Optical filter that blocks both ultraviolet and infrared light while transmitting visible wavelengths – essential for digital cinema cameras to prevent color contamination, false colors, and focus issues caused by UV and IR light that digital sensors can detect but human eyes cannot.
What is a UVIR Cut Filter?
A UVIR Cut Filter blocks ultraviolet and infrared light while allowing visible wavelengths to pass. It is essential for digital cinema cameras to prevent color distortion caused by UV and IR radiation that sensors can capture.
Basic Principle
| Aspect | Description |
|---|---|
| Definition | UV+IR Blocking Filter |
| Function | Wavelength Selection |
| Blocks | UV (<380nm), IR (>700nm) |
| Transmits | Visible Light |
Why Necessary?
| Problem | Cause |
|---|---|
| IR Contamination | Sensor Sensitivity |
| False Colors | IR in Visible Spectrum |
| Focus Shift | IR Focuses Differently |
| UV Haze | Atmospheric UV |
IR Contamination
| Symptom | Appearance |
|---|---|
| Black Fabrics | Magenta/Brown |
| Skin Tones | Discolored |
| Highlights | Color Cast |
| Focus | Soft |
Affected Situations
| Situation | Risk |
|---|---|
| Strong ND | High |
| Sunlight | Medium-High |
| Tungsten | Low |
| LED | Variable |
Filter Types
| Type | Characteristic |
|---|---|
| Hot Mirror | Reflective |
| Absorptive | Absorbing |
| Hybrid | Combined |
| Internal | Camera Integrated |
Internal vs. External
| Position | Pros/Cons |
|---|---|
| Internal (OLPF) | Always Active, Limited |
| Internal (Slot) | Flexible, Modifiable |
| External (Matte Box) | Swappable |
| Lens Mount | Permanent |
Camera-Specific
| Camera | UVIR Situation |
|---|---|
| ARRI | Internal OLPF |
| RED | Filter System |
| Sony Venice | OLPF + Slot |
| Blackmagic | Varies |
ND Combination
| ND Type | UVIR Requirement |
|---|---|
| No ND | Often Minimal |
| Variable ND | High |
| Glass ND | Depending on Type |
| Built-in ND | Camera Dependent |
Manufacturers
| Brand | Product |
|---|---|
| Tiffen | T1 IR Filter |
| Schneider | Platinum IRND |
| Formatt Hitech | Firecrest |
| ARRI | FSND (incl. IR) |
Specifications
| Parameter | Typical |
|---|---|
| UV Cutoff | ~380nm |
| IR Cutoff | ~700nm |
| Transmission | 90%+ Visible |
| Density | Neutral |
Performing Tests
| Test Method | Description |
|---|---|
| Black Fabric | Shoot black fabric |
| IR Remote | LED visibility |
| Chart | Color reproduction |
| A/B Comparison | With/without filter |
Workflow
| Step | Activity |
|---|---|
| Prep | Test equipment |
| On-Set | Use as needed |
| Monitor | Observe colors |
| Adjust | Situationally |
Combinations
| Filter Stack | Consideration |
|---|---|
| UVIR + ND | Common |
| UVIR + Polarizer | Possible |
| UVIR + Diffusion | Order |
| Multiple | Vignetting |
Challenges
| Problem | Solution |
|---|---|
| Reflections | Coating Quality |
| Vignetting | Thin Filters |
| Cost | Budget Planning |
| Consistency | Matching |
Best Practices
| Practice | Reason |
|---|---|
| Test | Before Production |
| Document | Filter Configuration |
| Backup | Spare Filters |
| Consistency | Throughout Shoot |
Today
UVIR Cut Filters are standard equipment for digital cinematography. With the increasing sensitivity of modern sensors and the prevalence of strong ND filters, IR control is more important than ever. Integration into combined IRND filters has simplified workflows, while separate UVIR cuts offer maximum flexibility.