LS-100 & LS-110 Spot Luminance Photometers

Konica Minolta LS-100 Spot Luminance Photometer

Affordable, portable & simple-to-use spot photometers

The LS-100 & LS-110 from Konica Minolta are portable spot luminance meters with a 1° or 1/3° measurement field of view, respectively. They are affordable and routinely used for measuring the brightness of displays and other light sources in units of candelas per sq. meter (cd/m²). Don't confuse affordability with low specification, though. The spectral response of the meter's silicon photodiode is matched to within 8% of the CIE standard observer function for photopic vision using special filters. The LS-100 & -110 provide measurements from 0.001 to 299,900 cd/m².

Low Glare SLR Viewing Optics

Convenient SLR viewing optics allow the operator to view through the meter to target the spot on the device under test for luminance measurements. Both the LS-100 and LS-110 have a 9° field of view with a black spot in the centre of the field that corresponds to the 1° or 1/3° degree measurement spots. The operator focusses the lens on the front of the meter on the device under test and aligns the black spot over the desired area on the light source. It is important that luminance meters only collect light from the intended spot and not inadvertently receive light from the surrounding area. This phenomonon is called "glare" and the stray light that results can seriously corrupt measurements of the contrast ratio of a display. Fortunately, both the LS-100 and LS-110 suffer from very low stray light with flare factors of less than 1.5%.

Up Close & Personal

With a minimum focal distance of 1014mm, the LS-100 provides for a 1° field of view and measurement spot size of ø14.4mm, while the 1/3° view of the LS-110 results in a reduced spot size of ø4.8mm. For certain light sources (for example, LED indicators and instrument panel legends), smaller measurement spots are required. To reduced the measurement area, the LS-100 & -110 are available with a chioce of four optional close-up lenses. These bring the minimum spot size of the LS-100 and LS-110 down to ø1.3 and ø0.4mm, respectively.

Many Advanced Features

The LS-100 and LS-110 include the facility to calibrate the meter against a user-selected reference source, and a numerical colour correction factor can be entered to compensate for the different spectral power distributions from a variety of light sources. A reference reading can be stored for luminance ratio measurements and the meters can record a peak luminance value. For connection to a PC, an RS-232C (serial) interface is fitted. The ease-of-use of the meter can be enhanced with an optional angled view finder which allows the operator to look down rather than have to stoop to view through the standard view finder. A long eye-relief eyepiece is also available which allows the operator to look through the view finder from a distance of 5cm away.

Specifications & Ordering Information

Model	LS-100	LS-110

Sensor	Silicon photodiode
Spectral Response	Photopic - CIE V(l)
F₁' (Spectral Mismatch to CIE)	Within 8%
Measuring Angle	1°	1/3°
Optical System	85mm, f/2.8 lens, SLR viewing system
Flare Factor	< 1.5%
View Angle	9°
Focussing Distance	1014 mm to infinity
Min. Measurement Spot	ø14.4 mm	ø4.8 mm
with 153 close-up lens	ø8.0mm	ø2.7mm
with 135 close-up lens	ø5.2mm	ø1.8mm
with 122 close-up lens	ø3.2mm	ø1.1mm
with 110 close-up lens	ø1.3mm	ø0.4mm
Response Time	FAST: sampling time 0.1s, display update 0.8 - 1.0s
	SLOW: sampling time 0.4s, display update 1.4 - 1.6s
Measurement Units	candelas per sq. meter (cd/m²) or foot Lamberts (fL) - selectable
Range - FAST	0.001 - 299,990 cd/m²	0.01 - 999,900 cd/m²
	0.001 - 87,530 fL	0.01 - 291,800 fL
Range - SLOW	0.001 - 49,990 cd/m²	0.01 - 499,900 cd/m²
	0.001 - 14,590 fL	0.01 - 145,900 fL
Accuracy (< 0.999 cd/m²)	±2% ± 2 digits (Illuminant A)	-
Accuracy (> 1.000 cd/m²)	±2% ± 1 digit (Illuminant A)	-
Accuracy (> 9.99 cd/m²)	-	±2% ± 2 digits (Illuminant A)
Accuracy (< 10.00 cd/m²)	-	±2% ± 1 digit (Illuminant A)
Repeatability (< 0.999 cd/m²)	±2% ± 2 digits (Illuminant A)	-
Repeatability (> 1.000 cd/m²)	±2% ± 1 digit (Illuminant A)	-
Repeatability (> 9.99 cd/m²)	-	±2% ± 2 digits (Illuminant A)
Repeatability (< 10.00 cd/m²)	-	±2% ± 1 digit (Illuminant A)
Drift	±3% ± 1 digit of value displayed at 20°C
Calibration Mode	Minolta or user-selected standard (selectable)
Colour Correction Mode	Numerical input (0.001 ... 9.999)
Reference Luminance	1 (set by numerical input or measurement)
Measurement Modes	Luminance, luminance ratio, peak luminance or luminance ratio
External Display	4-digit LCD with additional indications
Viewfinder Display	4-digit LCD with LED backlight
Data Interface	RS-232C (4800 baud)
External Control	Measurement process can be started externally via the data interface
Power	1 x 9V battery
Operating Environment	0 to 40°C, relative humidity < 85% (35°C), non-condensing
Storage Environment	-20 to 55°C, relative humidity < 85% (35°C), non-condensing
Dimensions	79 x 208 x 150mm
Weight (without battery)	850g

Accessories Included
	Lens cap
	Eyepiece cap
	ND eyepiece filter
	Case
	9V battery
Optional Accessories
	Calibration certificate
	Close-up lens (153)
	Close-up lens (135)
	Close-up lens (122)
	Close-up lens (110)
	Long eye relief eye piece
	Angle view finder
	Spectral sensitivity curve datasheet
	Acceptance angle datasheet
	Interface cable (LS-A11)