PROBLEM TO BE SOLVED: To provide a mechanism capable of calculating the magnification in the entire optical system of an eyeground camera including a subject eye, without requiring optical information on the subject eye beforehand.SOLUTION: An eyeground camera 100 includes a control unit 33. The control unit 33 first brings the eyeground Er of a subject eye E into focus and then cancels the linkage provided by a focus linkage mechanism 25 between focus index projection means 8 and a focus lens 13 moves the focus index projection means 8 on the optical axis from the focused position according to the amount of deviation of the focus index image captured by the focus index projection means 8 while the imaging optical system including the focus lens 13 is focused onto the eyeground Er of the subject eye E and calculate a magnification for the entire optical system of the eyeground camera 100 including the subject eye E, using the amount of movement of the focus index projection means 8 from the focused position.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2017,JPO&INPIT【課題】予め被検眼に関する光学的な情報を必要とすることなく、被検眼を含む眼底カメラの全体の光学系における拡大率を算出することが可能な仕組みを提供する。【解決手段】被検眼Eの眼底Erに合焦させた後に、フォーカスリンク機構25によるフォーカス指標投影手段8とフォーカスレンズ13との連動を切り、フォーカスレンズ13を含む撮影光学系が被検眼Eの眼底Erに合焦している状態で、フォーカス指標投影手段8によるフォーカス指標像のズレ量に応じてフォーカス指標投影手段8の光軸上の位置を合焦位置から移動させる制御を行い、フォーカス指標投影手段8が合焦位置から移動した移動量を用いて被検眼Eを含む眼底カメラ100の全体の光学系における拡大率を算出する制御部33を備える。【選択図】図1
