Focusing question

[HeatherM]

Forgive me if this is an elementary question. I understand that in order to get the best focus, the center focus point should be selected. I also understand that the focus-recompose method has its faults. So, how do you make a pleasing composition and still use the center focus point?

[prncfarquad]

I don't think that center point is a must to achieve good focus. Spot focusing with any of the focus points will help ensure good focus but it doesn't have to be the center one.

I am not sure on the rebel but on my 7D and 1D but I can change the settings on my camera where the shutter release button doesn't start focus but the focus on button on the back does. So I can set to center point, hit my focus button on the back, recompose and shoot.

With that said I have heard arguments for and against this method but it works for me 99% of the time.

[HeatherM]

Originally Posted by prncfarquad

I am not sure on the rebel but on my 7D and 1D but I can change the settings on my camera where the shutter release button doesn't start focus but the focus on button on the back does. So I can set to center point, hit my focus button on the back, recompose and shoot.
With that said I have heard arguments for and against this method but it works for me 99% of the time.

I've heard about using the back * button to focus, but I'm not sure I fully understand the advantage. Does it lock the focus?

[princer7]

Yes. It locks the focus. Press and release - keeps the focus from changing unexpectedly as you press the shutter button. It can also be used by continually holding it down when tracking a moving subject.

http://www.learn.usa.canon.com/resou..._article.shtml

[HeatherM]

Very cool. Thanks!

[mmuhlenkamp]

I also use the back-button focusing like Patrick described, I think it helps a lot. It takes some getting used to (and makes it nigh impossible for anyone else to use my camera), but I like it a bunch.

[Tom]

I only use back button. With my 5D2, I only use the center point. 1D3 and 7D, I will use outer points. Focus and recompose on all cameras.

[HeatherM]

Thanks for all the responses! It's going to help out a lot.

[Stargazer77517]

+ 1 Same way for me also.

Originally Posted by prncfarquad

I don't think that center point is a must to achieve good focus. Spot focusing with any of the focus points will help ensure good focus but it doesn't have to be the center one.

I am not sure on the rebel but on my 7D and 1D but I can change the settings on my camera where the shutter release button doesn't start focus but the focus on button on the back does. So I can set to center point, hit my focus button on the back, recompose and shoot.

With that said I have heard arguments for and against this method but it works for me 99% of the time.

[Nikonfan]

Originally Posted by HeatherM

Forgive me if this is an elementary question. I understand that in order to get the best focus, the center focus point should be selected.

I have heard that Canon's tend to have issues with back focusing or front focusing if you use a focus point other than the center. I have always wondered if that is true or not. Your comment has me wondering about that again. Does anyone know the answer to that? And no, I am not trying to start a Nikon vs Canon war. Just curious if there is any merit to the above issue.

[Hanky]

Originally Posted by mmuhlenkamp

I also use the back-button focusing like Patrick described, I think it helps a lot. It takes some getting used to (and makes it nigh impossible for anyone else to use my camera), but I like it a bunch.

I love BF except when I'm with the wife and someone takes out picture. Our guy was manually focusing my new 24 mm lens and my insides cried out in horror. Not sure it is something that can be explained to a non shooter with my limited communication skills.

[ngoduyviet]

Center (cross) focus point(s) with lenses faster than 2.8 tend to be better but not necessarily a must. You can do a focus lock & recompose, or if given time, choose the focus point closest and shoot away.

[Nikonfan]

Really? That's very interesting. Any idea why the faster lenses seem to have a harder time focusing? Also, is it only when they are wide open or do the faster lenses seem to have a harder time regardless of the f-stop?

[ngoduyviet]

Originally Posted by Nikonfan

Really? That's very interesting. Any idea why the faster lenses seem to have a harder time focusing? Also, is it only when they are wide open or do the faster lenses seem to have a harder time regardless of the f-stop?

I think you have it backward. Faster lenses allow more light in and help a lot with focusing. Your camera always focuses with your lens wide open, does not matter what F stop you choose. Then it'll close down to your F stop when you press the shutter button.

Canon fuzzy technology wasn't as good a while back and their cameras suffered focus problems in dark environment hence the needs for focus assist light on the body & on-board flash.

Higher end cameras don't have this problems (anymore). Also if I remember correctly, center cross-focus points were designed to be more sensitive & better focus track than the ones around.

[J Eddington]

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