Rotary shutter assemblies for imaging photometers and methods for using such shutter assemblies

A method for capturing an image measurement from a light source with an imaging photometer, the photometer including a rotary shutter having an aperture, one or more filters, and an image sensor having an array of pixels, the shutter and one or more filters being positioned along an optical axis between the light source and the image sensor, the method comprising:

• rotatably moving the shutter at a generally constant rotational velocity from a first position where the shutter blocks light traveling along the optical axis toward the image sensor to a second position with the aperture aligned with the optical axis such that at least a portion of the array of pixels is exposed to light traveling along the optical axis;
• passing the light traveling along the optical axis through one or more color filters after the light passes through the aperture and before the light impinges upon the image sensor;
• passing the light traveling along the optical axis through one or more neutral density filters after the light passes through the one or more color filters and before the light impinges upon the image sensor;
• and
• rotatably moving the shutter at the rotational velocity to a third position with the aperture out of alignment with the optical axis such that the shutter blocks light traveling along the optical axis toward the image sensor after exposing each portion of the array of pixels to the light for a desired exposure time.

A method for capturing an image of a light source with an imaging photometer having an image sensor with an array of pixels, the method comprising:

• rotatably moving a rotary shutter having a first aperture and a second aperture at a first generally constant rotational velocity from a first position where the shutter blocks light traveling from the light source along an optical axis to the image sensor to a second position such that the first aperture is aligned with the optical axis and the entire array of pixels is exposed to light traveling along the optical axis;
• directing the light traveling along the optical axis through one or more color filters after the light passes through the first aperture and before the light impinges upon the image sensor;
• directing the light traveling along the optical axis through one or more neutral density filters after the light passes through the one or more color filters and before the light impinges upon the image sensor;
• exposing the image sensor to the light for a desired exposure time;
• and
• rotatably moving the shutter at the first rotational velocity to a third position where the first aperture is not aligned with the optical axis and the shutter blocks light traveling along the optical axis.