Resources
Convex Safety Mirror Sizing — Viewing Distance to Dome Diameter
Buying a convex mirror is a sizing problem, not a style problem. Distance drives diameter; the mounting position drives the dome type.
Short answer: two things decide the specification — how far the observer stands from the mirror, and where the mirror mounts. Longer viewing distances call for a larger diameter; the mounting position decides the dome type, with full domes suiting four-way intersections, quarter domes suiting ceiling corners and half domes suiting T-junctions or aisle ends.
Sizing by viewing distance
A convex mirror trades image size for field of view. Going bigger does not magnify — it extends the usable distance at which a person can still read what they are seeing. That is why distance, not room size, is the input.
| Mounting position | Dome type | Common application |
|---|---|---|
| Ceiling over a four-way crossing | Full dome | Warehouse aisle intersections |
| Ceiling corner | Quarter dome | Corridor turns, small rooms |
| Wall at a T-junction or aisle end | Half dome | Aisle ends, loading bays |
Diameter follows the viewing distance rather than the room size, and the only reliable way to fix it is on site: a forklift driver in poor light needs more mirror than a pedestrian at the same distance under good lighting. Stand at the observation point with a sample before committing to a hundred units, and tell us the distances so we can suggest sizes against your actual sightlines.
Dome type follows the mounting position
- Full dome covers four directions from a ceiling mount, which suits an intersection of two aisles.
- Half dome covers 180 degrees, which is what a T-junction or the end of a single aisle actually needs; a full dome there wastes half its surface on a wall.
- Quarter dome mounts in a ceiling corner and covers the two directions that matter there. Our ceiling corner quarter-dome security mirror is built for that position.
Buying full domes for every position is the most common over-specification in this category. It costs more and, at a T-junction, delivers no additional coverage.
Indoor and outdoor are different products
Outdoor units face UV, temperature swing and rain, which changes the backing, the housing and the mounting hardware. An indoor unit used outside is working outside what it was built for, and weathering usually shows up long after anyone connects it to the purchase decision.
Our 800 mm car park convex safety mirror is the outdoor build; the 600 mm warehouse convex safety mirror is the indoor one. Specify the environment, not just the diameter.
What actually gets these installed wrong
- Mounted too high. A mirror above the useful sightline shows ceiling. Set the height from where the observer's eyes are, not from a standard fixing height.
- Mounted flat to the wall. Convex mirrors need to be angled at the approach, and the bracket has to allow that adjustment after installation.
- One mirror asked to do two jobs. Two approaches at different distances usually need two mirrors, not one larger one.
Ordering
Convex mirrors are the part of the catalogue where the buyer is almost always a facilities or safety function rather than a designer, so the specification is short and the quantities repeat. Minimum order is one piece, and mixed containers across the range are normal.
Send the observation distances and the mounting positions from the ADA, convex and safety-backed range, and we will come back with sizes and a price within 24 hours.