I'm having trouble with my shutter locking up.

Question

I'm know cameras pretty well...previous post discussed setting but I know what setting & lighting conditions to use. Basically the shutter closes & won't open back up or release unless I turn the camera off & back on. I think I've pinpointed it to be happening when I'm zooming in or out with my lens & trying focus. This is not good seeing as I do mostly sports photography! Asking if you think this is a camera/lens flaw or operated error. I'm use to my Nikon & never had this problem before....and anyone else I talk to loves their Canon. Help!

Answer 1

If the camera has a "focus lock" or "focus trap" setting, you must turn it off. I don't know if a T3 has that feature, though.
If the sports involve any sort of movement, you have to use AI Servo focus, not One Shot. One Shot is only for stationary subjects. In One Shot mode, as soon as focus is achieved, auto focus stops and locks. If a subject is moving, it will go out of focus and One Shot cannot correct for that. AI Servo, on the other hand, focuses continuously, as long as you keep the shutter button half-pressed and an active AF point on the subject you want focused. It never stops and locks, the way One Shot does.
In order to better understand the AF system of Canon cameras, I recommend viewing three half hour videos on YouTube, beginning with this one.  These videos cover a variety of Canon camera models and there are some differences between them, but you will likely find info relevant to your camera.
Besides focus, there are other possiblities... However, first thing to note is that the shutter doesn't close when you press the shutter release button, it opens. The shutter is normally closed, only opens momentarily to make the exposure. If you are seeing the viewfinder go dark (which is due to the mirror flipping up, not because "the shutter is closing") and no image is being taken, there are a couple things to check....
1. Do you have "mirror lockup" engaged? This feature is on most Canon cameras I'm aware of and is turned on in the menu. It's used to flip the mirror up in advance of taking a longer exposure, where the vibration of the mirror "slap" might cause shake blur in the image. Once it's engaged, you press the shutter release once to raise the mirror, then a second time to take the image.
2. Have you accidentally put the camera into Live View mode? This lifts the mirror immediately and what's being seen  via the lens is then displayed on the camera's rear LCD screen, real time. Accidentally starting Video recording acts similarly.
3. Long exposure noise reduction is another feature that can be enabled or disabled on many Canon. It doesn't sound as if you are using long exposures, however just so you know, when LENR is on, the camera actually takes two images. First is the long one you set up, the second is equal length but with the shutter closed... a "dark image" that's used to identify noise to be deducted from the first image. Problem is, if you don't realize what's happening and cancel the second image (by turning off the camera, for example), neither the second or first images are saved. So you end up wondering what happened to your shot. But, again, this is not likely to be what you are encountering, because it sounds as if you are shooting in good light and using fast shutter speeds where LENR wouldn't occur, even if it's turned on.  
I wouldn't worry about using higher ISO... 400 is about the lowest I use with sports shooting, unless I am going for slow shutter speeds and "action blur" effects. You should try 800 and even 1600. If shooting in the shade, I'll sometimes use 1600 even in broad daylight.
I would steer clear of Full Auto and Sports modes. Instead I'd suggest using P or, even better, Tv. These are still full auto exposure modes, but they don't impose other limitations on you (such as forcing you to shoot JPEGs instead of RAW files, and/or limiting the focus modes you can select).
Hope this helps!
Alan Myers
San Jose, Calif., USA
"Walk softly and carry a big lens."
GEAR: 5DII, 7D(x2), 50D(x3), some other cameras, various lenses & accessories
FLICKR & PRINTROOM