Why are you multiplying by the image height? That gives you the frame period (1/frame rate), not the minimum exposure time.
As rpicam-hello --list-cameras will tell youmin value of V4L2_CID_VBLANK is 58 in the full res mode.
26.522 * (2592 + 58) = 70283.3usec = 70.283ms
1/0.0702833 = 14.22fps (not quite sure why that number isn't matching the 14.35fps reported by rpicam-hello)
As stated in that other thread,
Being a rolling shutter sensor, there will be a temporal shift between the exposure for each line in the image.
As rpicam-hello --list-cameras will tell you
Code:
0 : imx708 [4608x2592] (/base/soc/i2c0mux/i2c@1/imx708@1a)Modes: 'SRGGB10_CSI2P' : 1536x864 [120.13 fps - (768, 432)/3072x1728 crop]2304x1296 [56.03 fps - (0, 0)/4608x2592 crop]4608x2592 [14.35 fps - (0, 0)/4608x2592 crop]26.522 * (2592 + 58) = 70283.3usec = 70.283ms
1/0.0702833 = 14.22fps (not quite sure why that number isn't matching the 14.35fps reported by rpicam-hello)
As stated in that other thread,
So the minimum exposure time is 26.522usecs.As IMX708_EXPOSURE_MIN is 1 line, that is the minimum shutter time in that mode.
Being a rolling shutter sensor, there will be a temporal shift between the exposure for each line in the image.
Statistics: Posted by 6by9 — Thu Mar 13, 2025 11:53 am