Cokin Z173 Z-Pro Varicolor Blue/Yellow Filter

The Cokin Z-Pro Series Z173 Varicolor Blue/Yellow Filter is a specialty creative filter designed for photographers who want to introduce controlled color effects directly at the point of capture. Measuring 100 x 100mm to fit the Cokin Z-Pro filter holder system, the Z173 uses a polarization-based mechanism to shift the color of reflections between blue and yellow as you rotate the filter. This gives you real-time, in-viewfinder control over the color tone and intensity — an effect that is difficult to convincingly replicate in post-processing because it selectively affects reflective surfaces while leaving non-reflective areas largely unchanged.

Constructed from CR-39 organic glass, the Z173 is notably lighter and more impact-resistant than equivalent glass filters, which is a practical advantage for location and outdoor shooting where gear takes a beating. Pairing the Z173 with a standard neutral polarizer in the Z-Pro holder's stacking slots opens up a broader palette of intermediate colors beyond the default blue-yellow range, adding further creative flexibility. The Z-Pro format also means a single filter covers multiple lens diameters via adapter rings, making it a versatile addition for photographers who shoot with various focal lengths. The trade-off of the square filter system is additional setup time and bulk compared to screw-on filters, but for deliberate creative work, the Z173 delivers a distinctive look that sets images apart.