Auto focus problems taking sports shots

[butlers]

I really am an aged newbie, so need to be treated gently please. I have tried to get through some of the threads on the forum but just get lost among the details. I'm more a "post photo" person and use Photoshop quite extensively for cropping, rotating, sharpening, etc., but taking the original shot is driving me crazy.
I used to have an old Kodak EziShare Z740 so just had to point and click to get a "reasonable" picture. I now have family playing higher-level rugby union and like to take pictures for distribution on club websites, facebook accounts etc.
My problem is getting the foreground subject (Player) in focus instead of the trees or crowd in the background. I understand this is a Depth of Field problem (dof ????) but don't know how to fix it. I seem to get a percentage of the pictures with exactly this problem.
I've tried reading the manual, and following various threads, but just get lost. Basically I have the camera in Sports Mode, with Continuous Shots. Everything else is in "auto".
I've included two of the shots with the players quite "large" in the picture, but the camera has focussed on the background. I reduced the sizes to 1000 wide as suggested.

 

[tirediron]

First of all, what camera and lens are you using? Generally speaking, there are two approaches to sports photography: One is to use single-servo AF (Nikon term, others have equivalent) and the centre focuing point, placing the focusing point on the subject and shooting. The other, (usually better) is to use continuous servo AF (ideally with back-button focus) and follow the action maintaining focus as you go. Read up on the focusing modes for your camera, and consider using shutter priority (1/500 sec min.).

 

[The_Traveler]

I understand this is a Depth of Field problem (dof ????) but don't know how to fix it.

Not exactly a depth of field problem.
With your old camera the focal length was relatively short and the depth of field at any lens opening (aperture) was greater.
So most things were in focus as long as the lens focused somewhere.

With the new camera, you are probably using a longer focal length lens (with a smaller depth of field) and you are not focusing on the player but the background. With a shorter lens it wouldn't matter but with the longer lens it does. So you need to learn to keep focus on the player.

Make the focusing point smaller, learn to pan with the player and use continuous focus.
Telling us what camera you are using and what model will simplify making more specific responses.

 

[butlers]

First of all, what camera and lens are you using? Generally speaking, there are two approaches to sports photography: One is to use single-servo AF (Nikon term, others have equivalent) and the centre focuing point, placing the focusing point on the subject and shooting. The other, (usually better) is to use continuous servo AF (ideally with back-button focus) and follow the action maintaining focus as you go. Read up on the focusing modes for your camera, and consider using shutter priority (1/500 sec min.).

Thanks TiredIron (sounds a bit like my golf stroke). I put all my camera details in my profile and thought they would just automatically pop up against my thread, sorry about that.

Camera Nikon D5100
Lens Nikon DX - AF-s Nikkor 55-300mm 1:4.5-5.6G ED

I have the lens set to A, and the VR to On.

I have been using Auto servo AF AF-A as the manual says AF-S is only for stationary objects. Also I have the Mode set to sport, so can't select anything but AF-A in Sports Mode. Unfortunately, I also can't do anything with shutter priority when set in Sports Mode (perhaps I shouldn't be using Sports Mode at all ???????)
I'm using Dynamic Area AF as the manual suggests this for moving objects.

I wouldn't have a clue what back-button focus is . . .

Thanks for your help, I guess I'll just have to keep experimenting.

Warren

 

[butlers]

I understand this is a Depth of Field problem (dof ????) but don't know how to fix it.

With the new camera, you are probably using a longer focal length lens (with a smaller depth of field) and you are not focusing on the player but the background.

Make the focusing point smaller, learn to pan with the player and use continuous focus.
Telling us what camera you are using and what model will simplify making more specific responses.

Thanks Traveler - as I mentioned in my reply to TiredIron, I thought the camera details would be automatically uploaded from my profile. I replied to him with all my camera details.

I am going to try single-point focus as I have the players in the middle of the Focussing Area but for some reason (in some photos) the camera decides it likes the background better???

I am panning across the action as best I can, but I must need more practice. This is another picture from the game and it appears to have ignored focussing on the background - perhaps this means I am not panning correctly, as the players are moving a bit slower???

 

[Kolia]

Keep in mind that the camera will attempt to figure out what is the actual subject your are shooting. In some cases, it will recognize the players in the foreground and focus on them. Other time it thinks you're trying to get at the guys on the side line.

Using a single focus point aimed at a player like TiredIron suggested will limit how many objects are potential target and it should focus more reliably.

I'm not familiar with de D5100, but usually in continuous AF the camera will anticipate the direction and speed of the subjects movement in order to keep it in focus when the shutter opens a fraction of a second after you've actually pushed the button. So if you are zoomed in really close and the player changes direction at the bad time, you might still miss him a bit. Be aware of that when figuring out what setting to adjust. You might have had it perfectly setup.

 

[lennon33x]

Did you ever consider back-button focusing? Not entirely sure how to set it (or if it's possible on a Nikon). It allows you to essentially pick the subject and fire as many shots as necessary provided the subject distance from the lens doesn't change. With a pretty significant DoF, you should be able to click away. I use it when my girls are on swing sets, constantly changing. I can adjust it to wear it's focused at a distance, not necessarily on a subject and click when they're in focus, not when the camera tells me they are (i.e. Canon EF 50mm 1.8 is REALLY slow, but DoF is great). It allows me to choose the sharpness of the picture and not allowing the camera to do it. IMO, I prefer back-button focusing because it keeps ME in control, not the lens or the camera.

 

[SCraig]

... I'm using Dynamic Area AF as the manual suggests this for moving objects.

The manual was written by Nikon who are certainly going to try and justify the "Features" that they put in the camera's firmware. In my personal opinion any form of dynamic area autofocus is something that should be confined to the bit bucket and the firmware space used for something useful. I've tried to use Dynamic Area AF several times and have NEVER, not one single time, EVER had it do what I wanted it to do.

I shoot birds, wildlife, motorsports, anything that moves. My camera is ALWAYS set to single-point continuous (AF-C) autofocus. I don't want the camera deciding where to focus, I'll tell it where to focus. I don't use back-button focus and have never seen a need to press two buttons when one will do the same job. I shoot in bursts of frames. It costs no more to shoot 500 frames than it does 50 frames. I'll worry about which are the best when I get home and have time to look at them.

Learn to use your camera without reliance on "Scene" modes. They enable and disable things that you are better off controlling yourself. Learn to use shutter priority, aperture priority, and manual mode. Learn to use the "Hyperfocal Distance" along with depth of field since it allows you to worry less about where the focus point is.

 

[Goldcoin79]

Hi butlers

Just thought I would add to the discussion as I have the same camera as you and have got some good shots when I've used it for taking pictures of birds of pray.

I set my camera to shutter speed priority mode and set it to 1000th sec, set the ISO to a value that allows the aperture to set itself to a wide aperture (so I get a shallow depth of field) . I then set my focus to continuous AF with the focus point set in the middle and I also set it to dynamic focus mode. I then start with my subject in the middle of the frame so the focus point is on the subject, I then follow the subject with my finger half pressed on the shutter then fully press the shutter button and take bursts of shots with continuous shooting mode.

I have even found you can recompose why you are shooting and it still keeps you subject in focus.

Hope this helps, this is just my experience but one thing I have learnt in photography is that people have different ways they like to do things (there's no right or wrong way)

James