The free lighting toolkit

Visual Flash & Ambient Light Playground

Start with your own readings. Calculate the change, verify a frame, and save what works.

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Visual light-balance playground

Move one control and see how flash, ambient and spill change the face and background.

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You’ll get: A visual explanation of what each lighting change does.

Meter direction: dome out → camera. When a tool asks for incident readings, measure at each area with the white dome extended and facing the camera lens.

When should I point toward a light instead?

Exposure / face, chest or background comparison: Dome extended, toward the camera lens at each location. For individual contributions to a combined exposure, keep this method and fire one flash at a time. Then recheck with all lights and ambient included. Match ISO, shutter and meter mode; keep yourself from shading the dome.
Compare individual light sources: For a separate source-contrast test, retract the dome and aim it toward each light from the subject position, following your meter manual. These readings answer a different question: do not mix or add them as camera-facing exposure contributions.
Reflected spot reading: Stand at the camera and aim the spot viewfinder at the surface you want to compare. This does not use the incident dome. Keep spot readings separate from incident readings.

Face f/5.6 → chest f/2 = three stops less measured light. Check both with the final lighting, including spill. Confirm the appearance in a photo; skin and fabric reflect light differently.

See the meter setup and step-by-step check → · Sekonic camera-facing guidance ↗

Start here · what to enter and what to do

You’ll need: Start with the practice values; replace them with readings for your own experiment.

Choose an example, then move just one slider.
Compare face and background. Read the simple plan, then verify it with a meter and photograph.

Example values are for practice. Current means what you measured; goal means what you want. A calculated setting is a starting point to check.

What do these words mean?

One stop: Twice as much light, or half as much. +1 means more; −1 means less.
Camera aperture / meter reading: The camera has one aperture for the whole photo. Meter f-numbers describe light at a location. Face f/5.6 and chest f/2 are three stops apart at the same ISO and measurement conditions.
Key / fill / rim: Your main light / light that opens shadows / light on the subject’s edge.
Isolated reading: Only the named flash contributes. Turn other flashes off and exclude ambient from that flash reading.
Meter tenths: Enter the small extra number on the meter: f/8 plus 3 tenths is 0.3 stop above f/8. Leave 0 if none is shown.
Spill / feather / flag: Unwanted light / turn the beam’s bright center away / block light with a dark card or panel.

Touch a control. Understand the change.

What lights the face? What lights the background?

Explore how main-flash power, shutter time and an optional background flash change both areas. The diagram separates each contribution so spill stays visible.

Enable JavaScript for the interactive experiment. Example readings are teaching values; the model assumes fixed placement and complete flash-pulse capture.

Learn more: examples, explanations & common questions

Use the tool with confidence

See how flash, ambient and spill add together

An interactive teaching model separates the light reaching the face and the background. It uses independent meter readings as an exposure budget, then predicts changes while placement, ISO and flash capture stay fixed.

Choose a practice example and move one slider. Watch both areas, not just the one you want to change.
Read the combined meter targets and compare the background with the face in stops. The source-share bars explain where each area’s light comes from.
For a real shoot, replace every example contribution with a comparable reading. Verify complete-pulse capture, meter the final combination and check a photograph.

Worked example

A face receiving flash f/4 plus ambient f/4 has a combined reading near f/5.6. Reducing ambient by two stops leaves flash f/4 plus ambient f/2, for about f/4.47 total. The subject changes too, even though flash power did not.

Why does the background stop getting darker?

Flash spill remains when you reduce ambient with shutter time. Under complete-pulse capture, shutter does not remove that spill. Change placement or coverage, then remeasure.

Does the preview simulate skin brightness?

No. It shows calculated incident-light contributions and relative levels, not rendered pixels, material reflectance or a realistic portrait.

Can I use it for HSS or very short global-shutter exposures?

Its shutter slider assumes the entire flash pulse is captured unchanged. Use actual camera tests and an appropriate metering method when that assumption does not hold.

Subject & Background Lighting Ratio Calculator →Flash & Ambient Coach: Darker Sky, Balanced Portraits →Flash Power Calculator from a Meter Reading →Flash Light Spill Mapper & Power Solver →

Learn the decision behind the setting.

Learn Off-Camera Flash: A Simple One-Light Practice Path

By Dwayne of DNA Premium Portraits, Sacramento-area portrait photographer. See formulas, assumptions and equipment sources.

Save the setup, then bring it into your on-set field card →

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Built for intentional light by DNA Premium Portraits ↗ · Methods & assumptions · My saved setups