individual components will now be described with reference to fig1 . ir1 - ir5 are light projecting elements each made of a light emitting diode for emitting far infrared light . these light projecting elements ir1 - ir5 are arranged in a row in front of a camera ( not shown ). ls1 is a light projecting lens for projecting the light from each of the light projecting elements ir1 - ir5 to form corresponding irradiation beams traveling in different directions . the light projecting elements ir1 - ir5 and the light projecting means ls1 constitute projecting means . em is a light projecting circuit acting as light - quantity control means which controls the light emission of the light projecting elements ir1 - ir5 . pt is a light receiving element of a plurality of photodiodes which receive the reflected light from each of subjects sb1 and sb2 to be photographed to provide an output signal corresponding to the point in its longitudinal direction at which light is received . this light receiving element pt is disposed in front of the camera . ls2 is a light receiving lens for focusing the reflected light from the subject on the light receiving element pt . dt1 and dt2 are detecting circuits for detecting the output signals of the light receiving element pt . op is an arithmetic circuit for providing an output signal corresponding to the distance to the subject on the basis of the output signals of the detecting circuits dt1 and dt2 . ad is an a / d converting circuit for converting the output signal of the arithmetic circuit op from analog to digital form to provide a range value . cr is a main control circuit for controlling the whole system . lc is a lens control circuit for controlling the position of the lens of the camera in response to the distance information from the main control circuit cr . when a release switch ( not shown ) is depressed , a control signal is sent from the main control circuit cr to the light projecting circuit em , so that the light projecting elements ir1 - ir5 successively emit light in time - sharing manner . fig2 , and 4 show light emission patterns of the light projecting elements ir1 - ir5 . describing the relationship between the light projecting elements ir1 - ir5 and the subjects sb1 and sb2 , as will be appreciated from fig1 among the light projecting elements , generally , marginally - arranged ones handle the distance measurement of the subject sb1 positioned close to the camera , whereas centrally - arranged ones handle the distance measurement of the subject sb2 positioned remote from the camera . when the subject is positioned close to the camera , the irradiation beam is only weakened to a small extent and impinges on the subject with sufficient intensity and thus is not influenced significantly by noise or variation . therefore , it is possible to make the quantity of emission light of a marginally - arranged light projecting element smaller than that of a centrally - arranged one , whereby the total amount of power consumption can be reduced . the control example of fig2 is such that the number of times of light irradiation of a marginally - arranged light projecting element is smaller than that of a centrally - arranged one . that is , the total time of light irradiation of a marginally - arranged light projecting element is shorter than that of a centrally - arranged one . the control example of fig3 is such that during times when the light emission of one light projecting element is suspended , another element is caused to emit light , whereby the time interval of distance measurement can be shortened . the signals may be pulsatory as illustrated with pulses of one element being interleaved with those of another element . the control example of fig4 is such that the strength of irradiation light of a marginally - arranged light projecting element is weaker than that of a centrally - arranged element . the control examples of fig2 through 4 may be combined . in operation , the irradiation beams projected from the light projecting elements ir1 - ir5 toward the subjects , after reflection from the subjects , are received by the light receiving element pt . the light receiving element pt provides an output signal corresponding to the point thereon in its longitudinal direction that receives light , the output signal being detected by the detecting circuits dt1 and dt2 . the arithmetic circuit op processes the output signals of the detecting circuits dt1 and dt2 . such processing is performed every time each of the light projecting elements ir1 - ir5 emits light . each calculation result is converted in the a / d converting circuit ad from analog to digital form and then sent to the main control circuit cr as a range value . in the main control circuit cr , a set of range data in digital form corresponding to each of the light projecting elements ir1 - ir5 is averaged , and the smallest value among the thus averaged values is considered as a real distance value . that is , where there are a plurality of subjects in relation to the light projecting elements ir1 - ir5 , the distance to the subject positioned most close to the camera is chosen . the lens control circuit lc controls the position of the lens of the camera on the basis of the distance data given from the main control circuit cr . in this way , focusing is automatically made to the subject positioned closest to the camera . the multi af type range meter according to the invention is made such that the quantity of irradiation light of a marginally - arranged light projecting means is smaller than that of a centrally - arranged one ; therefore , the amount of power consumption can be reduced as compared with the conventional multi af type range meter . further , where the number of times of light irradiation of a marginally - arranged light projecting means is made smaller than that of a centrally - arranged one , the total time for making a distance measurement can be shortened . although the present invention has been described through specific terms , it should be noted here that the described embodiment is not necessarily exclusive and that various changes and modifications may be imparted thereto without departing from the scope of the invention which is limited solely by the appended claims .