Canon 60D Question.

[africanrefugee]

I have just got my new 60D and still getting to know the beast. One thing I have noticed though is that when set to Live View, the camera hunts back and forth trying to focus before eventually focussing, but when viewing through the eyepiece the camera focuses much quicker and surer. What could be the possible reason for this? I have noticed this when using my Tamron 17-50mm f2.8 lens. Both my lenses are Tamron (other an 18-270mm). I am not sure if this could be due to the non Canon lens or a camera setting?

Any ideas anyone?

[OsmosisStudios]

It's because youre using a different AF system when you use Live View. The dSLR was DESIGNED to use the eyepiece for focusing (there's a very complicated, very sensitive AF sensor system in the pentaprism). When you use LiveView you use a more accurate version of what is used on compacts. THAT system is designed for accuracy, not speed, so it sometimes goes in and out to get the best result.

[inkista]

Could be the difference between phase detection and contrast detection autofocus.

As I understand it (I could be wrong. I've kind of got a cold right now and my thinking is sorta fuzzy), phase detection requires that the mirror be down, so it can only be used through the viewfinder. It's much faster than contrast detection (which is what's used in most P&S cameras). Separate sensor arrays are used--these AF sensors are blocked from the lightpath when the mirror's up.

Contrast detection uses the image sensor itself, but is typically slower.

http://www.cambridgeincolour.com/tut...-autofocus.htm

[africanrefugee]

Thanks for the advise. It was just something I noticed on the 60D that was not as apparent on my 450D (not that I used live view on the 450D), and I was hoping it was not a 'fault' of the 60D. I thought it may have also been due to the non Canon lens usage and differences in algorithms but did not know enough to figure it out.

Now that's sorted back to taking pic's (and learning as I go).