Struggling to keep Focus in AFC

[sk66]

This thread made me think about a few things.

I change my focus delay setting more often than I change my mode/# of points... it's that significant...

 

[coastalconn]

Good info. It was your thread I was trying to find earlier today! lol
I knew someone had mentioned that they still preferred the D300 AF.

Having used the D300s for sports... I still stand by my older comments saying the D7100 AF is better. But i hang out with a few people that think the opposite. I think in the end we'll find out its basically the same AF hardware with updated firmware

My backup lens is a 150-500 OS and one thing I know is legit is the center point working to F8 on the D7100. At 500 it is F6.3 and in really lowlight (like inside just playing around) The D300 would not lock onto a target that the D7100 would(in normal light it is fine). I think they are pretty much the same system with a little tweaking and they do perform slightly different for some reason. Also I was very use to the D300 just locking on to a bird in flight, it just didn't let go. Up until today when I changed the AF lock on setting, the D7100 would just loose focus for no reason. I'm not even talking about a complicated background either. A few days I had a Juvi eagle fly really close with nothing but blue sky behind it. I only had a few shots out of 15 that were of acceptable sharpness. Today I had a series of 15 that were all in focus... so for whatever that is worth....

Juvenile Bald Eagle 3 by krisinct- Thanks for 1 Million + views!, on Flickr

 

[SCraig]

Off late I have been trying to use AFC 9 point Dynamic for moving subjects like Birds, Kids & Moving vehicles with my Nikon D7000. Problem is that while I am tracking the Object with Back-button presses, my camera suddenly decides to focus on something in Background or Foreground and almost all my pics come out of Focus

Is there a way to Lock focus in AFC mode and then camera keeps it Locked

I have tried this with Tamron 70-300 vc & Tamron 17-50,

Something else to keep in mind is that regardless of the focus mode used, regardless of whether it is static or dynamic or single-point or continuous, no focus mode is going to help if the problem is not a focusing issue and in reality is motion blur. The subject can NOT move in relation to the sensor while the shutter is open or you will get motion blur. Many times this is mistaken for an out-of-focus condition but the two problems are not the same thing.

Motion blur is handled by using a faster shutter speed and/or panning with the subject so that it stays in the same place in relation to the sensor. The first frequently takes a lot of light or a wide aperture so you can use a fast shutter speed, the second takes a lot of practice. It is also easy to induce motion blur with poor panning technique which is why it takes practice.

 

[coastalconn]

An interesting observation today. I was shooting my D300 for the first time in months and I think the AF system smokes the D7100. I'm starting to think my D7100 may be a dud. On the subject of 9 pt AF dynamic, if you view pics in view nx2 the focus point does move from the center at least on my D300. So the camera doesn't just use info, it actually shifts focus points if it thinks your subject has moved from the selected point. Strange huh?

 

[MGRPhoto]

An interesting observation today. I was shooting my D300 for the first time in months and I think the AF system smokes the D7100. I'm starting to think my D7100 may be a dud. On the subject of 9 pt AF dynamic, if you view pics in view nx2 the focus point does move from the center at least on my D300. So the camera doesn't just use info, it actually shifts focus points if it thinks your subject has moved from the selected point. Strange huh?

Mine doesn't. I've tested this with D300, D300s, D700, D800, D3s and D4. The focus point only shows as the one I've selected. It will only move when using 3D.

 

[coastalconn]

An interesting observation today. I was shooting my D300 for the first time in months and I think the AF system smokes the D7100. I'm starting to think my D7100 may be a dud. On the subject of 9 pt AF dynamic, if you view pics in view nx2 the focus point does move from the center at least on my D300. So the camera doesn't just use info, it actually shifts focus points if it thinks your subject has moved from the selected point. Strange huh?

Mine doesn't. I've tested this with D300, D300s, D700, D800, D3s and D4. The focus point only shows as the one I've selected. It will only move when using 3D.

Pretty Bizarre, huh... here are 2 consecutive shots with focus point turned on..

 

[MGRPhoto]

It almost looks like it missed focus and went back to center. Were you selected on center? All I can say is that I've reviewed over 100,000 shots from my D300s while using Dynamic AF and not once have I seen that behavior. I've shot no where near as many shots with the other cameras I listed since they were either borrowed or rented but I never saw that behavior on those. Only when using 3D. And as the manuals state that is what should happen. Do you have a copy of CaptureNX2? I'm wondering if it shows the same. I'm typically using CaptureNX2 not ViewNX.

 

[coastalconn]

Yup center point af-c 9 pt dynamic. I process in LR5 so I don't have capturenx2. The focus point doesn't change in the viewfinder.. I went through some D7100 shots from today... I was shooting in 21 pt AF-C dynamic and for the most part it stays in the center, but I had an eagle in a tree pretty far away and the focus point moved 4 times according to viewnx2. I always thought the same thing you did that it used data from the surrounding points, not that it actually switched to them as needed.. I know it switches in 3d mode because it dances all over the screen.

 

[MGRPhoto]

I'll have to check ViewNX and see if it shows up differently.

 

[psran]

This thread made me think about a few things. I have self admittedly said I do not like the AF system in the D7100 as much as the D300. I had a revelation thanks to your arguments. I had the D7100 set on "Low" AF Lock on.. I checked my menu settings on the D300 and it was set to high. I went out with AF Lock set to high and 21 pt dynamic and Voila the D7100 tracked BIF just as well as the D300. So my thoughts are if you acquire a subject with your selected focus point the "dynamic" points read info and keep the subject in focus. I think the key to AF lock on is it say "abrupt changes in focus distance" my thought on this is the camera will keep the bird in focus even if it flies behind a tree. I will have to do more testing, but the D7100 performed much better for me this morning then it has in the past. With lock on set to low, I feel it was so sensitive it would detect the wings going up and when they went down the camera would instantly try to focus on what was behind it.. Hope that makes sense...

Today I thought of going through this thread again as my issue with BIF was still not sorted and this post above is a Goldmine out of whole of thread.

AF- on setting i.e. A3 in custom settings menu is as important as the AF mode that we use. I dug a bit into this setting and discovered that with A3 set to OFF, AF becomes too sensitive and keeps on seeking new subjects but if it's set to NORMAL or LONG, the camera will still track the Bird continuously but (this part is very important) it would keep the Focus locked even if a Bird flies behind a tree or passes a Busy background for 1 to 2 secs and wouldn't choose another subject during that duration.

Thanks a million Coastalconn for this post and I hope beginners like me find this post before giving up BIF

 

[sk66]

Mine doesn't. I've tested this with D300, D300s, D700, D800, D3s and D4. The focus point only shows as the one I've selected. It will only move when using 3D.

It moves, it just doesn't show it moving in the viewfinder except in 3D... it's in the manual...

 

[psran]

It moves, it just doesn't show it moving in the viewfinder except in 3D... it's in the manual...

Yes it does move and it shows in View NX2 but doesn't show in Viewfinder. Just makes me wonder, why the heck did Nikon make 3D tracking mode

 

[MGRPhoto]

It moves, it just doesn't show it moving in the viewfinder except in 3D... it's in the manual...

Yes it does move and it shows in View NX2 but doesn't show in Viewfinder. Just makes me wonder, why the heck did Nikon make 3D tracking mode

Eeeexactly. If the focus point were actually moving and different focus points were being used to obtain all the data necessary then there would be absolutely no difference between AF Dynamic and 3D tracking. I checked 20 or so files with ViewNX and CaptureNX2 where AF Dynamic was used and not one of them had the focus point anywhere but where I manually selected. I ran a few shots with 3D tracking and as expected the focus point is all over the viewfinder and the resulting image in both ViewNX and CaptureNX2.

 

[MGRPhoto]

Mine doesn't. I've tested this with D300, D300s, D700, D800, D3s and D4. The focus point only shows as the one I've selected. It will only move when using 3D.

It moves, it just doesn't show it moving in the viewfinder except in 3D... it's in the manual...

Actually in the manual (every manual) it says explicitly that it doesn't move. I've already posted several Nikon references backing this up.

 

[psran]

Actually in the manual (every manual) it says explicitly that it doesn't move. I've already posted several Nikon references backing this up.

I don't know what the manual says but it uses a different AF POINT when final pic is clicked