What's the difference between laminated and hard coating filters?

Both laminated and hard coating filters aim to control light by selectively passing or blocking specific wavelengths, but they differ in their construction methods and resulting properties:

Laminated filters:

• Also known as "soft coatings," made by sandwiching colored dyes or gels between thin sheets of glass or plastic.

• Pros:
  • Lower cost, readily available, easier to customize for specific colors.
  • Can be thicker, offering high absorption for certain wavelengths.

• Cons:
  • Less durable, prone to scratches, moisture damage, and fading.
  • Lower optical performance, with higher scatter and lower blocking, affecting image quality.
  • Less temperature stable, potentially shifting in color with temperature changes.

Hard coating filters:

• Made by depositing thin layers of various materials (metals, oxides) onto a substrate through precise processes like physical vapor deposition.

• Pros:
  • Significantly more durable, resistant to scratches, moisture, and chemicals.
  • Higher optical performance, offering sharper cut-offs and lower scatter for better image quality.
  • More temperature stable, maintaining performance across wider temperature ranges.

• Cons:
  • Generally more expensive than laminated filters.
  • Customization options might be limited compared to laminated filters.

Summary:

• Choose laminated filters if: cost is the primary concern, you need specific color customization, or high absorption is paramount.

• Choose hard coating filters if: durability, high optical performance, and temperature stability are essential.