Hello,

In general, it's a bad practice to use a negative Camera Delay. 

The first system parameter you have to understand is the In-to-out latency ( you can find it by going to Preferences / Video Inputs). It specifies the constant delay the system should try to keep between the incoming video and the final output. It must include the hardware buffers of the input card (SDI or HDMI), the software buffers of Aximmetry, and the hardware buffers of the output card.

The recommended practice is to adjust the in-to-out latency to the lowest possible value with which you don't yet get the "Cannot keep latency" error. This value will be a hardware-dependent one, you have to find it manually through trial and error.

Now, the only case you can use negative Camera Delay if there are enough frames pending in the software buffers of Aximmetry. So if you set the in-to-out latency to the lowest possible as recommended, you most likely won't be able to use negative delay without getting the "Cannot keep latency" message.

To summarize: the good practice is using a low in-to-out latency, leaving the Camera Delay on zero, and using a positive Tracking Delay.

HOWEVER: in rare cases, the tracking system has a long processing time that results in having an even greater delay than the camera input. In this case what we recommend is:  first try to use a negative Tracking Delay.  If it is not possible (you get "Cannot keep latency" for the tracking device) then use a positive Camera Delay  (or alternatively increase the in-to-out latency, thus keeping the sync between the camera inputs in the case you use multiple ones).

Best regards,

Hello Ahmed,

That makes sense!

This is the first time I learned that there is an [in-to-out latency] item.

So you only put a negative value in the camera delay if the processing time of the tracking system is long and there is an even larger latency than the camera input.

Thank you very much for your kindness!