Help W/Adjusting Camera Focus on Canons?

**WaistDeepGroomers** · 10-03-2014, 12:01 AM

Yo yo,

So I have been shooting a bit of photos on this bike trip up in BC, but keep having issues with getting the subject in focus. Borrowed a 7D for the trip and whether I'm in auto focus or using the manual focus, I'm having a real hard time getting the biker in focus, and mostly seem to end up photos where the immediate foreground is the part in focus. See below:

Last time, I noticed there was a little scroll roller on the right of the viewfinder that I was told you can adjust depending on your stigmatism issues. I don't really have any vision issues, but still when I think I have focused on the spot where the action will take place, the photos turn up with the foreground in focus instead. Only other factor I can think of is that shooting in the thick forests here, the depth of field is pretty tiny, can't get a decent shot off above 2.8 or 5, but still that wouldn't influence where the camera ultimately focused, right?? Been using the grid mode to to change around where the camera is centering its focus.

**geomorph** · 10-03-2014, 05:02 AM

One thing to try is to give the autofocus sensor a clean with a rocket blower. It's the set of square holes on the bottom when you are looking at the mirror. I was having trouble with focus below 2.8 and cleaning fixed that. Otherwise, you might have your micro focus adjustment set to something funny. For the manual focus, yeah maybe the diopter needs adjustment.

**systemoverblow'd** · 10-03-2014, 08:13 AM

To check diopter, put it on legs, manual focus in live view and take the picture. Then look through the view finder, is it in focus? Then defocus and then use auto focus. Again, look through the viewfinder and see if it looks in focus. Do this in live view and no live view (different focus system I believe). Then compare all three images in an editing app. By doing these steps and figuring what happens in each can determine if the lens needs micro adjusting, the auto focus system is wonky, if the diopter needs adjusting etc. There are way too many variables to answer online without a battery of tests. I can suggest something but without knowing how the camera performs in these scenarios, it's a crap shoot. And you say your eyes aren't bad... What about your friends whose camera it is? Do they own the same lens and micro adjusted for their copy?

PS... Can't even tell if you missed focus, had hand shake, or shooting too low shutter speed because I can't view the pics on Mt android still...

**::: :::** · 10-03-2014, 09:38 AM

are you isolating the focus target to only one of the focus sensors?

**systemoverblow'd** · 10-03-2014, 09:54 AM

read this: http://www.dpreview.com/forums/post/41802462

**mtcham** · 10-03-2014, 12:07 PM

So what happens when you focus on a non moving object and take a pic? Is it sharp where you expect it to be, or is it front focusing? If sharp then it's most likely your technique. Are you shooting while panning on the biker or waiting for him to enter the prefocused frame? Are you in continuous servo mode single point or a different AF mode?

Your second shot I could understand some focus lag if you are tracking him and you don't have a fast focusing lens. The first shot doesn't make as much sense but you may have picked up a focus point on the near right side as he was coming around the turn.

You also may be getting motion blur if your shutter speed is not high enough. My old eyes would need a high rez pic to see the sharpness better.

Should be pretty easy to figure out.

**WaistDeepGroomers** · 10-05-2014, 06:07 PM

Hey guys,

Thanks for all the help. Will have to spend some time doing some tests to diagnose, Tye1on also mentioned a mode where the camera will focus on an area of the frame vs. one tiny spot, which I've since read has a hard time dealing with moving subjects and focusing sharply. Had some slightly better results the past few days but still need to spend some time actually learning this stuff vs. sitting in the woods and cursing and flipping the dials around. Thanks mags.... and system, I'll ping the tech team again on the android issues.