Whiteboard glare: what causes it and how to kill it.
Short answer
Whiteboard glare comes from light sources in the board's reflection zone — typically overhead lights directly above you, or a window behind you. Fix: turn off the flash, shift your position 5-15 degrees left or right until the glare blob moves off the writing, and turn off any lights you can directly between yourself and the board.
## Understanding why glare happens
A whiteboard surface — whether matte, semi-gloss, or high-gloss — reflects light sources as visible bright spots. The physics are the same as a mirror: a light source at a certain angle produces a reflection at the equal and opposite angle from the board's surface normal. You're standing at the viewing angle, and when the reflection angle points straight at you, you see glare.
## Diagnosing your specific glare
Before snapping, look at the board with your eyes. Identify where the bright spots are and what's causing them:
- Circular center blob: Usually flash (kill it immediately) or a ceiling light directly above you.
- Horizontal band across the middle: Often a row of overhead fluorescent lights. Moving left or right doesn't help — try backing up and shooting at a slight downward angle.
- Corner or edge blob: Usually a window or lamp to the side. Shift position so you're not in the reflection zone of that source.
## The position fix (works 80% of the time)
- Find the glare blob.
- Step 10 degrees to the left.
- Watch the blob shift across the board.
- Keep moving until the blob exits the writing area — ideally off the board entirely.
- The off-axis angle is usually small enough that VisionKit auto-corrects perspective.
## Controlling the light sources
- Flash: Off. Always. This is non-negotiable.
- Overhead lights: If the room has multiple rows or zones, turn off the row directly above you. Keep the side rows on for even fill light.
- Windows: Close blinds if a window is causing a strong reflection. Or reposition so the window is to your side, not behind you.
- Projectors: If a projector is aimed at the board or the same wall, turn it off before shooting.
## When you can't eliminate all glare
Some rooms don't give you positioning flexibility. In that case, capture the board in two overlapping sections from slightly different angles — each section's glare spot will be in a different place. BoardSnap reads them separately and the AI fills in both perspectives.
## BoardSnap's built-in tolerance
BoardSnap AI reads for meaning, not just pixel values. Moderate glare that doesn't cover complete words or diagrams typically gets read correctly. If a bright spot completely obliterates content, that content is lost — but partial occlusion is usually recoverable.
Frequently asked
Does a matte screen protector help reduce whiteboard glare in photos?
A matte filter on your phone lens would, in theory, scatter the reflected light — but in practice the slight diffusion reduces sharpness noticeably. Repositioning is far more effective and costs nothing.
Can I fix glare in post-processing?
Partially. iOS Photos has Highlights and Brilliance sliders that can recover some blown-out areas. But truly overexposed glare destroys the data — no amount of post-processing can recover content that was completely washed out at capture.
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