Patent Number: 
Section: claims

1. An instrument for assaying radiation, comprising:a radiation sensor;a collimator covering at least a portion of the radiation sensor, wherein the collimator defines a first field of view to the radiation sensor; andan insert in the collimator, wherein the insert defines a frustoconical inner shape and a through bore to define a second field of view to the radiation sensor that is less than the first field of view, wherein the insert is located between the collimator and the radiation sensor. 2. The instrument as in claim 1, wherein the radiation sensor comprises an attenuation layer between a plurality of radiation sensitive film layers. 3. The instrument as in claim 1, wherein the first field of view is greater than 60 degrees. 4. The instrument as in claim 1, wherein the second field of view is less than or equal to 60 degrees. 5. The instrument as in claim 1, wherein the insert is connected to the collimator by a material that is transparent to radiation. 6. The instrument as in claim 1, further comprising a camera aligned with the radiation sensor. 7. The instrument as in claim 1, further comprising a dosimeter aligned with the radiation sensor. 8. An instrument for assaying radiation, comprising:a plurality of radiation sensors;a separate collimator covering at least a portion of each of the plurality of radiation sensors, wherein each collimator defines a first field of view; anda separate insert in each collimator, wherein each insert defines a frustoconical inner shape and a through bore to define a second field of view that is less than the first field of view, wherein each insert is located between each collimator and at least one of the radiation sensors. 9. The instrument as in claim 8, each radiation sensor comprises an attenuation layer between a plurality of radiation sensitive film layers. 10. The instrument as in claim 8, wherein the first field of view is greater than 60 degrees. 11. The instrument as in claim 8, wherein the second field of view is less than or equal to 60 degrees. 12. The instrument as in claim 8, wherein the first field of views of the separate collimators overlap one another. 13. The instrument as in claim 8, further comprising a camera aligned with at least one of the radiation sensors. 14. The instrument as in claim 8, further comprising a dosimeter aligned with at least one of the radiation sensors. 15. An instrument for assaying radiation, comprising:a radiation sensor; andmeans for collimating the radiation into the radiation sensor, wherein the means for collimating the radiation into the radiation sensor comprises a collimator covering at least a portion of the radiation sensor and an insert in the collimator, wherein the insert defines a frustoconical inner shape and a through bore and wherein the insert is located between the collimator and the radiation sensor. 16. The instrument as in claim 15, wherein the means for collimating the radiation into the radiation sensor defines a first field of view to the radiation sensor that is greater than 60 degrees. 17. The instrument as in claim 16, wherein the means for collimating the radiation into the radiation sensor defines a second field of view to the radiation sensor that is less than or equal to 60 degrees. 18. The instrument as in claim 15, further comprising at least one of a camera or a dosimeter aligned with the radiation sensor.