Optical filter and imaging device

An optical filter comprising:

• a resin substrate having a thickness of 20 μm or more and 110 μm or less;
• an absorption layer having a thickness of 0.25 μm or more and 12 μm or less and being disposed on at least one principal surface of the resin substrate;
• and
• dielectric multilayer films disposed as an outermost layer on both principal surfaces of the resin substrate, wherein:
• at least one of the dielectric multilayer films is a near-infrared reflection layer;
• the resin substrate comprises, as a main component, a first transparent resin having a glass transition temperature of 170° C. or more, the first transparent resin having, when a thickness thereof is 100 μm, in a spectral transmittance curve over a wavelength range of 350 nm to 1,100 nm, an average internal transmittance in a wavelength range of 350 nm to 450 nm being 95% or more, a minimum internal transmittance in a wavelength range of 400 nm to 450 nm being 97% or more, and a wavelength at which an internal transmittance becomes 90% in a wavelength range of 500 nm or less being 350 nm or less;
• the first transparent resin comprises at least one resin selected from a polyimide resin and a polycarbonate resin;
• the absorption layer comprises a near-infrared absorbing dye (A) and a second transparent resin having a glass transition temperature of 170° C. or more, and the near-infrared absorbing dye (A) satisfies the following (ii-1) and (ii-2) in relation to the second transparent resin:
• (ii-1) in a spectral transmittance curve over a wavelength range of 400 nm to 800 nm as measured in a state of the near-infrared absorbing dye (A) being contained in the second transparent resin, a maximum absorption wavelength λmax(A)TR is within a wavelength range of 680 nm to 745 nm;
• and
• (ii-2) in a spectral transmittance curve over a wavelength range of 350 nm to 1,100 nm when the near-infrared dye (A) is incorporated into the second transparent resin and the internal transmittance at the maximum absorption wavelength λmax(A)TR is adjusted to 1%, both an average internal transmittance T435-500ave(A)TR for light in a wavelength range of 435 nm to 500 nm and an average internal transmittance T500-600ave(A)TR for light in a wavelength range of 500 nm to 600 nm are 94% or more;
• the second transparent resin is a polyimide resin;
• and
• an absolute value of a difference between an average transmittance of the optical filter in a range of 380 nm to 425 nm at an incident angle of 0° and an average transmittance of the optical filter in a range of 380 nm to 425 nm at an incident angle of 30° is 3% or less.