D7000's AF

[cyrus_procter]

<p>I own a D7000, I like to shoot sports, nothing professionally just for fun, specially basketball. At the moment I'm using my D7000 with a 70-200 VRII. I'm quite happy with the image quality generally shoot at ISO 3200, 1/500th & F/2.8. My beef is with AF system. I use the full 39 point AF, Continuous mode, 3D tracking focus, priority release. Here's my issue, my D7000 has a tendency to miss shots, and not just in motion extreme shots, but even still shots. Matter of fact with my 85mm F/1.4 it has a tendency to miss shots in low light. Matter of fact in general its very miss prone in low light. I'm not talking about super low light, or sometimes even low light, especially flat light and sometimes normal light. I realize that all cameras are weak in low light, or at least the majority of cameras, but its very frustrating to me when I'm outside, the sun is setting, but I'm still getting 1/750, ISO 100 & F/2 and that's correct metered exposure and the damn system can't focus to save its life. Yes Yes I'm very aware of the AF fine tune, heres the thing, in contrasty light its just fine, hits every time, but for some reason in lower light it tends to just miss all together and way off, like several feet. A lot of times if I put it to -10 in low light it preforms much better, but if I leave it there its off in bright light. Does anyone else experience these issues? I had several D3s's and some serious glass (400 F/2.8 VR, 200mm F/2 VR, 135mm F/2 DC to name a few) on loan for several months. I'm very familiar with paper thin depth of field and fast glass and AF systems. When I say its "off" I don't mean I got a nose but missed the eyes, or got ears and missed the eyes, I mean that I got a branch 3 feet behind the model :(. Or in sports I'll lock on a player standing still and get a player 4 or 5 feet behind him. I've never really compared the AF systems on D7000 & the D3s (which I no longer have access to) in low light. I love the D7000, but if anyone has a D300 or D300s have they compared the AF system to the D7000 in low light? I'm thinking for me this maybe a better option.</p>

<p>For the record my camera was serviced by Nikon several months ago, where it was given a clean bill of health.</p>

<p>Don't get me wrong, I get good shots, I work around AF systems. I just feel like I'm getting more misses than is reasonable given the lighting conditions. (I've had the D3s out at ISO12,800 F/1.4 & 1/50 of a second, and it was probably 2 stops under exposed. Now that's a more than reasonable place for an AF system to have issues IMHO, not ISO 100 F/2 & 1/750 which was correct exposure) I'm wondering if I'm alone or if there are more people that feel the same.</p>

[marypar4]

<p>take it off three d and go to afc 9 points three d is not reliable</p>

[robert_hooper1]

<p>I've had similar issues with my D7000 in low light situations. My impression is that the electronics of the D7000 are just not up to the sophisticated auto focus modes. It's a consumer camera after all. My suggestion to you would be to upgrade to a prosumer body with a bigger brain.</p>

[Wouter Willemse]

<p>On my D300, there is a noticeable difference in continuous AF using all 51-points 3D tracking, or calming it down to 21 points or 9 points only. The latter is clearly faster and more reliable. I cannot compare directly to a D7000, but I have the settings banks of my D300 set for rather different AF settings - one for moving objects/sports, optimised for contiuous AF and tracking; the other setting for normal situations.<br>

So, what Mary suggested. The default settings of the AF systems aren't ideal for continuous AF, if you want to get the best out of this camera, like any camera, you need to spend some time finding your best settings. Given that it seems you only tried its defaults, I would not yet blame the D7000 here, but rather accept you have to experiment a bit more to hit your prefered settings.</p>

[georg_s1]

<p>double posting - sorry</p>

[georg_s1]

<p>Skyler, <br>

I've tried several AF-methods with the D7000 for indoor-sports and use most of the time 39point-3D-tracking. Sometimes (color and style of the players shirts have a huge impact on focus-accuracy) 9points work better. Testing for the best settings from game-to-game isn't nice, but the results are worth it.<br>

I've missed focus on sports-shots with all of my Nikon bodies - even by manual focusing a 300/2.8 on my FM2 :-)<br>

Cheers, Georg!</p>

<div></div>

[elliot1]

<p><em>"</em><em> I use the full 39 point AF"</em> This is probably why you are having problems. Use a single point, (one of the cross type points) and your issues will likely disappear. </p>

[rodeo_joe1]

<p>I think it's important to realise that a camera cannot read your mind! That's a facile and obvious thing to say I know, but why would anyone expect a camera to pick the exact same focus spot out of 39 that the photographer is thinking of? That's basically the same as leaving your focus to a random 1 in 39 chance.... or even worse when cameras have 51 or more focus points on offer.</p>

<p>Almost the very first thing I did with my D700 was to change the focusing area to a single point. That was after watching a frantic display of little red focusing rectangles buzzing about over most of the screen for a few minutes. Fascinating and distracting in equal measure, but entirely useless for focusing.</p>

<p>So, like everyone else has suggested, +1 to cutting down the number of focus points that your camera can choose from.</p>

<p> </p>

[cyrus_procter]

<p>Thank you all for the input! Its been very interesting hearing the different perspectives. I'm sorry, I forgot to mention that I had tried several other types of AF, including C 9-point & C 3D 11-point instead of the full 39 point (those are the only two options on the D7000). I fully realize that more than 9 points of AF is something new in this millennium, that when AF first dawned Sports photographers got awesome-in-focus-shots with 1 AF point in the very center of their camera. I'm not shooting for a magazine or anything, the purpose of my shoot is to get "the moment" and usually those moments aren't something simple like a jump up to shoot, its more like the ball carrier whips around a defender; Single point AF tends to be very limiting in these situations (frankly any kind of AF does, but the 3D will tend to get keep up better than I can, sometimes). Although I will say 9 point worked decent and I think I'll try to give that a shot again. I've used 51-point 3D tracking with the D3s and the 400mm F/2.8 & 200mm F/2.0 shooting things like motocross. For me, the D3s's 51-point AF worked very well, of course that's on Nikon's top-of-the-line sports camera with top-of-the-line sports lenses, its obvious the D7000 doesn't have the same processing power \ AF node sensitivity that he D3s does, and not that I expected it too, or maybe I did expect it to, more than I realized :). It is acceptable I guess, if you are shooting kids walking around in perfect light (probably what it was designed for), not fast moving sports players in low light gynaziums. What I'm most frustrated with are shots of guys not moving so quickly that still miss, even when I do shoot single point. Or when I'm shooting models outside and every single time it focuses 2 or 3 feet behind the subject in single point. Maybe its those situations that make me credit more misses in sports to the AF than it deserves.</p>

[kwasi_a]

<p>39 point 3D is nice on the D7000, but it isn't on the level of the D3. It doesn't hold colour information as reliably so won't always track your subject the entire time. Setting the focus lock on to 3 seems to help somewhat. The 3D tracking is <em>very</em> dependent on colour discrimination for accuracy. For a bird against a blue sky it's fine, but if you're shooting team sports where there are multiple elements in frame with similar (well, near identical) colour, it's not going to do as well. <br>

For that environment 9 or 21 point Dynamic AF is much better IME. There is still some leeway with framing (with Focus lock on according to how likely the subject is to move off the selected focus point or be obstructed) and it tends to be far more accurate in subject selection in lower contrast light.</p>

[daniel_bliss]

<p>I strongly recommend setting up the banks (U1 and U2 on the dial) with different focus adjustments for different color temperatures. For 3000K light I'd suggest you start with -12 or so for f2.8 zooms and primes, -8 for f3.5 and -5 or -6 for f4.5 lenses. For daylight it isn't a problem but the D7000's AF responds differently to warmer reflected light on the subject (i.e. cooler color temperatures on a Kelvin scale). Once you have an appropriate setting for the light on the subject it should work OK. All my lenses are spot-on for backfocus/frontfocus; both my D7000 bodies behave perfectly in daylight but veer toward backfocus in exactly the same way under most indoor lighting, unless you're fortunate enough to be working under daylight-balanced indoor light. You'll notice that focus adjustment goes up and up with a wider maximum aperture; I would suspect that you may have difficulty being able to adjust an f1.4 lens on the D7000 under incandescent as you'd be butting up the maximum adjustment of -20 if my experience is anything to go by.</p>

[niko_korhonen]

<p>See DPReview:<br>

http://www.dpreview.com/reviews/nikond7000/page11.asp</p>

<p>During their testing they specifically mention some AF issues, especially in low light, low contrast situations. They also point out that the 39 focus points are not cross hairs...something I did not realize until I read the article.</p>

 

[jeff_denyer]

<p>Kwasi is right on, 3D is great for a single subject like a bird or person moving in an unpredictable way, it is using color information to lock on and can even make predictions of where the subject will be by tracking speed and direction. But when you have multiple subjects moving around with the same colors you can see how the camera can get confused. Try this, use single point or 9 point focus, with AF-C, and change setting a3 in the menu to off, this will eliminate the delay for the focus to lock on and allow the AF-C to focus right away.</p>