Friday, June 16, 2017

Most accurate FPV cam latency test method? and: eliminate interference in your downlink video

2020 UPDATE: "current" Latency XLS Sheet



My most accurate FPV Cam latency test setup:

2 channels (curves on osci):
ch A = video signal (NTSC)
ch B = 12v powersource for my LEDs   (I think I dont measure the actual switch on, but rather the time when it "consumes" the 12v. Would be interesting to know how much time does it take the LED to light up?)

Measure the delay from LED switch and the "effect" from a dark cam image to a RED LED light screen (noticable effect on the video curve).
This way we still have the 17ms steps of time resolution since we only see 60fps on NTSC. So we cant measure cam latency more accurate than in 17, 34, 51ms...
BUT: until now I used a LCD screen to read the VIDEO signal changes (and the screen also runs a certain FPS - so this is not accurate anymore - better to "read" the video signal directly without a LCD).

FPV Cams Latency overview:  (June-2017)     (also available as XLSx File)





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