Cinematographer
Lens Prep ist eine meiner wichtigsten Prep-Sessions. Hier lerne ich die Charakteristik meiner Objektive kennen – Schärfe, Flare, Breathing. Probleme hier finden, nicht am Set.
The systematic testing, inspection, and preparation of camera lenses before a film production – includes checking optical quality, focus accuracy, iris function, mechanical condition, compatibility with camera systems, and documenting characteristics to ensure reliable performance during shooting.
What is Lens Prep?
Lens Prep (Lens Preparation) is the systematic testing and inspection of all lenses before production begins. The process ensures that all optics function perfectly, both optically and mechanically, and are compatible with the camera system.
Basic Principle
| Aspect | Description |
|---|---|
| Purpose | Quality Assurance |
| Timing | Before Shooting Starts |
| Location | Rental House/Studio |
| Involved Parties | DoP, 1st AC, Rental Tech |
Areas of Inspection
| Area | Inspection |
|---|---|
| Optical | Image Quality |
| Mechanical | Functionality |
| Compatibility | With Camera |
| Documentation | All Data |
Optical Tests
| Test | Description |
|---|---|
| Sharpness | Check Resolution |
| Contrast | Micro-contrast |
| Flare | Behavior Against Light |
| Vignetting | Edge Darkening |
Sharpness Test
| Method | Description |
|---|---|
| Test Chart | Siemens Star, Resolution Chart |
| Focus Check | At All Focal Lengths |
| Aperture | Wide Open to Closed |
| Distance | Various Distances |
Focus Breathing
| Aspect | Inspection |
|---|---|
| What | Field of View Change When Focusing |
| Why | Disrupts Focus Pulling |
| How | Rack Focus, Observe |
| Documentation | Degree of Breathing |
Mechanical Inspection
| Element | Check |
|---|---|
| Focus Ring | Smoothness |
| Aperture Ring | Clicks, Detents |
| Zoom | Smoothness |
| Mount | Secure, No Play |
Focus Ring Test
| Property | Inspection |
|---|---|
| Smoothness | Smooth Without Resistance |
| Backlash | No Play |
| Markings | Accurate |
| End Stops | Functional |
Compatibility Check
| Element | Inspection |
|---|---|
| Mount | Fits Camera |
| Communication | Electronics Function |
| Clearance | No Sensor Contact |
| Coverage | For Sensor Format |
Matte Box and Filters
| Test | Description |
|---|---|
| Fit | Lenses Fit |
| Filter Compatibility | Sizes Match |
| No Vignetting | At All Focal Lengths |
| Follow Focus | Gear Fits |
Follow Focus Setup
| Element | Check |
|---|---|
| Gears | Fit Focus Ring |
| Markings | Transfer Correctly |
| Motor | For Motorized FF |
| Handwheel | Smooth |
Documentation
| Data | Record |
|---|---|
| Serial Numbers | Of All Lenses |
| Focal Lengths | Available |
| Special Characteristics | Individual Features |
| Problems | Note All |
Lens Chart/Lens Map
| Information | Record |
|---|---|
| T-Stop Range | Min/Max |
| Close Focus | Minimum Distance |
| Filter Size | Diameter |
| Weight | For Stabilizer |
Insurance and Handover
| Aspect | Handling |
|---|---|
| Condition Report | Document Condition |
| Photos | Upon Handover |
| Signatures | Handover Protocol |
| Insurance | Confirmation |
Test Footage
| Purpose | Description |
|---|---|
| Reference | For Color Grade |
| Look Decision | DoP/Director |
| Comparison | Between Lenses |
| Documentation | For Post-Production |
Sensor Test
| Inspection | Description |
|---|---|
| Back Focus | Correct Focal Plane |
| Shim | Adjust if Necessary |
| Calibration | With Camera |
| Verification | After Adjustment |
Typical Prep Workflow
| Step | Activity |
|---|---|
| 1 | Receive Equipment |
| 2 | Visual Check |
| 3 | Assembly and Testing |
| 4 | Documentation |
Scheduling
| Scope | Duration |
|---|---|
| Prime Set | 4-8 Hours |
| With Zooms | 1 Day+ |
| Complex | 2+ Days |
| Vintage/Special | Extra Time |
Rental House Support
| Service | Description |
|---|---|
| Technicians | Support |
| Equipment | Test Charts, Monitors |
| Repair | On-Site Possible |
| Exchange | For Issues |
Common Problems
| Problem | Solution |
|---|---|
| Decentering | Exchange Lens |
| Stiff Ring | Cleaning/Exchange |
| Back Focus Error | Shimming |
| Internal Dust | Cleaning/Exchange |
Best Practices
| Practice | Reason |
|---|---|
| Sufficient Time | Test Thoroughly |
| Document Everything | For Reference |
| Involve DoP | Creative Decisions |
| Backup Options | In Case of Issues |
Today
Lens Prep is an indispensable part of professional film production. The systematic testing of all lenses before shooting begins prevents surprises on set. From optical quality to mechanical function – thorough prep gives the camera crew confidence and enables seamless work during production.
From the crafts
Perspectives
Director
Während der Lens Prep sehe ich erste Tests unserer Optiken. Der DoP kann mir zeigen, wie der Look aussehen wird – wichtig für kreative Entscheidungen.
Producer
Lens Prep ist Zeit und Geld gut investiert. Probleme mit Objektiven am Set zu entdecken kostet Drehtage. Ein gründlicher Prep verhindert das.
More in the lexikon
Related terms
Test your knowledge
Quiz
1. Zu welchem Department gehört „Objektiv-Prep / Objektivvorbereitung / Objektiv-Test"?
2. Wie viele verschiedene Fachperspektiven bietet dieser Eintrag?