Spectral Sensitivity of Test Paints

By John F. Pecora

 

 

The purpose of this paper is to determine the spectral sensitivity of paints using the wavelengths 514, 496, 488, 476 and 457nm from and Argon Ion Laser. A variety of paints and blends of paints were used. The camera that recorded the images was a Canon PowerShot S45.

  

Canon PowerShot S45 

Although I was not able to acquire the specific wavelength sensitivity of the camera, the below chart shows the signal amplitude vs. wavelength and was found at the Digit-Life.com web page.

 Canon PowerShot S45

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Signal amplitude vs. wavelength           ---                      Digit-Life.com

  

The Paints

 The paints are as follows from left to right top to bottom. All mixes were mixed approximately 50%-50% unless otherwise specified.

 

ROW 1

Delta Ceramcoat – Acrylic Paint - Golden Brown 02054

Apple Barrel Colors – Craft Paint - King’s Gold 20760

Windsor Newton Galeria – Flow Formula Acrylic – Titanium White

Apple Barrel Colors – Craft Paint – Baby Pink M20372

Windsor Newton Galeria – Flow Formula Acrylic – Permanent Green           Light and Windsor Newton Galeria – Flow Formula Acrylic – Winsor Violet

 

ROW 2

Gallery Glass Window Color – Water Color Textured Paint– Ruby Red 15315

Gallery Glass Window Color – Water Color Textured Paint– Ruby Red 15315 (Duplicate)

Windsor Newton Galeria – Flow Formula Acrylic – Cadmium Yellow Pale Hue

Gallery Glass Window Color – Water Color Textured Paint– Canyon Coral 15306

Windsor Newton Galeria – Flow Formula Acrylic – Permanent Green           Light and Windsor Newton Galeria – Flow Formula Acrylic – Cerulean Blue Hue

 

ROW 3

Windsor Newton Galeria – Flow Formula Acrylic – Permanent Green           Light

Windsor Newton Galeria – Flow Formula Acrylic – Permanent Green           Middle

Windsor Newton Galeria – Flow Formula Acrylic – Permanent Green           Deep

Windsor Newton Galeria – Flow Formula Acrylic – Phthalo Green

Windsor Newton Galeria – Flow Formula Acrylic – Cadmium Yellow Pale Hue and Windsor Newton Galeria – Flow Formula Acrylic – Titanium White

 

ROW 4

Windsor Newton Galeria – Flow Formula Acrylic – Cerulean Blue Hue

Windsor Newton Galeria – Flow Formula Acrylic – Cobalt Blue Hue

Windsor Newton Galeria – Flow Formula Acrylic – Ultramarine

Windsor Newton Galeria – Flow Formula Acrylic – Winsor Violet

Windsor Newton Galeria – Flow Formula Acrylic – Cadmium Yellow Pale Hue and Windsor Newton Galeria – Flow Formula Acrylic – Phthalo Green

 

ROW 5

Palmer Paint Products – Washable Poster Paint – Red 125608 (50%) and Palmer Paint Products – Washable Poster Paint – Yellow 127408 (50%)

Palmer Paint Products – Washable Poster Paint – Red 125608 (75%) and Palmer Paint Products – Washable Poster Paint – Yellow 127408 (25%)

Palmer Paint Products – Washable Poster Paint – Red 125608 (25%) and Palmer Paint Products – Washable Poster Paint – Yellow 127408 (75%)

Windsor Newton Galeria – Flow Formula Acrylic – Winsor Violet (10%)  and Windsor Newton Galeria – Flow Formula Acrylic – Titanium White (90%)

Windsor Newton Galeria – Flow Formula Acrylic – Cadmium Yellow Pale Hue and Windsor Newton Galeria – Flow Formula Acrylic – Ultra Marine

 

ROW 6

Windsor Newton Galeria – Flow Formula Acrylic – Phthalo Green (10%) and Windsor Newton Galeria – Flow Formula Acrylic – Titanium White (90%)

Windsor Newton Galeria – Flow Formula Acrylic – Ultra Marine (25%) and Windsor Newton Galeria – Flow Formula Acrylic – Titanium White (75%)

Windsor Newton Galeria – Flow Formula Acrylic – Ultra Marine (10%) and Windsor Newton Galeria – Flow Formula Acrylic – Titanium White (90%)

Windsor Newton Galeria – Flow Formula Acrylic – Winsor Violet (25%) and Windsor Newton Galeria – Flow Formula Acrylic – Titanium White (75%)

Windsor Newton Galeria – Flow Formula Acrylic – Cadmium Yellow (10%) and Windsor Newton Galeria – Flow Formula Acrylic – Windor Violet (90%)

 

 

 Laser Illumination

 

      The above photographs are of the paints with each set corresponding to a different illumination wavelength from an Argon Ion Laser. Total laser power was adjusted for each photograph such that output power illumination was equal (approximately 40mw total). The last photograph is of the paints illuminated with a quartz Halogen light. From left to right, top to bottom the illuminating wavelengths are as follows; 457nm, 476nm, 488nm, 496nm and 514nm respectively. It is interesting to note that the Titanium White comes out nearly white, or purest in all wavelengths.

 

In viewing the reflectivity of each of the sets and comparing them to the Titanium White the following discoveries were found. A visual scale was used with 10 being very reflective and 1 being minimally reflective.

 

514nm - Windsor Newton Galeria – Flow Formula Acrylic – Cadmium Yellow exhibited the best reflectivity for 514 while absorbing some/most of the other wavelengths.

514 – 9 Scale

496 – 6 Scale

488 – 4 Scale

476 – 3 Scale

457 – 2 Scale

 

496 – Windsor Newton Galeria – Flow Formula Acrylic – Permanent Green           Light exhibited the best reflectivity for 496 while absorbing some/most of the other wavelengths.

514 – 4 Scale

496 – 6 Scale

488 – 5 Scale

476 – 4 Scale

457 – 3 Scale

 

457 – Windsor Newton Galeria – Flow Formula Acrylic – Cobalt Blue Hue exhibited the best reflectivity for 457 while absorbing some/mos of the other wavelengths.

514 – 2 Scale

496 – 4 Scale

488 – 5 Scale

476 – 5 Scale

457 – 6 Scale

 

 

 

 The above is the entire set of photos converted to 16 bit gray scale with Corel Photo Paint and reinforced the paint selections for best matching wavelength.

 

 The above is the color photograph broken down into Red, Green and Blue by Corel Photo Paint and is the blue piece of the division.

 

 

 The above is the color photograph broken down into Red, Green and Blue by Corel Photo Paint and is the Green piece of the division.

 

Conclusion:

In conclusion I choose the Windsor Newton Galeria – Flow Formula Acrylic – Cadmium Yellow  for highest reflectivity of the 514 wavelengths while absorbing the most from the other wavelength. I choose the Windsor Newton Galeria – Flow Formula Acrylic – Cobalt Blue Hue for highest reflectivity to the 457 wavelengths while absorbing the most from the other wavelength. And I choose the Windsor Newton Galeria – Flow Formula Acrylic – Titanium White for highest reflectivity of both wavelengths.  In viewing the color triangle below (Thank you to Kaveh Bazargan) the different combinations of shift can be seen. With these three paints and a processing shift toward the red of 16% I can get parts of the object painted Cobalt Blue to replay in Green (about 530nm), the parts of the object painted Cadmium Yellow to replay in Orange (about 596nm) and the parts of the object painted Titanium White, which will reflect both wavelengths (530 and 596), to replay in yellow (563nm). In implementing this I created "The Model" hologram and the "Fish Tank" hologram both can be seen in the Photo Gallery.