The light transmission of an EMI shielded window is determined by the following factors:
Mesh Transmittance
EmiClare mesh provides brighter image quality through higher mesh transmittance.
Substrates
The following chart gives a guide of the light transmittance (T%) of the common substrates.
| Plain "float" glass | 90-92% |
| Clear polycarbonate* | 85-90% |
| Clear acrylic* | 85-90% |
| Clear polyester* | 83-88% |
* Varies with thickness due to internal dispersion and may also vary between suppliers.
Surface Finish
The following table quantifies the effect of the common surface finishes on optical transmittance.
| Surface Finish | Reduction in T% |
| Non Glare coatings 60-70 gloss | 2-3% |
| Non Glare coatings 80-90 | gloss 1% |
| Clear hard coats | <1% |
| MLAR coatings on glass | <1% |
| ITO coatings 12-15 ohms/square | 5-10% |
Finished Windows
By design EmiClare windows deliver improved optical performance.
| A: | Laminate with 0.75mm Non-Glare and clear Hard Coated polycarbonate. |
| B: | Laminate with 1.2mm glass. Plain finish to both surfaces. |
| C: | Laminate with 1.5mm Non-Glare and plain polycarbonate. |
| D: | Laminate with 1.2mm (MLAR) glass and 1.2mm plain glass. |