The Blackmagic Design Spares - Camera URSA Mini Pro - OLP Filter 12K is a specialized optical component designed specifically for the URSA Mini Pro 12K and 12K OLPF models. This is a high-performance Optical Low Pass Filter (OLPF) that sits directly in front of the 12.2MP sensor.
Because the 12K sensor features a unique non-Bayer RGB mapping (with equal parts Red, Green, and Blue pixels), this filter is tuned specifically to manage the extreme resolution and color science of that sensor.
Functional Role
The OLPF is a critical gatekeeper for image quality:
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Moiré & Aliasing Reduction: Its primary job is to slightly blur the image at a microscopic level to prevent "shimmering" or "rainbow" patterns when filming fine details like fabric, hair, or distant architecture.
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IR Cut Filtration: It blocks Infrared (IR) light from reaching the sensor, which prevents the "magenta shift" common in digital sensors when using heavy ND filtration.
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Sensor Protection: It acts as the final physical barrier protecting the 12K sensor from dust, moisture, and accidental contact during lens changes.
When to Replace the 12K OLPF
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Permanent Image Artifacts: Scratches or pits on the glass that appear as soft, unmoving spots in your footage (most visible at narrow apertures like $f/16$ or $f/22$).
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Coating Delamination: In high-humidity environments, the specialized IR-cut coatings can sometimes "bubble" or peel, leading to localized color shifts or haziness.
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Physical Cracking: Direct impact damage or extreme thermal shock.
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Internal Contamination: If fungus or oil develops between the OLPF and the actual sensor glass, the OLPF must be removed to facilitate cleaning or replacement.
Key Features
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12K Optimized: Unlike the OLPFs for the 4.6K G2 or the original URSA, this glass is specifically calibrated for the $80\text{MP}$ data throughput and color geometry of the 12K sensor.
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Gen 5 Color Science: Specifically coated to maintain the skin tones and highlight roll-off characteristic of Blackmagic’s Generation 5 color science.
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Precision Fitting: Designed to seat perfectly within the URSA Mini Pro’s sensor mount, ensuring an airtight seal to prevent "dust donuts."
Technical Installation Note
DANGER: Level 4 (Expert) Repair. This is the most sensitive mechanical repair you can perform on an URSA.
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The "Clean Room" Requirement: You should only attempt this in a controlled environment. Any dust trapped behind the OLPF during installation will be permanently visible on your footage and is extremely difficult to remove without damaging the sensor underneath.
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Shimming & Flange Focal Distance: The OLPF has a specific refractive index and thickness. Replacing it can occasionally shift your flange focal distance slightly. You may need to re-shim your PL or EF mount after installation to ensure your lens distance scales remain accurate.
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Gasket Integrity: The OLPF is held in place by a precision rubber gasket. If this gasket is misaligned, the glass will not sit flat, leading to "soft corners" in your image.
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No Chemicals: Never use harsh chemicals to clean the underside of the new filter. A dry, static-free air puffer is the only recommended tool for the internal-facing side.
Expert Advice: If you are seeing spots, try a wet-clean with a specialized sensor swab and $99\%$ isopropyl-based sensor fluid first. Many "scratches" are actually just dried mineral deposits from moisture that a standard blower won't move. If the mark remains after a professional wet-clean, then the glass is physically damaged and needs replacement.
Are you noticing a permanent mark on your 12K footage, or has the filter physically cracked due to an impact?
