Lens 'hunting'

[botty1963]

I've noticed over the last few months that my Canon 24-105 lens has on occasions struggled to find focus even when there is plenty of contrast in the photo. It seems to do it for a few seconds then manages to lock on. I haven't intentionally changed any camera settings that might affect it, but just wondered if there are any in my 7D that could cause this that I may have unintentionally changed.

[Shadowman]

I've noticed over the last few months that my Canon 24-105 lens has on occasions struggled to find focus even when there is plenty of contrast in the photo. It seems to do it for a few seconds then manages to lock on. I haven't intentionally changed any camera settings that might affect it, but just wondered if there are any in my 7D that could cause this that I may have unintentionally changed.

Hi Steve,

Does this only occur when handholding? Try it on a tripod.

[Manfred M]

Focus seeking occurs when the camera is given a scene and it can't determine what the subject is. I find that this is more an issue on longer focal lengths.

The simplest solution is to change the focus mode, I usually use a technique of "focus and recompose" where I set a single focus point on the camera, get focus (and exposure). If your camera is using a standard setup, this will happen when you depress the shutter release half way. Once you have focus lock, then keep the shutter release pressed halfway and reframe the image in your viewfinder to the composition you like, before pressing all the way down on the shutter release.

I use this technique in virtually all shooting situations where there is little movement in the image (for me, this is 99% of the time). I will only go to a more complex focus mode when the action is moving towards or away from me.

This technique takes a bit of time to get used to it, but once you learn it, you'll find that you use it a lot because of the fast and accurate focus it gives you.

[DanK]

I haven't intentionally changed any camera settings that might affect it, but just wondered if there are any in my 7D that could cause this that I may have unintentionally changed.

How many focus points are you using? The more focus points you are using, the more high-contrast locations the camera is likely to find. At least as a diagnostic, if you are using more than one, set it to single-point and see if the problem is reduced.

[William W]

I've noticed over the last few months that my Canon 24-105 lens has on occasions struggled to find focus even when there is plenty of contrast . . . It seems to do it for a few seconds then manages to lock on. . . just wondered if there are any in my 7D that could cause this that I may have unintentionally changed.

1. What AF point(s) is/are selected?
2. What AF Mode is selected (specifically - including AF Expansion and Custom Functions)?
3. What Camera Mode is selected?
4. Are these scenes backlit?
5. Does this happen with any other lens?

WW

[William W]

As I was writing (and drinking coffee) Dan K beat me to the endgame - that's where I was heading.

WW

[botty1963]

Thanks as always guys, I'll have a quick look over the weekend. Heading off back to Iceland on Tuesday for 7 days so don't want to miss opportunities as my camera struggles to make it's mind up like a lady selecting new clothes

[NorthernFocus]

Thanks as always guys, I'll have a quick look over the weekend. Heading off back to Iceland on Tuesday for 7 days so don't want to miss opportunities as my camera struggles to make it's mind up...

For landscape shooting there's always manual focus.

... like a lady selecting new clothes

Ladies, comments? Izzie, Binnur, Christina, Tejal?

[botty1963]

Yep, manual and tripod for lots throughout the trip, but autofocus for general hiking and visiting

[benm]

botty1963, has this problem progressively worsened over those months? If so, maybe there is some dust obscuring the AF sensors. Try blowing out the mirror box (carefully) and see if that helps.