Responsible for the synthesis of cyclic GMP (cGMP) in rods and cones of photoreceptors. Plays an essential role in phototransduction, by mediating cGMP replenishment (PubMed:7831337). May also participate in the trafficking of membrane-asociated proteins to the photoreceptor outer segment membrane (By similarity). GTP = 3',5'-cyclic GMP + diphosphate Activated by GUCA1B when free calcium ions concentration is low, and inhibited by GUCA1B when free calcium ions concentration is high (By similarity). Inhibited by RD3 (By similarity). Homodimer (PubMed:9153227). Interacts with RD3; promotes the exit of GUCY2F from the endoplasmic reticulum and its trafficking to the photoreceptor outer segments (By similarity). Expressed only in the eye. The protein kinase domain is predicted to be catalytically inactive. There are 9 conserved cysteine residues in sensory guanylate cyclases, 6 in the extracellular domain, which may be involved in intra- or interchain disulfide bonds. Belongs to the adenylyl cyclase class-4/guanylyl cyclase family.