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I just recently got the Rebel EOS T3I that came with two lenses (EF 75-300 /4-5.6 III and EF-S18-55 /3.5-5.6 IS II).  When I have either lens set in MF, it takes pictures no problem...When I have the lens set on AF and try to take a picture, it'll either just auto focus and not take a picture at all or I have to hold the button down while it focuses and THEN it finally takes a picture....


What am I doing wrong?


Also, I'm visually impaired and would like to get a downloadable version of the manual....Where can I find it?


Thanks in advance...





The right way is to half press until the AF locks on & then finish pressing to take the photo. Sometimes there isn't enough light or contrast for the AF to lock so you may need to try another area of the scene to get an AF lock. Pressing without having the AF started will lead to missed shots. Once you get used to doing it correctly it will be automatic.


Re manual, click on CANON logo at the top of the page here, then at the top of the page that opens click on Support & Drivers, click your way through the menu boxes & you will end up where the manual can be downloaded as a pdf.

"A skill is developed through constant practice with a passion to improve, not bought."


When the camera is in "One Shot" mode it uses "Focus Priority"

when the camera is in "AI Servo" mode it uses "Release Priority"


The difference is that in with "release priority" the camera WILL take the photo when you fully press the shutter button whether the camera had enough time to lock focus or not.


But in "focus priority" mode, the camera will not take the shot (even when you completely press the shutter) until AFTER it has been able to lock focus.


This is by design.


If you are shooting action and need the camera to take the shot at the moment you press the shutter, swtich it to AI Servo mode.  Also... it will be able to lock focus faster and in lower light levels if you are using lenses with a low focal ratio.  The 75-300 and 18-55 are consumer grade entry lenses designed to keep costs low, but not designed with high performance in mind (there are many lenses designed with high performance in mind, but they cost more.)


In poor lighting conditions, several flashes have a focus-assist beam or focus-assist light and I believe the pop-up flash on the T3i can be used as a focus-assist light.  This allows the camera to focus -- even if you don't want to use the flash (it can use it just to lock focus and then fire without the flash firing.)


As for the manual, you can find a PDF version of the manual here:

 EOS REBEL T3i / EOS 600D Instruction Manual        

Tim Campbell
5D III, 5D IV, 60Da


Thank you both for replying.....I'm an amatuer photographer that's going from a Fujifilm Finepix to a whole new ballgame with a camera that has interchangable lenses......Taking pictures at the Beep Baseball tourneys is going to be totally different....



There should be a PDF version of the manual with the discs that came with the camera. Do you still have them?