This paper presents the optical transparency and dynamic conductivity of suspended graphene. The optical transparency of suspended graphene is found to be determined by the fine structure constant, α = e²/ħc, which describes the coupling between light and relativistic electrons. Despite being only one atom thick, graphene absorbs about 2.3% (πα) of incident white light, a result of its unique electronic structure. This absorption translates directly into a universal dynamic conductivity G = e²/4ħ with a few percent accuracy. The study shows that the optical properties of graphene are defined by fundamental constants and not by material parameters. This is supported by theoretical models of ideal two-dimensional Dirac fermions and their extension into visible optics. The researchers fabricated large graphene membranes using micromechanical cleavage and PMMA layers, allowing for the creation of large, high-quality graphene membranes. Optical measurements revealed that graphene's opacity is practically independent of wavelength. However, deviations from constant opacity were observed for wavelengths shorter than 500 nm, attributed to surface contamination by hydrocarbons. Annealing the membranes in a hydrogen-argon atmosphere significantly improved their cleanliness. The dynamic conductivity of graphene was found to be remarkably close to the universal value of e²/4ħ, even for visible frequencies. The study also shows that the opacity of few-layer graphene increases proportionally with the number of layers. Theoretical analysis confirms that the optical properties of graphene are determined by its 2D nature and zero energy gap, not by the chiral properties of Dirac fermions. The paper concludes that the optical properties of suspended graphene are defined by fundamental constants and that the fine structure constant can be directly and accurately assessed through visual observation. The results highlight the unique electronic properties of graphene and its potential for applications in optoelectronics and other fields.This paper presents the optical transparency and dynamic conductivity of suspended graphene. The optical transparency of suspended graphene is found to be determined by the fine structure constant, α = e²/ħc, which describes the coupling between light and relativistic electrons. Despite being only one atom thick, graphene absorbs about 2.3% (πα) of incident white light, a result of its unique electronic structure. This absorption translates directly into a universal dynamic conductivity G = e²/4ħ with a few percent accuracy. The study shows that the optical properties of graphene are defined by fundamental constants and not by material parameters. This is supported by theoretical models of ideal two-dimensional Dirac fermions and their extension into visible optics. The researchers fabricated large graphene membranes using micromechanical cleavage and PMMA layers, allowing for the creation of large, high-quality graphene membranes. Optical measurements revealed that graphene's opacity is practically independent of wavelength. However, deviations from constant opacity were observed for wavelengths shorter than 500 nm, attributed to surface contamination by hydrocarbons. Annealing the membranes in a hydrogen-argon atmosphere significantly improved their cleanliness. The dynamic conductivity of graphene was found to be remarkably close to the universal value of e²/4ħ, even for visible frequencies. The study also shows that the opacity of few-layer graphene increases proportionally with the number of layers. Theoretical analysis confirms that the optical properties of graphene are determined by its 2D nature and zero energy gap, not by the chiral properties of Dirac fermions. The paper concludes that the optical properties of suspended graphene are defined by fundamental constants and that the fine structure constant can be directly and accurately assessed through visual observation. The results highlight the unique electronic properties of graphene and its potential for applications in optoelectronics and other fields.