Magic Lantern Forum

Using Magic Lantern => General Help Q&A => Topic started by: SD on July 26, 2012, 01:58:12 PM

Title: Cycle time on Trap Focus in ML 2.3 rc1 50D
Post by: SD on July 26, 2012, 01:58:12 PM
I am interested in improving the cycle time in Trap Focus on the 50D.  After the Trap Focus has taken a picture it takes a second or so to reset, it seems.  I am interested in improving this performance.

First, is the cycle time an issue of the 50D, for example if I get a 60D will it improve?  Or is it something in Magic Lantern? Or it is inherent in the Canon focus assessment system independent of camera model?


Here is a short video showing it in action.  At around 50 seconds in the video the green car triggers the shutter but it does not reset fast enough for the black car following it.

Trap focus on vimeo (http://vimeo.com/46421325)


Thanks in advance for any ideas.


Title: Re: Cycle time on Trap Focus in ML 2.3 rc1 50D
Post by: a1ex on July 26, 2012, 01:59:04 PM
You can also setup a dummy bracket - to take 3 pictures for each focus confirmation, for example.
Title: Re: Cycle time on Trap Focus in ML 2.3 rc1 50D
Post by: SD on July 26, 2012, 02:10:20 PM
Thanks, but that does not really work for this application.  This will get me the second car but then if there is a third car close enough behind you do not reset fast enough for that. 








Title: Re: Cycle time on Trap Focus in ML 2.3 rc1 50D
Post by: a1ex on July 26, 2012, 02:16:36 PM
It's still slow with image review off, right?


                lens_take_picture(64,0);
                if (trap_focus==2) // engage half-shutter for next shot
                {
                    if (image_review_time) msleep(2000);
                    SW1(1,0);
                }


So, the best you can do is to replace lens_take_picture with a simple call("Release") and comment out the waiting part.
Title: Re: Cycle time on Trap Focus in ML 2.3 rc1 50D
Post by: SD on July 26, 2012, 02:20:46 PM
I will look into that, thanks. That seems promising.

Edit: OK, that works, the thing sometimes even triggers twice on the same car moving through at 35 mph. pretty good stuff.

I like having image review on to confirm quality and functionality in a long session.  Is there any reason why ML needs to wait for image review? I am guessing not.
Title: Re: Cycle time on Trap Focus in ML 2.3 rc1 50D
Post by: a1ex on July 26, 2012, 03:06:30 PM
The only reason is a bit of UI consistency - if you have review enabled, you probably expect to see the image.

So, if you turn off review, it's already as fast as you need?
Title: Re: Cycle time on Trap Focus in ML 2.3 rc1 50D
Post by: SD on July 26, 2012, 03:18:54 PM
Yes, without review it is fast enough now. Like I said, two pics of the same car sometimes.  I may now need to put a half second sleep in there.