These are light balancing filters used to decrease the color temperature slightly for a warmer (redder) tone.
Corrects the tendency toward bluish tones. For example, the 81A should be selected when using tungsten Type B color film (3200°K) with photoflood lamps (3400°K) These filters can be used together.
These popular filters are renowned for their ability to minimize reflection at the filter surfaces which reduces flare and ghosting. The result is an average light transmission of over 97%, giving sharp contrast and well balanced color. HOYA HMC filters are recommended for enhancing the performance of today's multicoated lenses.
81" series are color corrective filters that 'warm' bluish tones. They are availed in several strengths (A, B, C & EF) with 'A' being the mildest warming effect.
• Available in all popular sizes.
Reduces excess blue from flash indoors or in daylight flash-fill.
Warms (balances) sea, sky and high altitude shots.
Adds healthy look to skintones shot in open shade or overcast.
Multi coated for flare prevention.
For more information about, Hoya 67mm HMC 81C Warming Glass Filter website.