where there’s smoke there’s fire

Patent 2010-224290 is for a light meter built into the prism (for use during video recording?):

“This invention relates to the camera which has a photometry sensor which measures the strength of the light with the light led to the optical finder and the optical finder.

Problem to be solved: to make effective use of a photometry sensor.

Solution: Since subject luminous flux is not led to an optical finder in a mirror up state, TTL photometry is not performed by the photometry sensor 8 provided in the finder. However, by changing an angle of a movable mirror 6, the subject luminous flux is led to the photometry sensor 8 from a photometry window 51 provided on a front surface of a pentagonal prism cover, so that external photometry is performed. The photometry is continuously performed by holding the movable mirror 6 at an angle where external photometry is performed the external photography can be performed when a live view mode is set or when a moving picture is taken while the mirrors 1 and 9 are held in an up state.

While enabling observation of a photographic subject by leading the object light bunch which penetrated the taking lens to a finder optical system by a main mirror with a single-lens reflex camera, it is common to receive the light led to the finder optical system with a photometry sensor, and to obtain photographic subject luminosity

The photometry sensor is only used for the conventional single-lens reflex camera as a TTL photometry sensor, and it does not aim at effective use of a photometry sensor.” (machine translated)

Read More »