sirchocolate-teapot wrote in post #12183923
1.Half press shutter button to focus
2.Release shutter button back to it's out position3.Then fully depress shutter button to take photograph
Who told you that step 2 was necessary? You can just remove that from the sequence completely. The actual sequence is to just use steps 1 and 3 - half press the button to focus (and spin up the IS if applicable) then just press a little harder and take the shot when ready.
Step 2 just means that the camera will have to focus again, when you press the button the second time. However, if you are now just doing a full press without a pause at the 'half press' point, the camera may not have time to focus properly before you trip the shutter. If you are using AI servo focusing, the camera needs a pause to assess the focusing as focus is predictive, so it has to be able to calculate the changes in distance over time, and work out where the target will be when the shutter fires, then focus ahead of it to allow it to move into focus. Ideally, with AI servo, you want to track the subject with the button half pressed until it reaches where you want to take the shot(s) then just press the button the rest of the way, so youm don't interupt thye focusing. You can back off to the half press position and then fully press again to take further shots without affecting the focus tracking. Take your finger off and you have to start the focusing all over again.
If you should put an IS lens on the camera and shoot your way, it will screw up your shots, as the half press also spins up the IS system and it takes it a few moments (up to a second with some lenses) to stabilise. It will do that whilst you hold the shutter at half press, but if you use step 2 and take your finger off, it will shut the IS down again. If you then suddenly press the shutter the whole way from that position, the shot will be taken with the IS jumping into life and still trying to settle down. That will likely introduce an effect similar to camera shake.