Both laminated and hard coating filters aim to control light by selectively passing or blocking specific wavelengths. However, they differ in their construction methods and resulting properties:
Laminated Filters
Also known as "soft coatings", laminated filters are 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
Hard coating filters are 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
- High absorption is paramount
Choose hard coating filters if:
- Durability, high optical performance, and temperature stability are essential
*By the way, most of the optical filter listing on syronoptics.com are hard-coating type optical filters.