Troubleshoot help, focus issues on d7000

Charmdesign

Hey can you guys help me troubleshoot? I have set my camera up to us the " back button focus". (AF On in the setting for the AF/AE button. I use AF-c single,point in the hopes I baby moves it follows her. I toggle until the focus point is over her eye. Then I hit the back button to "lock focus". Funny thing is, I never hear a beep to indicate focus is locked like I hear in auto mode. Even if I think I see the focus indicator showing focus. Also. If I move the camera or she moves, I don't see the focus point follow her, ever. If I switch to AF-a, 39 point, I get the same results. I am shooting with natural light here in the Midwest from a window. Using 1/250, f2, and a high ISO. Is something wrong?

I just started using this method but I will say I am not very smooth with it. I am finding it cumbersome to have to initiate focus with the back button, toggle and then go back to the back button. Perhaps this gets better with practice / muscle memory.

ben_dmb

From my experience with that camera you can hear the beep only on AF-S single point mode. Any other set up is going to mute the beep.

As for the tracking - you have to lock the focus first on you subject and then the camera will follow your subject. Many people here suggest to use AF-C 9 points.

Golf007sd

@Charmdesign: ben_dmb is correct. The "beep" only works when you use AF-S vs AF-C...which makes sense. If your subject is moving, given your setup, just keep holding down the AF/AE button and fire away. Remember, the PM I send you regarding "plane-of-focus" in order to get your subject in focus should you find her eye in positions you cannot focus on.

+1 also of AF-C 9

Charmdesign

If she or I move left or right, the focus point should "move" with where it locked? Like if I locked it on her eye? I have not seen it move and I don't know if I am expecting to much or my AF is broke.

Why is 9 point favored in this situation? From what in understand, there would be sensitivity to the area surrounding the main focus point.

PB_PM

When you use dynamic AF (point 9, 21, etc), the camera will try to lock back onto the subject with one of the other focus points. It will not highlight the active AF point, just the first one you started with.

Charmdesign

When you use dynamic AF (point 9, 21, etc), the camera will try to lock back onto the subject with one of the other focus points. It will not highlight the active AF point, just the first one you started with.

Okay, this is a breakthrough for me. I have been waiting to see the focus point change as my subject moves. So, al long as say, baby's head is in the 9 point area, I should be okay sounds like.

Charmdesign

When I review my focus point later after taking the shot, does this mean that focus should be in the general vicinity of the red focus point?

Right now I am faster manually focusing lol! I am almost used to using the back focusing technique.

Curious how focus and recompose technique works? I may have been inadvertently doing it already without knowing but would like to clarify how to do that technique. From what I gather you set you focus point toggling it into position. Then you compose the image, then shoot. Well the thing I don't understand is, when you compose, say you have now moved the camera. The focus point that appears when looking through the viewfinder isn't over baby's face anymore. Now, it's off to the side because you don't want baby in center if image. I feel like a few time I have tried this, that baby's face wasn't in focus after recomposing, rather the thing behind where it shows my focus point. Perhaps this is because I wasn't " locking" the focus. How do you so conventionally? Just curios what people did before this back button focusing technique.

I did read the manual but it was quite dry so appreciate your feedback!

Ironheart

Some folks like the AF-on technique, some don't. Me personally, I use the 1/2 press of the shutter button until I see the focus point flash, then I press all the way. There is a thread on AF-on, worth a read.
http://forum.nikonrumors.com/discussion/140/using-af-on-vs-trigger-button-for-auto-focus

Charmdesign

Thanks I will check that thread out.

Curious- if I have assigned my AF/AE button to function as 'AF-ON' and turned the shutter release button set to off. I have 9 point, AF-C setup. From what I understand, the only focus point that will be highlighted is the first one I set. BUT since I have 9 point setup, the surrounding focus points will ALSO be sensitive. My question is, how much movement can occur from me or my subject before I need to toggle to another point? Is it the case that if the subject moves closer or further the camera can keep focus locked relatively easily, but if the subject moves left or right, not so much.

I'm in spot where sometimes I will lock focus on her eye say, and baby will move a bit to the left or right or I will recompose and the focus point will now be left or right of her eye, sometimes even off her head. Assuming I'm holding the back focus button down, theoretically focus should be locked but I am curious what the limits of that are in 9 point, and want to know at what point would have toggle the focus point again?

Also- must I be holding down the button for focus to be locked or can I press it once and it will stay locked?

spraynpray

All this is covered by reading your manual. Are you really asking us to read it for you and explain what it means?

At close range I would only use single point and AFC for a moving subject then it is down to you to keep the focus point on the eye by moving the camera. Having the camera move the focus from point to point will result in it focusing on the wrong part of the subject sometimes when you want the closest eye sharp.

Charmdesign

All this is covered by reading your manual. Are you really asking us to read it for you and explain what it means?

At close range I would only use single point and AFC for a moving subject then it is down to you to keep the focus point on the eye by moving the camera. Having the camera move the focus from point to point will result in it focusing on the wrong part of the subject sometimes when you want the closest eye sharp.

No, I am not asking anyone to read the manual for me. I have read it, over and over and the language pertaining to AF is very dry. I find that I learn well hearing from others what their process is, in layman's terms. Or at least more casually and explanative then the manual. It may be the case I need to bounce my learning curve issues elsewhere. I just want someone to talk it out with as I go, and I don't have that locally or in person. I'm sorry if this thread doesn't "add" to the community.

I practiced today and I think I have a better grasp. To answer my question, you DON'T' need to hold the back focus button down, you can lock focus and remove your finger. It will stay focused like that until you change it again. This is like working in pseudo AF-S mode. If the subject isn't moving much this probably works.

However. If the subject does move....I discovered that if you do keep the button pressed, the camera will continuously be evaluating. And this was my point of confusion... I thought the AF was smart enough to " track " her eyes if baby moved a bit. Umm, no sir. You have to follow with the camera as you mentioned (or be mighty fast at toggling!?) So...I think I was confused initially thinking that holding down the button you could recompose a bit or baby could move a bit. Well, that is risky in my findings to count on the sensitivity surround the main point or assume the camera will follow. From what I understand, only in 3d mode will it follow/ move the focus point, and it is very inaccurate. When I tried to sort of recompose while holding the back focus button, sometimes the wrong thing ended up in focus.

What I learned today:
1. how to use pseudo AF-s mode - in AF-c, 9 point by pressing and releasing back focus button. I successfully locked focus on a still object and then recomposed.

I do wonder, do most people focus with the center point as I hear it is more accurate, then recompose? Or do they toggle a bit first?

2. If subject is moving, you better not only hold down the back focus button but also follow them like a hawk to keep the focus point over the desired focus area.

Is recomposing feasible with a moving subject? Say for making minor adjustments like adjusting composition on the fly so that the moving subject not be centered up.

Ran into a few snags though. Shot my daughters one year cake smash today. At a key moment of smiles, I found the camera lagging. I missed some of the best shots of the day. Incredibly frustrating to have missed those smiles. I was shooting in quick succession (but not in a burst mode ). Settings as described, AF-C 9 point. SRB set to release so very confused as to why this happened...??? Did the camera "choke" get bogged down? Should I have used another mode to capture continuous multiple shots?

ben_dmb

You need patience and practice and you will be able to figure it out by yourself. This forum is full of knowledge but we all must improve ourself by practicing alot and learning from our own experiences.

As for the AF lagging - maybe you need just a bit more light. Just a theory.

Charmdesign

I had natural window light...it wasn't too bad actually....I was able to use ISO 600, 1/250 and f3

spraynpray

Have you got your camera set to only release on focus? If you have it set to release the shutter when the button is pressed and you have a moving subject, you will get a shot, but it may not be sharp. Similarly, if you have the camera set so it can swap focus points when it decides, it may focus on the forehead or cheek, missing the vital eye. Hence why I said use single point.

Charmdesign

Right, I turned off release on focus so as not to have any potential for lag / missed moments. I filled take a lot of shots then whittle it down with these high action sequences. I am wondering if I should look into a burst mode. More practice and I now know that the reason I had some out of focus when I held the back focus button down was because I wasn't moving the camera to keep the focus point over baby's eye.

I can see how single point would take away the option for the camera to do something thinking on its own. This may have also been part of the problem (?) Maybe the camera made a bad choice. I will follow like a hawk and pan the camera more next time. I will have to experiment with single point vs 9 point. Anyone else want to weigh in on which of those is good for a subject such as a toddler?

PB_PM

Depends on how much the toddler is moving. I've been photographing my niece a fair bit since her birth in late May 2013, and found that the best practice is to be patient. Rather than snapping away constantly, I've learned to wait for those small pauses. Make sure you are using an adequate shutter speed (1/125s) and shoot. I generally use single point AF-C. I will likely have to use dynamic once she starts to crawl.

Charmdesign

In this instance, it was a cake smash session so lots of fast action from a crawler. First bite I cake all captured! First destroying of cake! Super cute.

Rx4Photo

Hi Charmdesign,

I tried to duplicate your issue with my D7000 and Nikkor 35mm f/1.8G lens and I'm not sure if I came up with the exact same "slow to focus" issue as much as it was a issue of simply not focusing accurately on what I wanted in focus. I think this is something that might be best remedied by you taking control of the camera instead of putting trust in the camera to grab what you wish for. As much as I like Back Button Focus it's still not what I'd use first in the case of trying to focus on moving kids.

I'd like for you to take a look at this YouTube video of a Sandy Puc photo session. (She's a highly respected and credentialed photographer). Take a close listen to the little "double-beeps" as she trains the lens on the child. She's continuously push/releasing, push/releasing, push/releasing that shutter button until she take's the shot that she wants. Not depending on the camera to follow the child's face or eye. It takes the decision away from the camera and places it in your hands.


That's actually how I approach nature photography as well. As advanced as these cameras are I still think that you have ultimate control over that decisive moment with which to grab the photo that you want.

Hope this helps.