Items with no label의 주제 Re: Focal length and view angle

Focal length and view angle

YLi75 — Thu, 16 Feb 2017 18:49:13 GMT

Hi,

I understand that the color camera has fixed focus, but I am unable to find any information about the focal length and view angle from the data sheet. What is the color camera's focal length for SR300 and for R200? Thank you.

Re: Focal length and view angle

YLi75 — Thu, 16 Feb 2017 19:11:10 GMT

I can find the field of view for r200 but not sr300. Are they the same?

Re: Focal length and view angle

MartyG — Thu, 16 Feb 2017 19:33:29 GMT

My research indicated that the focal length of the RealSense cameras need to be ascertained with scripting, and there is not a one-size-fits-all set of figures.

For SR-300, try using the instruction QueryColorFocalLengthMM. Intel support staffer David Lu said to somebody else that asked about focal length that this instruction does not work with R200, and for the R200 you should use QueryColorFocalLength (i.e without the MM on the end) instead.

https://software.intel.com/sites/landingpage/realsense/camera-sdk/v1.1/documentation/html/querycolorfocallengthmm_device_pxccapture.html QueryColorFocalLengthMM

https://software.intel.com/sites/landingpage/realsense/camera-sdk/v1.1/documentation/html/querycolorfocallength_device_pxccapture.html QueryColorFocalLength

Regarding field of view (FOV), David Lu states that for the R200, "The FOV is 77°x43°x70° (Cone) for color camera and 70°x46°x59° (Cone) for IR camera." An Intel PowerPoint presentation about the R200 backed this up.

There seems to be disagreement online about how to interpret the FOV for SR-300, with people giving different values. So I will post the FOV data from the SR-300 data sheet.

Re: Focal length and view angle

YLi75 — Thu, 16 Feb 2017 23:21:36 GMT

Thank you for your reply. That's very helpful.

Why do you say that there is not a one-size-fits-all set of figures. Will the focal length varies for different configurations?

Re: Focal length and view angle

MartyG — Fri, 17 Feb 2017 00:08:41 GMT

RealSense expert Samontab reckoned that it was because each camera's "intrinsic matrix" is slightly different due to the manufacturing process. He writes about the subject in these interesting forum threads.

https://software.intel.com/en-us/forums/realsense/topic/612041 Intrinsic parameter

https://software.intel.com/en-us/forums/realsense/topic/644068 R200, SR300 Camera matrix