Topcon Optical Instrument Comparison

Westar carries a full line of Topcon optical instruments. If you need to measure light, we can help you select which Topcon photometer, colorimeter, spectroradiometer, color video photometer, or response detector is right for your application.

Specifications SR Series BM Series
Optical System SR-LEDH SR-LEDW
SR-LEDW-5N
SR-UL2
SR-UL2s
SR-UL1R SR-3AR BM-5AC BM-7AS BM-9A
Objective Lens f=82mm F2.5 f=82mm F2.5 f=80mm F2.5 f=36mm F2.5
Eyepiece Lens Collimating lens:
View field 5°
View field 5°,
Diopter adjustment range ±5 diopter
View field 5°,
Diopter adjustment range ±5 diopter
View field 5°
Apertures 2° / 1° collimation only 2° / 1° / 0.2°/ 0.1° 3° / 2° / 1° / 0.2°/ 0.1° 2° / 1° / 0.2°/ 0.1° 2° / 1° / 0.2°
Measurement Distance 350 mm to Inf. 350 mm to Inf. 350 mm to Inf.
Spot Size at 1m SR-LEDH SR-LEDW
SR-LEDW-5N
SR-UL2
SR-UL2s
SR-UL1R SR-3AR BM-5AC BM-7AS BM-9A
32.2 mm 32.2 mm 32.8 mm 32.3 mm
16.1 mm 16.1 mm 16.4 mm 16.2 mm
0.2° NA 3.2 mm 3.3 mm 3.23 mm
0.1° NA 1.6 mm 1.6 mm NA
Spot Size at 35cm SR-LEDH SR-LEDW
SR-LEDW-5N
SR-UL2
SR-UL2s
SR-UL1R SR-3AR BM-5AC BM-7AS BM-9A
10 mm 10 mm 10 mm 9.5 mm
5 mm 5 mm 5 mm 4.8 mm
0.2° NA 1 mm 1 mm 0.95 mm
0.1° NA 0.5 mm 0.5 mm NA
Luminance Range SR-LEDH SR-LEDW
SR-LEDW-5N
SR-UL2
SR-UL2s
SR-UL1R SR-3AR BM-5AC BM-7AS BM-9A
Min Lv (cd/m2) 10 0.0005 0.0005 0.001 0.1 0.00005 0.01 0.01
Max Lv (cd/m2) 4,500,000 5,000,000 300,000 1,200,000 12,000,000 28,000,000
Accuracy SR-LEDH SR-LEDW
SR-LEDW-5N
SR-UL2
SR-UL2s
SR-UL1R SR-3AR BM-5AC BM-7AS BM-9A
Luminance Accuracy ±2% (for standard illuminant A) ±4% (for standard illuminant A) ±4% for L under 5 cd/m2, ±2% for L over 5 cd/m2 ±2% of reading ±2 digit
Color Accuracy ±0.002 in 1931 CIE x,y Space ±0.005 in 1931 CIE x,y Space ±0.002 in 1931 CIE x,y Space NA
More Info LEDH LEDW
LEDW-5N
UL2
UL2s
UL1R 3AR BM-5AC BM-7AS BM-9A
Link to Product Page SR-LEDH SR-LEDW SR-UL2 SR-UL1R SR-3AR BM-5AC BM-7AS BM-9A