Optical filter designed to block ultraviolet and infrared wavelengths from reaching digital camera sensors – prevents color casts, false colors in black fabrics, and focus shifts that occur when sensors detect light outside the visible spectrum that film stock naturally rejected.
What is a UVIR Filter?
A UVIR filter blocks ultraviolet and infrared light from reaching digital sensors. While film naturally ignored these wavelengths, digital sensors can capture them – leading to color issues.
Basic Principle
| Aspect | Description |
|---|---|
| Definition | UV+IR blocking filter |
| Function | Spectral filtering |
| Problem | Sensor IR/UV sensitivity |
| Solution | Wavelength blocking |
Why Digital is Different
| Aspect | Film | Digital |
|---|---|---|
| UV | Naturally blocked | Sensitive |
| IR | Not sensitive | Highly sensitive |
| Correction | Not needed | Filter required |
| Effect | Natural colors | Potential discoloration |
IR Issues
| Symptom | Cause |
|---|---|
| Magenta casts | Black appears discolored |
| Skin tones | Unnaturally warm |
| Focus shift | IR focuses differently |
| Contrast | Reduced |
UV Issues
| Symptom | Cause |
|---|---|
| Haze | Atmospheric UV |
| Blue cast | UV excess |
| Blurriness | UV diffraction |
| Skin detail | Overemphasized |
Filter Construction
| Type | Technology |
|---|---|
| Absorptive | Glass absorbs |
| Reflective | Hot Mirror |
| Dichroic | Wavelength-selective |
| Hybrid | Combined |
Use Cases
| Situation | Necessity |
|---|---|
| Daylight | High |
| With ND | Very high |
| Tungsten | Low |
| Mixed | Medium |
ND Combination
| ND Type | IR Behavior |
|---|---|
| Standard Glass | Lets IR through |
| IRND | Blocks IR |
| Variable ND | Often IR problematic |
| Internal ND | Camera-dependent |
Integrated Solutions
| Camera Type | UVIR Handling |
|---|---|
| Cinema | Often OLPF integrated |
| DSLR | Mostly weaker |
| Mirrorless | Varies |
| Action | Minimal |
External Options
| Position | Variant |
|---|---|
| Matte Box | Standard 4x5.65 |
| Screw-on | Lens filter |
| Rear Filter | Behind lens |
| Sensor Filter | In-camera |
Manufacturers
| Brand | Products |
|---|---|
| Tiffen | T1 IR |
| Schneider | IR/UV Cut |
| Formatt | Firecrest IRND |
| NiSi | Cinema IR Cut |
Specifications
| Parameter | Typical |
|---|---|
| UV Cutoff | 380-400nm |
| IR Cutoff | 680-720nm |
| VL Transmission | 90%+ |
| Color Shift | Minimal |
Quality Differences
| Factor | Impact |
|---|---|
| Coating | Reflections |
| Glass | Optical quality |
| Cutoff | Sharpness of separation |
| Neutrality | Color shift |
Workflow
| Phase | Activity |
|---|---|
| Prep | Test filters |
| Shoot | Use situationally |
| Monitor | Observe colors |
| Post | Minimal needed |
Troubleshooting
| Problem | Solution |
|---|---|
| Still IR | Stronger filter |
| Color cast | Check filter quality |
| Vignetting | Thinner filter |
| Reflections | Coating quality |
Best Practices
| Practice | Reason |
|---|---|
| Always test | Camera setup |
| Document | Filter configuration |
| Consistency | Across production |
| Backup | Spare filters |
Today
UVIR filters are a standard tool in digital cinematography. With increasing sensor sensitivity and higher resolutions, IR issues become more visible. Combined IRND filters simplify the workflow, while dedicated UVIR filters offer maximum control. The right choice depends on the camera, lighting situation, and workflow.