Author Topic: Trap focus quickness? Or just camera limitations?  (Read 1962 times)


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Trap focus quickness? Or just camera limitations?
« on: May 12, 2017, 07:21:30 PM »
Hi! Last weekend I did several tests with Trap Focus. It's an awesome feature and -for me- one of those things that make ML really useful.

Question: I noticed in some shots the Trap Focus wasn't quick enough, firing the shutter when the object was no longer in focus. I'm aware that the DOF was pretty ridicoulous (shooting a car with 85mm f/1.4 in a full frame 6D) and the object was moving in a relatively quick speed. So I think this delay is just due to camera speed limitations. Is that right?

Anyway, thanks for this nice feature. Regards!


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Re: Trap focus quickness? Or just camera limitations?
« Reply #1 on: May 13, 2017, 10:21:47 PM »
Right, the response time isn't the best. Before taking the actual picture, Canon code does a lot of preparations (including taking a dark frame at full width, but reduced vertical resolution, on most models). If you are in LiveView, turning it off takes additional time.

For instant response, you can try the silent picture module with the "Best focus" option. This should work very well for fast moving subjects running towards you, for example (use 50/60 fps if needed). Main issue: resolution.

The 4K branch has the potential to fix the resolution issue (it can take full-res LiveView frames on 5D3, but the focus estimation is not working yet in this mode). Pre-recording with half-shutter trigger can be helpful - it works with full resolution LiveView, but somebody has to port it on the 6D.