All Things Color for Film and Digital Cinema
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Posts Tagged ‘Macbeth’

Color Blindness – An amazing experiment –

 

Today I performed an interesting yet simple experiment.

 

Marcie - Color Test

Marcie - Color Test - Fig A

 

Regarding the LAST POST ON COLOR BLINDNESS I began pondering what an emulation of Color Blindness would look to to a person with such a “visually challenged color perception”.

As a test I invited two colleges to view an image both as natural color original and as a emulation of Color Blindness.

Here is the website I used to view the color emulation.

http://www.vischeck.com/vischeck/vischeckImage.php

Both images looked near identical to each viewer.

BUT here is the amazing bit. 

Using a Macbeth color chart Fig.B as a test, I then asked my friends to label the colors they saw.

Once again to their eyes the two images were ‘the same’ in color…….

 

Macbeth Test

Macbeth Test - Fig .B

No Macbeth  Name           Red/Green Deficient Name A      Red/Green Deficient Name B      
1 dark skin Dark Chocolate     Brown      
2 light skin Skin     Tan      
3 blue sky Light Blue     Light Blue      
4 foliage Olive Green     Green      
5 blue flower Light Blue     Light Blue      
6 bluish green Washed out green     Tan      
7 orange Terra-cotta     Light Green      
8 purplish blue Ultramarine     Purple      
9 moderate red Red Brick     green      
10 purple Night Sky      Purple      
11 yellow green Ochre Yellow     Yellow      
12 orange yellow Sunday Latte     Orange OR Green      
13 blue Meadow Morning     Blue      
14 green UltraMarine     Green      
15 red Brick Red     Green      
16 yellow Yellow Ochre     Yellow      
17 magenta Fuchsia – Lilac     Pink      
18 cyan Light Blue     Light Blue      
19 white Polar Scape            
20 neutral 8 Polar Scape 2            

Friend A interestingly noted wearing Polarized lenses made colors more intense and therefor more distinguishable.

Doubly interesting was the fact that Friend A  really liked 3D movies as the colors became more intense. I wonder if this is because the eye is being given two distinct references of polarized spectral information to help distinguish the colors.

I found it amazing that both friends saw the Pink in the aparently Grey patch on line 3 of the simulation Macbeth Chart. It seems almost identical to the grey patch below it. Anecdotally, Friend B told me a story about ordering a new grey kitchen bench a while back. He was mortified on coming home one day to find his new pink kitchen bench!

 

Adrian Hauser


The Macbeth Chart

The Macbeth chart is a color evaluation chart that represents and reflects the colors of nature under any illumination. It is used as a color rendition and reproduction target for both stills and motion picture imaging labs. Using the  given set of digital scientific values for each patch an operator can evaluate a given image exposed with the card and correct for color inconsistencies inherent in Digital imaging devices, film stocks, lens coatings, old lamps, printing stocks, printing paper, monitoring devices,….ect.

Below is the Macbeth Color Chart and its relative CIE and SMPTE-C RGB values.

Macbeth Color Chart

Macbeth Color Chart

 

 

 

 

 

 

 

 

 

No Name CIE_x CIE_y CIE_Y Hue Value Chroma RGB_TRIPLET
1 dark skin 0.400 0.350 10.1 3 YR 3.7 3.2 116 80 67
2 light skin 0.377 0.345 35.8 2.2 YR 6.47 4.1 196 149 129
3 blue sky 0.247 0.251 19.3 4.3 PB 4.95 5.5 91 122 155
4 foliage 0.337 0.422 13.3 6.7 GY 4.2 4.1 88 109 67
5 blue flower 0.265 0.240 24.3 9.7 PB 5.47 6.7 128 127 175
6 bluish green 0.261 0.343 43.1 2.5 BG 7 6 90 190 169
7 orange 0.506 0.407 30.1 5 YR 6 11 221 119 44
8 purplish blue 0.211 0.175 12.0 7.5 PB 4 10.7 71 90 164
9 moderate red 0.453 0.306 19.8 2.5 R 5 10 198 81 98
10 purple 0.285 0.202 6.6 5 P 3 7 93 60 107
11 yellow green 0.380 0.489 44.3 5 GY 7.1 9.1 158 88 64
12 orange yellow 0.473 0.438 43.1 10 YR 7 10.5 234 161 49
13 blue 0.187 0.129 6.1 7.5 PB 2.9 12.7 47 59 151
14 green 0.305 0.478 23.4 0.25 G 5.4 8.65 65 150 71
15 red 0.539 0.313 12.0 5 R 4 12 181 40 59
16 yellow 0.448 0.470 59.1 5 Y 8 11.1 241 200 38
17 magenta 0.364 0.233 19.8 2.5 RP 5 12 190 78 146
18 cyan 0.196 0.252 19.8 5 B 5 8 0 134 164
19 white 0.310 0.316 90.0 N 9.5 0 242 242 236
20 neutral 8 0.310 0.316 59.1 N 8 0 200 200 199
21 neutral 6.5 0.310 0.316 36.2 N 6.5 0 159 160 159
22 neutral 5 0.310 0.316 19.8 N 5 0 122 121 119
23 neutral 3.5 0.310 0.316 9.0 N 3.5 0 84 84 84
24 black 0.310 0.316 3.1 N 2 0 53 53 53