My camera cannot reach the published frame rate, why?
mvBlueCOUGAR-X, mvBlueCOUGAR-XD, mvBlueFOX3
There is no simple answer to this question, because there are many reasons for a lower frame rate.
The published frame rates in our datasheets and manuals (e.g. via the frame rate calculator) represent the value which is possible by the sensor in theory. In general, these frame rates are transferred to a PC or application.
However, there are many stations until an image arrives at the PC or in the application. After the exposure of the sensor, the information are digitalized. The information are still in the
Working with "normal" frame rates, there should be no effect while using preprocessing steps like automatic white balance, frame averaging, etc. The higher the frame rates, the higher the chance, that it will effect the frame rate.
Example: The mvBlueFOX3-2024 supports a frame rate of 164 FPS (Figure 1). If you turn on the automatic white balance, the frame rate will fall to 154 FPS (Figure 2):
- Transfer bandwidth
You can check, if the transferred images from a camera are suitable for the bandwidth of the used interface. Especially multicamera application will reach the limits if the cameras have to share one bandwidth.
Example: The mvBlueCOUGAR-X100w support 117 FPS, the net bandwidth of Gigabit Ethernet is approx. 120 MB/s:
117 x 752 x 480 x 8 bit = approx. 42 MB/s
I.e., there is enough bandwidth. However, the bandwidth is not enough for three cameras.
- Components between camera and PC
To share or to extend the transmission path, switches or hubs are used. They are available for Gigabit Ethernet, Dual Gigabit Ethernet as well as for USB 3.0. It is also possible that there are limits because of the hardware. Is the firmware up-to-date, does the Dual Gigabit Ethernet switch support Link Aggregation, is there enough internal memory, to buffer or to process the data, are questions you have to ask.
- Components in the PC
The PC connections can also be a source for frame rate losses. For example, front connections have a worse linking to the motherboard. Old or buggy drivers can also be a reason for frame rate losses. Please check, how the cameras are connected.