are the first mentioning that - I'll look into it. For now, I can blame the beta firmware which might have inverted the scale.
F004C028_200mm.jpg
F004C028_70mm.jpg
Cheers,
Jan
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Jan Heugel
Application Engineer
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