A camera comprising: a first optical structure (OPTaa) configured to refract and reflect a first beam (Rlaa) input from a first direction to output a second beam (Rlba) to a second direction with a width smaller than a width of the first beam (Rlaa); and a second optical structure (OPTba) configured to refract and reflect the second beam (Rlba) from the first optical structure to output a third beam (Rlca) to the first direction with a width greater than the width of the second beam, wherein a height of the first optical structure (OPTaa) and a height of the second optical structure (OPTba) are the same, wherein a width of the first beam (Rlaa) and a width of the third beam (Rlca) are the same, wherein the first optical structure (OPTaa) comprises a first reflection surface (RFaa) configured to reflect the first input beam, wherein a first angle between the first reflection surface (RFaa) and the second beam (Rlba) and a second angle between an orthogonal surface orthogonal to the first beam (Rlaa) and the first reflection surface are each greater than 0° and smaller than 45°, wherein a third angle between a second reflection surface (RFba) of the second optical structure (OPTba) and the second beam (Rlba) is identical to a fourth angle (θ1a) formed by the first reflection surface (RFaa) of the first optical structure (OPTaa) and the second beam (Rlba), wherein the first beam (Rlaa) is configured to be refracted by a first light incident surface (FRaa) of the first optical structure (OPTaa), configured to be reflected by the first reflection surface (RFaa) of the first optical structure (OPTaa), configured to be reflected by the a first light incident surface (FRaa) of the first optical structure (OPTaa), and then configured to be refracted by a first light exit surface (FRab) of the first optical structure (OPTaa), and wherein the second beam (Rlba) is configured to be refracted by a second light incident surface (FRaa) of the second optical structure (OPTba), configured to be reflected by a second reflection surface (RFba) of the second optical structure (OPTba), and configured to be refracted by a second light exit surface of the second optical structure (OPTba). a first optical structure (OPTaa) configured to refract and reflect a first beam (Rlaa) input from a first direction to output a second beam (Rlba) to a second direction with a width smaller than a width of the first beam (Rlaa); and a second optical structure (OPTba) configured to refract and reflect the second beam (Rlba) from the first optical structure to output a third beam (Rlca) to the first direction with a width greater than the width of the second beam, wherein a height of the first optical structure (OPTaa) and a height of the second optical structure (OPTba) are the same, wherein a width of the first beam (Rlaa) and a width of the third beam (Rlca) are the same, wherein the first optical structure (OPTaa) comprises a first reflection surface (RFaa) configured to reflect the first input beam, wherein a first angle between the first reflection surface (RFaa) and the second beam (Rlba) and a second angle between an orthogonal surface orthogonal to the first beam (Rlaa) and the first reflection surface are each greater than 0° and smaller than 45°, wherein a third angle between a second reflection surface (RFba) of the second optical structure (OPTba) and the second beam (Rlba) is identical to a fourth angle (θ1a) formed by the first reflection surface (RFaa) of the first optical structure (OPTaa) and the second beam (Rlba), wherein the first beam (Rlaa) is configured to be refracted by a first light incident surface (FRaa) of the first optical structure (OPTaa), configured to be reflected by the first reflection surface (RFaa) of the first optical structure (OPTaa), configured to be reflected by the a first light incident surface (FRaa) of the first optical structure (OPTaa), and then configured to be refracted by a first light exit surface (FRab) of the first optical structure (OPTaa), and wherein the second beam (Rlba) is configured to be refracted by a second light incident surface (FRaa) of the second optical structure (OPTba), configured to be reflected by a second reflection surface (RFba) of the second optical structure (OPTba), and configured to be refracted by a second light exit surface of the second optical structure (OPTba).