[argyllcms] Re: A better way to measure paper white?
- From: Gerhard Fuernkranz <nospam456@xxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Sat, 31 Oct 2009 20:35:53 +0100
Omari Stephens wrote:
> Err... four strobes? That seems like serious overkill. How far is
> the target from your lens, and what focal length and exposure settings
> are you using? I would expect a single strobe shooting directly at
> the target to be able to illuminate it properly and without any
> noticeable fall-off — unless you're using a giant target, the flash's
> hotspot should be able to cover it easily.
Well, in order to achieve a good illuminance uniformity, I would also
recommend a symmetric setup with (at least) two equal light sources. A
single light source is IMO only sufficient if
* the target can be illuminated under a steep angle
[ optimally orthogonal to the surface - but this is rather not an
option due to specular reflections ]
* or otherwise (using a flatter angle) only if the distance between
target and light source is VERY LARGE
[ For instance, a distance of about 150(!) times the width of the
target is necessary to achieve 1% illuminance uniformity, when
using a single point source and 45° illumination angle:
# note: 1/sqrt(2) = sin(45°) = cos(45°)
octave:6> x = z = 150/sqrt(2); ((x-0.5)^2+z^2)/((x+0.5)^2+z^2)
ans = 0.99062 (==> 1% between brighter and darker edge)
The sun as a single light source would certainly meet this
criterion :-)
Clouds or reflections from nearby other object may still disturb
uniformity though, so one still needs to be careful when
photographing a target under sun light ]
* and the target is perfectly flat
[ multiple light sources also reduce (compensate) the impacts of a
non-flat, slightly curved surface ]
In order to get a feeling for the impact of the illumination setup on
the uniformity, please find below a simple illustration of the spatiall
illuminance distribution across a target,
* a) for a single light source (coming only from left) and
* b) for two symmetric light sources (coming from left and right),
* for different distances between target and light source(s)
1 x width of the target ... 10 x width of the target
* assuming a 45° illumination angle,
* making the simplified assumption that the light sources are point
sources (thus having the property that the illuminance is
proportional to 1/d^2, where d is the distance from the light source),
* and assuming that the whole setup is located in a dark room with
infinite size, so that the result is not affected by any
reflections in the room.
[ Light sources with a larger diameter (say diameter > 0.1 * distance -
e.g. flash or lamp with large diffuser) will likely result in better
uniformity than point sources. Reflections in a real-world room can
improve or deteriorate the uniformity - however the effect will be hard
to predict. ]
Example result picked from below:
In order to obtain a uniformity of better than 1%, with a 45° two-lamp
setup, a distance between each lamp and the center of the target of >= 7
x width of the target is required. On the other hand, with a single lamp
and the same angle and distance, only a uniformity of ~20% is achieved.
Regards,
Gerhard
-------------------------------------------------------------------------------
Angle = 45.0
Distance lamp(s) <-> center of target = 1.0 x target width:
Spatial illuminace distribution across the target =>
(illuminace at the points of a 11x9 grid covering the target area)
I_one_lamp =
142.3 132.6 121.1 109.0 97.2 86.2 76.3 67.4 59.7 53.0
47.2
158.0 146.1 132.3 118.0 104.3 91.7 80.6 70.8 62.3 55.1
48.8
171.6 157.7 141.7 125.4 110.1 96.2 83.9 73.4 64.3 56.6
50.1
180.9 165.5 148.0 130.4 113.8 99.0 86.1 75.0 65.6 57.6
50.8
184.2 168.3 150.2 132.1 115.1 100.0 86.8 75.6 66.0 57.9
51.1
180.9 165.5 148.0 130.4 113.8 99.0 86.1 75.0 65.6 57.6
50.8
171.6 157.7 141.7 125.4 110.1 96.2 83.9 73.4 64.3 56.6
50.1
158.0 146.1 132.3 118.0 104.3 91.7 80.6 70.8 62.3 55.1
48.8
142.3 132.6 121.1 109.0 97.2 86.2 76.3 67.4 59.7 53.0
47.2
I_two_lamps =
94.8 92.8 90.4 88.2 86.7 86.2 86.7 88.2 90.4 92.8
94.8
103.4 100.6 97.3 94.4 92.4 91.7 92.4 94.4 97.3 100.6
103.4
110.8 107.1 103.0 99.4 97.0 96.2 97.0 99.4 103.0 107.1
110.8
115.9 111.5 106.8 102.7 100.0 99.0 100.0 102.7 106.8 111.5
115.9
117.6 113.1 108.1 103.8 101.0 100.0 101.0 103.8 108.1 113.1
117.6
115.9 111.5 106.8 102.7 100.0 99.0 100.0 102.7 106.8 111.5
115.9
110.8 107.1 103.0 99.4 97.0 96.2 97.0 99.4 103.0 107.1
110.8
103.4 100.6 97.3 94.4 92.4 91.7 92.4 94.4 97.3 100.6
103.4
94.8 92.8 90.4 88.2 86.7 86.2 86.7 88.2 90.4 92.8
94.8
Center = 100 %
One-Lamp:
Darkest = 47.23 %
Brightest = 184.20 %
Max - Min = 136.96 % (non-uniformity)
Two-Lamp:
Darkest = 86.21 %
Brightest = 117.65 %
Max - Min = 31.44 % (non-uniformity)
-------------------------------------------------------------------------------
Angle = 45.0
Distance lamp(s) <-> center of target = 2.0 x target width:
Spatial illuminace distribution across the target =>
(illuminace at the points of a 11x9 grid covering the target area)
I_one_lamp =
133.5 125.4 117.6 110.1 102.9 96.2 89.8 83.9 78.5 73.4
68.7
136.7 128.3 120.1 112.2 104.8 97.8 91.3 85.2 79.5 74.3
69.5
139.1 130.4 121.9 113.8 106.2 99.0 92.3 86.1 80.3 75.0
70.1
140.6 131.6 123.0 114.8 107.0 99.8 93.0 86.7 80.8 75.5
70.5
141.1 132.1 123.4 115.1 107.3 100.0 93.2 86.8 81.0 75.6
70.6
140.6 131.6 123.0 114.8 107.0 99.8 93.0 86.7 80.8 75.5
70.5
139.1 130.4 121.9 113.8 106.2 99.0 92.3 86.1 80.3 75.0
70.1
136.7 128.3 120.1 112.2 104.8 97.8 91.3 85.2 79.5 74.3
69.5
133.5 125.4 117.6 110.1 102.9 96.2 89.8 83.9 78.5 73.4
68.7
I_two_lamps =
101.1 99.4 98.0 97.0 96.4 96.2 96.4 97.0 98.0 99.4
101.1
103.1 101.3 99.8 98.7 98.0 97.8 98.0 98.7 99.8 101.3
103.1
104.6 102.7 101.1 100.0 99.2 99.0 99.2 100.0 101.1 102.7
104.6
105.5 103.5 101.9 100.7 100.0 99.8 100.0 100.7 101.9 103.5
105.5
105.8 103.8 102.2 101.0 100.2 100.0 100.2 101.0 102.2 103.8
105.8
105.5 103.5 101.9 100.7 100.0 99.8 100.0 100.7 101.9 103.5
105.5
104.6 102.7 101.1 100.0 99.2 99.0 99.2 100.0 101.1 102.7
104.6
103.1 101.3 99.8 98.7 98.0 97.8 98.0 98.7 99.8 101.3
103.1
101.1 99.4 98.0 97.0 96.4 96.2 96.4 97.0 98.0 99.4
101.1
Center = 100 %
One-Lamp:
Darkest = 68.68 %
Brightest = 141.05 %
Max - Min = 72.38 % (non-uniformity)
Two-Lamp:
Darkest = 96.15 %
Brightest = 105.84 %
Max - Min = 9.68 % (non-uniformity)
-------------------------------------------------------------------------------
Angle = 45.0
Distance lamp(s) <-> center of target = 3.0 x target width:
Spatial illuminace distribution across the target =>
(illuminace at the points of a 11x9 grid covering the target area)
I_one_lamp =
123.5 118.1 112.8 107.8 102.9 98.3 93.8 89.6 85.5 81.7
78.0
124.7 119.2 113.8 108.7 103.7 99.0 94.5 90.2 86.1 82.2
78.5
125.5 120.0 114.5 109.3 104.3 99.6 95.0 90.6 86.5 82.6
78.9
126.1 120.4 115.0 109.7 104.7 99.9 95.3 90.9 86.8 82.8
79.1
126.3 120.6 115.1 109.9 104.8 100.0 95.4 91.0 86.8 82.9
79.1
126.1 120.4 115.0 109.7 104.7 99.9 95.3 90.9 86.8 82.8
79.1
125.5 120.0 114.5 109.3 104.3 99.6 95.0 90.6 86.5 82.6
78.9
124.7 119.2 113.8 108.7 103.7 99.0 94.5 90.2 86.1 82.2
78.5
123.5 118.1 112.8 107.8 102.9 98.3 93.8 89.6 85.5 81.7
78.0
I_two_lamps =
100.8 99.9 99.2 98.7 98.4 98.3 98.4 98.7 99.2 99.9
100.8
101.6 100.7 100.0 99.4 99.1 99.0 99.1 99.4 100.0 100.7
101.6
102.2 101.3 100.5 100.0 99.7 99.6 99.7 100.0 100.5 101.3
102.2
102.6 101.6 100.9 100.3 100.0 99.9 100.0 100.3 100.9 101.6
102.6
102.7 101.7 101.0 100.4 100.1 100.0 100.1 100.4 101.0 101.7
102.7
102.6 101.6 100.9 100.3 100.0 99.9 100.0 100.3 100.9 101.6
102.6
102.2 101.3 100.5 100.0 99.7 99.6 99.7 100.0 100.5 101.3
102.2
101.6 100.7 100.0 99.4 99.1 99.0 99.1 99.4 100.0 100.7
101.6
100.8 99.9 99.2 98.7 98.4 98.3 98.4 98.7 99.2 99.9
100.8
Center = 100 %
One-Lamp:
Darkest = 78.05 %
Brightest = 126.25 %
Max - Min = 48.20 % (non-uniformity)
Two-Lamp:
Darkest = 98.25 %
Brightest = 102.70 %
Max - Min = 4.45 % (non-uniformity)
-------------------------------------------------------------------------------
Angle = 45.0
Distance lamp(s) <-> center of target = 4.0 x target width:
Spatial illuminace distribution across the target =>
(illuminace at the points of a 11x9 grid covering the target area)
I_one_lamp =
117.8 113.8 109.9 106.2 102.5 99.0 95.6 92.3 89.2 86.1
83.2
118.4 114.4 110.5 106.7 103.0 99.4 96.0 92.7 89.5 86.4
83.5
118.9 114.8 110.9 107.0 103.3 99.8 96.3 93.0 89.8 86.7
83.7
119.1 115.0 111.1 107.2 103.5 99.9 96.5 93.1 89.9 86.8
83.8
119.2 115.1 111.2 107.3 103.6 100.0 96.5 93.2 90.0 86.8
83.9
119.1 115.0 111.1 107.2 103.5 99.9 96.5 93.1 89.9 86.8
83.8
118.9 114.8 110.9 107.0 103.3 99.8 96.3 93.0 89.8 86.7
83.7
118.4 114.4 110.5 106.7 103.0 99.4 96.0 92.7 89.5 86.4
83.5
117.8 113.8 109.9 106.2 102.5 99.0 95.6 92.3 89.2 86.1
83.2
I_two_lamps =
100.5 100.0 99.5 99.2 99.1 99.0 99.1 99.2 99.5 100.0
100.5
100.9 100.4 100.0 99.7 99.5 99.4 99.5 99.7 100.0 100.4
100.9
101.3 100.7 100.3 100.0 99.8 99.8 99.8 100.0 100.3 100.7
101.3
101.5 100.9 100.5 100.2 100.0 99.9 100.0 100.2 100.5 100.9
101.5
101.5 101.0 100.6 100.2 100.1 100.0 100.1 100.2 100.6 101.0
101.5
101.5 100.9 100.5 100.2 100.0 99.9 100.0 100.2 100.5 100.9
101.5
101.3 100.7 100.3 100.0 99.8 99.8 99.8 100.0 100.3 100.7
101.3
100.9 100.4 100.0 99.7 99.5 99.4 99.5 99.7 100.0 100.4
100.9
100.5 100.0 99.5 99.2 99.1 99.0 99.1 99.2 99.5 100.0
100.5
Center = 100 %
One-Lamp:
Darkest = 83.17 %
Brightest = 119.21 %
Max - Min = 36.04 % (non-uniformity)
Two-Lamp:
Darkest = 99.01 %
Brightest = 101.54 %
Max - Min = 2.53 % (non-uniformity)
-------------------------------------------------------------------------------
Angle = 45.0
Distance lamp(s) <-> center of target = 5.0 x target width:
Spatial illuminace distribution across the target =>
(illuminace at the points of a 11x9 grid covering the target area)
I_one_lamp =
114.3 111.2 108.1 105.1 102.2 99.4 96.6 93.9 91.3 88.8
86.4
114.7 111.5 108.4 105.4 102.5 99.6 96.9 94.2 91.6 89.0
86.6
114.9 111.7 108.7 105.6 102.7 99.8 97.1 94.4 91.7 89.2
86.7
115.1 111.9 108.8 105.8 102.8 100.0 97.2 94.5 91.8 89.3
86.8
115.1 111.9 108.8 105.8 102.9 100.0 97.2 94.5 91.9 89.3
86.8
115.1 111.9 108.8 105.8 102.8 100.0 97.2 94.5 91.8 89.3
86.8
114.9 111.7 108.7 105.6 102.7 99.8 97.1 94.4 91.7 89.2
86.7
114.7 111.5 108.4 105.4 102.5 99.6 96.9 94.2 91.6 89.0
86.6
114.3 111.2 108.1 105.1 102.2 99.4 96.6 93.9 91.3 88.8
86.4
I_two_lamps =
100.3 100.0 99.7 99.5 99.4 99.4 99.4 99.5 99.7 100.0
100.3
100.6 100.3 100.0 99.8 99.7 99.6 99.7 99.8 100.0 100.3
100.6
100.8 100.5 100.2 100.0 99.9 99.8 99.9 100.0 100.2 100.5
100.8
100.9 100.6 100.3 100.1 100.0 100.0 100.0 100.1 100.3 100.6
100.9
101.0 100.6 100.4 100.2 100.0 100.0 100.0 100.2 100.4 100.6
101.0
100.9 100.6 100.3 100.1 100.0 100.0 100.0 100.1 100.3 100.6
100.9
100.8 100.5 100.2 100.0 99.9 99.8 99.9 100.0 100.2 100.5
100.8
100.6 100.3 100.0 99.8 99.7 99.6 99.7 99.8 100.0 100.3
100.6
100.3 100.0 99.7 99.5 99.4 99.4 99.4 99.5 99.7 100.0
100.3
Center = 100 %
One-Lamp:
Darkest = 86.37 %
Brightest = 115.13 %
Max - Min = 28.76 % (non-uniformity)
Two-Lamp:
Darkest = 99.36 %
Brightest = 100.99 %
Max - Min = 1.63 % (non-uniformity)
-------------------------------------------------------------------------------
Angle = 45.0
Distance lamp(s) <-> center of target = 6.0 x target width:
Spatial illuminace distribution across the target =>
(illuminace at the points of a 11x9 grid covering the target area)
I_one_lamp =
111.9 109.3 106.8 104.3 101.9 99.6 97.2 95.0 92.8 90.6
88.6
112.2 109.6 107.0 104.6 102.1 99.8 97.4 95.2 93.0 90.8
88.7
112.3 109.7 107.2 104.7 102.3 99.9 97.6 95.3 93.1 90.9
88.8
112.4 109.8 107.3 104.8 102.4 100.0 97.6 95.4 93.2 91.0
88.9
112.5 109.9 107.3 104.8 102.4 100.0 97.7 95.4 93.2 91.0
88.9
112.4 109.8 107.3 104.8 102.4 100.0 97.6 95.4 93.2 91.0
88.9
112.3 109.7 107.2 104.7 102.3 99.9 97.6 95.3 93.1 90.9
88.8
112.2 109.6 107.0 104.6 102.1 99.8 97.4 95.2 93.0 90.8
88.7
111.9 109.3 106.8 104.3 101.9 99.6 97.2 95.0 92.8 90.6
88.6
I_two_lamps =
100.2 100.0 99.8 99.7 99.6 99.6 99.6 99.7 99.8 100.0
100.2
100.4 100.2 100.0 99.9 99.8 99.8 99.8 99.9 100.0 100.2
100.4
100.6 100.3 100.1 100.0 99.9 99.9 99.9 100.0 100.1 100.3
100.6
100.7 100.4 100.2 100.1 100.0 100.0 100.0 100.1 100.2 100.4
100.7
100.7 100.4 100.2 100.1 100.0 100.0 100.0 100.1 100.2 100.4
100.7
100.7 100.4 100.2 100.1 100.0 100.0 100.0 100.1 100.2 100.4
100.7
100.6 100.3 100.1 100.0 99.9 99.9 99.9 100.0 100.1 100.3
100.6
100.4 100.2 100.0 99.9 99.8 99.8 99.8 99.9 100.0 100.2
100.4
100.2 100.0 99.8 99.7 99.6 99.6 99.6 99.7 99.8 100.0
100.2
Center = 100 %
One-Lamp:
Darkest = 88.56 %
Brightest = 112.47 %
Max - Min = 23.92 % (non-uniformity)
Two-Lamp:
Darkest = 99.56 %
Brightest = 100.69 %
Max - Min = 1.13 % (non-uniformity)
-------------------------------------------------------------------------------
Angle = 45.0
Distance lamp(s) <-> center of target = 7.0 x target width:
Spatial illuminace distribution across the target =>
(illuminace at the points of a 11x9 grid covering the target area)
I_one_lamp =
110.2 108.0 105.9 103.8 101.7 99.7 97.7 95.7 93.8 92.0
90.1
110.4 108.2 106.0 103.9 101.8 99.8 97.8 95.9 94.0 92.1
90.3
110.5 108.3 106.2 104.0 102.0 99.9 97.9 96.0 94.1 92.2
90.3
110.6 108.4 106.2 104.1 102.0 100.0 98.0 96.0 94.1 92.2
90.4
110.6 108.4 106.2 104.1 102.0 100.0 98.0 96.0 94.1 92.2
90.4
110.6 108.4 106.2 104.1 102.0 100.0 98.0 96.0 94.1 92.2
90.4
110.5 108.3 106.2 104.0 102.0 99.9 97.9 96.0 94.1 92.2
90.3
110.4 108.2 106.0 103.9 101.8 99.8 97.8 95.9 94.0 92.1
90.3
110.2 108.0 105.9 103.8 101.7 99.7 97.7 95.7 93.8 92.0
90.1
I_two_lamps =
100.2 100.0 99.9 99.8 99.7 99.7 99.7 99.8 99.9 100.0
100.2
100.3 100.1 100.0 99.9 99.8 99.8 99.8 99.9 100.0 100.1
100.3
100.4 100.2 100.1 100.0 99.9 99.9 99.9 100.0 100.1 100.2
100.4
100.5 100.3 100.2 100.1 100.0 100.0 100.0 100.1 100.2 100.3
100.5
100.5 100.3 100.2 100.1 100.0 100.0 100.0 100.1 100.2 100.3
100.5
100.5 100.3 100.2 100.1 100.0 100.0 100.0 100.1 100.2 100.3
100.5
100.4 100.2 100.1 100.0 99.9 99.9 99.9 100.0 100.1 100.2
100.4
100.3 100.1 100.0 99.9 99.8 99.8 99.8 99.9 100.0 100.1
100.3
100.2 100.0 99.9 99.8 99.7 99.7 99.7 99.8 99.9 100.0
100.2
Center = 100 %
One-Lamp:
Darkest = 90.14 %
Brightest = 110.61 %
Max - Min = 20.47 % (non-uniformity)
Two-Lamp:
Darkest = 99.67 %
Brightest = 100.51 %
Max - Min = 0.83 % (non-uniformity)
-------------------------------------------------------------------------------
Angle = 45.0
Distance lamp(s) <-> center of target = 8.0 x target width:
Spatial illuminace distribution across the target =>
(illuminace at the points of a 11x9 grid covering the target area)
I_one_lamp =
108.9 107.0 105.2 103.3 101.5 99.8 98.0 96.3 94.6 93.0
91.3
109.1 107.2 105.3 103.4 101.6 99.9 98.1 96.4 94.7 93.1
91.4
109.2 107.2 105.4 103.5 101.7 99.9 98.2 96.5 94.8 93.1
91.5
109.2 107.3 105.4 103.6 101.8 100.0 98.2 96.5 94.8 93.2
91.5
109.2 107.3 105.4 103.6 101.8 100.0 98.2 96.5 94.8 93.2
91.6
109.2 107.3 105.4 103.6 101.8 100.0 98.2 96.5 94.8 93.2
91.5
109.2 107.2 105.4 103.5 101.7 99.9 98.2 96.5 94.8 93.1
91.5
109.1 107.2 105.3 103.4 101.6 99.9 98.1 96.4 94.7 93.1
91.4
108.9 107.0 105.2 103.3 101.5 99.8 98.0 96.3 94.6 93.0
91.3
I_two_lamps =
100.1 100.0 99.9 99.8 99.8 99.8 99.8 99.8 99.9 100.0
100.1
100.2 100.1 100.0 99.9 99.9 99.9 99.9 99.9 100.0 100.1
100.2
100.3 100.2 100.1 100.0 100.0 99.9 100.0 100.0 100.1 100.2
100.3
100.4 100.2 100.1 100.0 100.0 100.0 100.0 100.0 100.1 100.2
100.4
100.4 100.2 100.1 100.1 100.0 100.0 100.0 100.1 100.1 100.2
100.4
100.4 100.2 100.1 100.0 100.0 100.0 100.0 100.0 100.1 100.2
100.4
100.3 100.2 100.1 100.0 100.0 99.9 100.0 100.0 100.1 100.2
100.3
100.2 100.1 100.0 99.9 99.9 99.9 99.9 99.9 100.0 100.1
100.2
100.1 100.0 99.9 99.8 99.8 99.8 99.8 99.8 99.9 100.0
100.1
Center = 100 %
One-Lamp:
Darkest = 91.34 %
Brightest = 109.23 %
Max - Min = 17.89 % (non-uniformity)
Two-Lamp:
Darkest = 99.75 %
Brightest = 100.39 %
Max - Min = 0.64 % (non-uniformity)
-------------------------------------------------------------------------------
Angle = 45.0
Distance lamp(s) <-> center of target = 9.0 x target width:
Spatial illuminace distribution across the target =>
(illuminace at the points of a 11x9 grid covering the target area)
I_one_lamp =
107.9 106.3 104.6 103.0 101.4 99.8 98.2 96.7 95.2 93.7
92.3
108.0 106.4 104.7 103.1 101.5 99.9 98.3 96.8 95.3 93.8
92.4
108.1 106.4 104.8 103.1 101.5 100.0 98.4 96.9 95.4 93.9
92.4
108.1 106.5 104.8 103.2 101.6 100.0 98.4 96.9 95.4 93.9
92.4
108.2 106.5 104.8 103.2 101.6 100.0 98.4 96.9 95.4 93.9
92.5
108.1 106.5 104.8 103.2 101.6 100.0 98.4 96.9 95.4 93.9
92.4
108.1 106.4 104.8 103.1 101.5 100.0 98.4 96.9 95.4 93.9
92.4
108.0 106.4 104.7 103.1 101.5 99.9 98.3 96.8 95.3 93.8
92.4
107.9 106.3 104.6 103.0 101.4 99.8 98.2 96.7 95.2 93.7
92.3
I_two_lamps =
100.1 100.0 99.9 99.9 99.8 99.8 99.8 99.9 99.9 100.0
100.1
100.2 100.1 100.0 99.9 99.9 99.9 99.9 99.9 100.0 100.1
100.2
100.3 100.1 100.1 100.0 100.0 100.0 100.0 100.0 100.1 100.1
100.3
100.3 100.2 100.1 100.0 100.0 100.0 100.0 100.0 100.1 100.2
100.3
100.3 100.2 100.1 100.0 100.0 100.0 100.0 100.0 100.1 100.2
100.3
100.3 100.2 100.1 100.0 100.0 100.0 100.0 100.0 100.1 100.2
100.3
100.3 100.1 100.1 100.0 100.0 100.0 100.0 100.0 100.1 100.1
100.3
100.2 100.1 100.0 99.9 99.9 99.9 99.9 99.9 100.0 100.1
100.2
100.1 100.0 99.9 99.9 99.8 99.8 99.8 99.9 99.9 100.0
100.1
Center = 100 %
One-Lamp:
Darkest = 92.28 %
Brightest = 108.16 %
Max - Min = 15.88 % (non-uniformity)
Two-Lamp:
Darkest = 99.80 %
Brightest = 100.31 %
Max - Min = 0.50 % (non-uniformity)
-------------------------------------------------------------------------------
Angle = 45.0
Distance lamp(s) <-> center of target = 10.0 x target width:
Spatial illuminace distribution across the target =>
(illuminace at the points of a 11x9 grid covering the target area)
I_one_lamp =
107.1 105.6 104.2 102.7 101.3 99.8 98.4 97.1 95.7 94.4
93.0
107.2 105.7 104.2 102.8 101.3 99.9 98.5 97.1 95.8 94.4
93.1
107.3 105.8 104.3 102.8 101.4 100.0 98.6 97.2 95.8 94.5
93.1
107.3 105.8 104.3 102.9 101.4 100.0 98.6 97.2 95.8 94.5
93.2
107.3 105.8 104.3 102.9 101.4 100.0 98.6 97.2 95.8 94.5
93.2
107.3 105.8 104.3 102.9 101.4 100.0 98.6 97.2 95.8 94.5
93.2
107.3 105.8 104.3 102.8 101.4 100.0 98.6 97.2 95.8 94.5
93.1
107.2 105.7 104.2 102.8 101.3 99.9 98.5 97.1 95.8 94.4
93.1
107.1 105.6 104.2 102.7 101.3 99.8 98.4 97.1 95.7 94.4
93.0
I_two_lamps =
100.1 100.0 99.9 99.9 99.9 99.8 99.9 99.9 99.9 100.0
100.1
100.2 100.1 100.0 99.9 99.9 99.9 99.9 99.9 100.0 100.1
100.2
100.2 100.1 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.1
100.2
100.2 100.1 100.1 100.0 100.0 100.0 100.0 100.0 100.1 100.1
100.2
100.2 100.2 100.1 100.0 100.0 100.0 100.0 100.0 100.1 100.2
100.2
100.2 100.1 100.1 100.0 100.0 100.0 100.0 100.0 100.1 100.1
100.2
100.2 100.1 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.1
100.2
100.2 100.1 100.0 99.9 99.9 99.9 99.9 99.9 100.0 100.1
100.2
100.1 100.0 99.9 99.9 99.9 99.8 99.9 99.9 99.9 100.0
100.1
Center = 100 %
One-Lamp:
Darkest = 93.04 %
Brightest = 107.32 %
Max - Min = 14.28 % (non-uniformity)
Two-Lamp:
Darkest = 99.84 %
Brightest = 100.25 %
Max - Min = 0.41 % (non-uniformity)
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