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Viewing Angles



At night or in indoor locations not facing daylight sun, most LED's will give nearly 120 viewing. In addition, during daytime under direct sunlight, basic Ultra bright LED's (e.g. our model no. UB415) will give 60 viewing. More advanced wider angle ultra bright LED's will achieve 70 under sunshine.
 

Viewing Distance

The chart below gives the height of character required for a particular viewing distance. This is approximate as you should also take into account ambient light levels (e.g. bright day or night) and the brightness of the LED used in the sign.

Character

 Height (cm)

Character

 Height (inch)

Reading 
Distance (m)

Reading 
Distance (m)

3 1.18 18 59
5 1.97 30 98
10 3.94 60 197
18 7.09 108 354
22 8.66 132 433
44 17.32 264 866
66 25.98 396 1299
100 39.37 600 1969
200 78.74 1200 3937

Millicandela (mcd)

This is a unit of measurement of brightness for a single LED. Anything less then 300mcd is not adequate for use under sunlight.

Standard red (e.g. model no. 215 R) 20-50 mcd
Multi-color (e.g. model no. Big Dot) 200-250 mcd
Ultra-bright (e.g. model no. MegaStar) 1000 mcd

NIT

This is a unit of measurement  normally used to describe the brightness on bigger signs. It is defined as candela per square meter. It is calculated as (candela per pixel) x (no. of pixels per square meter).

For example, MegaStar 200/4  using 1000 mcd mono-color LED's It's brightness is:


(1.0 x 64 x 32) / 0.5 m2 = 4096 NIT.

 

 

Viewing Distance

Sign readership for various character heights at different speeds

Character Height in Inches

Reading Distance

 in Feet

Viewing Exposure in Seconds

20 MPH

(29.3 ft/sec)

30 MPH

(44.0 ft/sec)

40 MPH

(58.7 ft/sec)

50MPH 

(73.3 ft/sec)

60 MPH

(88.0 ft/sec)

18 900 30.7 20.5 15.3 12.3 10.2
24 1200 41.0 27.3 20.4 16.4 13.6
30 1500 51.2 34.1 25.6 20.5 17.0
36 1800 61.4 40.9 30.7 24.5 20.5
42 2100 71.7 47.7 35.7 28.6 23.9
48 2400 81.9 54.5 40.0 32.7 27.3
60 3000 102.4 68.2 51.1 40.9 34.1

 

Footnotes:

  1. The general rule of 50 feet of distance for each inch of character height was developed for 3M Co. by Dr. Lauer in a series of studies 25-30 years ago. If the sign is directly in view, the distance applies. If there is considerable set-back from the road, the distance would be the hypotenuse.
  2. The feet traveled per second is indicated in the parenthesis.
  3. The data in the 3-7 columns is viewing exposure in seconds for moving vehicles.


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