I JUST CAN'T NAIL MY FOCUS! I'M SO FRUSTRATED!

[MTVision]

With every 50mm 1.8 there should be directions to go immediately to a forum for instructions because everyone ends here eventually. ]

^^^^ that's funny!

 

[vtf]

Using the information from your shots you will have .37 feet of focus plane. This isn't terribly bad for a subject that is still and you want focus to fade off quickly behind, but for a moving child I would lower your shutter to 200 or 250 and set aperture at 4 to 5.6. You could go as high as f11 and have a foot of focus, as long as the background is some distance away it should still blur but around f4 or so is better.
Also, do you shoot in RAW, I think the posted shots need just a tad sharpening.
One last detail, when photographing children or animals, get down to their world, lie on the ground if you have to, you'll have an amazing perspective of what your children see and we have forgotten.
:thumbup:

 

[vtf]

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You can definately see the benefit of flash, top 2 vs. bottom 3. Utilizing flash will make the adjustments simpler.

 

[KmH]

With every 50mm 1.8 there should be directions to go immediately to a forum for instructions because everyone ends here eventually. The sweet spot for the 50mm is f4 to f6.3. At f1.8 and 5 feet away the plane of focus is merely .2 feet. On a moving child your minimum shutter speed should be 200. This is why I shoot manual so I can have control.
This may help some.
Online Depth of Field Calculator

Right on!

FWIW: .2 feet = 2.4 inches, and the way DoF works roughly 1/2 of that, 1.2 inches is in front of the focus point and the other roughly 1/2 is behind the focus point.

The OP's biggest problem is she doesn't yet have even a rudimentary understanding of the technical aspects of doing photography with a DSLR camera.

Here is a great group of digital photography technical tutorials: Digital Photography Tutorials

To do photography well will require a good, solid, basic understanding of most of the subjects in that list of tutorials.

 

[Neiby]

Noob question here: how does using back-button focus help? My 60D has that option, but I haven't tried it yet. I can quickly set it so that the back button does AF and the front only sets exposure instead of using one for both, but it's not immediately clear to me how this would improve focusing.

 

[MTVision]

Noob question here: how does using back-button focus help? My 60D has that option, but I haven't tried it yet. I can quickly set it so that the back button does AF and the front only sets exposure instead of using one for both, but it's not immediately clear to me how this would improve focusing.

"With back button focusing you are seperating focus from the shutter button. Say you have a stationary object - you use BBF to lock focus where you want it (you don't even have to hold the button depending on your settings - just hit it once) and you can keep taking shots without refocusing. You can recompose the shot easier - without losing focus to an extent. BBF basically locks focus.

Back Button Focusing | Tutorials @ RKP

Choose your fastest lens (your nifty fifty will be perfect for this) and set it to its largest aperture. Place a few things (3-4 small objects like coffee mugs will work) at different places on an uncluttered table. Vary the distance of the objects to you and your camera, but be sure to place them so that they’ll all fit in your camera viewfinder. The next steps describe the focus/recompose technique so if you’re already familiar, get to it.
Get as close as you can to your minimum focusing distance and center the closest object in your frame. Press the back button to focus on it. Use the shutter button to activate your meter and dial in proper exposure, but don’t take the picture yet. Once that’s done, recompose the image so that one of the other objects is centered in your viewfinder, but make sure that the original object is still in the frame. Don’t refocus! Now, take the picture.
The object that you originally focused on should still have the main focus even though it wasn’t the object in the center of the frame when you pressed the shutter button.
It will take some time to get used to using BBF, but once you do, you’ll wonder how you ever took pictures without it."

 

[MLeeK]

Noob question here: how does using back-button focus help? My 60D has that option, but I haven't tried it yet. I can quickly set it so that the back button does AF and the front only sets exposure instead of using one for both, but it's not immediately clear to me how this would improve focusing.

It separates the metering and shutter action from the focus making focus something you have to do while you aren't concentrating on the scene, meter and settings. It's VERY easy to focus and glance at that meter while you are prepping for a shot and knock out focus without ever knowing it. Keeping the two separate also makes for much more accurate metering in the priority modes.

 

[Neiby]

Thanks, but I still don't get it. lol I already do focus/recompose without the back button. I'm just not getting how moving the focus to a different button helps. I'll read the tutorial you linked to. Maybe the light bulb will turn on in my head.

 

[MTVision]

Thanks, but I still don't get it. lol I already do focus/recompose without the back button. I'm just not getting how moving the focus to a different button helps. I'll read the tutorial you linked to. Maybe the light bulb will turn on in my head.

Yeah but the way you focus and recompose doesn't necessarily lock the focus. You have to keep the shutter pressed halfway down to recompose and there is always a chance the camera will switch focus to something else. With BBF you can hit the button and take more than 1 shot without ever focusing again or hitting the button again. I can hit the back button, lock focus, take the shot and then take a few more without focusing as Lon as the subject hasn't moved.

 

[MTVision]

As for the back button focus, that is something I've been doing for 5 years now. On my older cameras, I set the custom function to all the * button to activate focus, rather than the shutter release button. Now they have added an af-on button back there, which is great.
I wouldn't say that it will give you 'more accurate' focus, it just allows you to separate the focusing from the shutter button, which may mean that you miss-focus less often.

 

[Neiby]

I think I get it...but I don't get it. I just read an article that mentioned a good use case. If I switch to BBF and stay in AI Servo mode, I can keep a focus point on moving objects and make sure I'm staying in focus. However, my noob brain is just not seeing the advantage to it when shooting in one-shot focus mode. If I'm taking multiple shots and recomposing, it seems to make more sense to refocus each time just in case.

Then again, I wonder if this solves a problem I've been running into occasionally. If I focus/recompose, my exposure can be off if I'm in Av or Tv, so I use AE Lock to lock an exposure, then focus and recompose. If I used BBF, I could focus, then half-press the shutter to set exposure, which solves the problem without AE lock, right?

 

[MLeeK]

I think I get it...but I don't get it. I just read an article that mentioned a good use case. If I switch to BBF and stay in AI Servo mode, I can keep a focus point on moving objects and make sure I'm staying in focus. However, my noob brain is just not seeing the advantage to it when shooting in one-shot focus mode. If I'm taking multiple shots and recomposing, it seems to make more sense to refocus each time just in case.

Then again, I wonder if this solves a problem I've been running into occasionally. If I focus/recompose, my exposure can be off if I'm in Av or Tv, so I use AE Lock to lock an exposure, then focus and recompose. If I used BBF, I could focus, then half-press the shutter to set exposure, which solves the problem without AE lock, right?

I can't use back button effectively yet while i am shooting sports. For weddings, portraits and the like? YES. The best thing I can tell you is to play with it and see what it does. Explaining things in type doesn't always come out the way it does by just plain doing it.

Focus and recompose is really a bad habit to use. I know we all do it to a degree, but when you move side to side you really are almost always changing the focal plane. Unless you are shooting with a depth of field of more than 6 inches or close to it you may run the risk of really being able to notice it. Ideally you would toggle to the focus point that falls where you want to lock focus and use that one. That's a lot of buttons to be playing as you are shooting but as with everything-practice makes perfect. It does get to be second nature.
Now with sports I don't toggle at all. I use the middle, lower focus point for football. Middle area for Volleyball, Upper middle for basketball, middle area for wrestling. Why? that puts my subjects where I want them when it comes time to crop the image to standard sizes and it also keeps my field/court/mat balanced and doesn't give me a great gaping expanse of green or yellow or mat.

 

[Neiby]

I've been reading more about this, including on another forum, and I still can't see the benefit for me unless I'm in continuous focusing mode, which I would never be in unless I'm shooting sports. It's kind of hard to focus and recompose in continuous focusing mode. lol I suppose I could switch to AI Servo mode, but then I'd constantly have to switch AF points since I would no longer be able to focus and recompose.

 

[MTVision]

Not everyone has to use it. It's an option.
Here is a link to a great article that explains all the benefits including focus/recompose.

http://www.learn.usa.canon.com/resources/articles/2011/backbutton_af_article.shtml

 

[Neiby]

Not everyone has to use it. It's an option.
Here is a link to a great article that explains all the benefits including focus/recompose.

Canon DLC: Article: Back-Button Auto Focus Explained

Aha! I totally get it now, and now I can't wait to start trying it. Now that I see the problems it solves, I can see how incredibly useful it can be.