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I recently made the decision to move almost exclusively over to all Nikon FX bodies. For those not familiar, FX is the designation Nikon makes between their so called Full Frame sensors and their DX 1.5X cropped APS sensors. My main reason for switching from the DX sensor cameras, the D300 and D7000 bodies I’ve used for the past 5-6 years, is due to the tremendous low light capabilities Nikon’s FX cameras offer. But that’s a different story.
In this post I want to cover my experience with an equally important feature I rely on heavily – Predictive Focus Tracking. I specify Predictive Focus Tracking since virtually any camera made today produces quality autofocus images of subjects not moving. But when it comes to action, not all cameras are created equal, and that’s where Predictive Focus Tracking comes in.
Annie on a dead run for the tennis ball.
The three cameras I’m currently using and the ones tested for Predictive Focus Tracking were the D600, D800 and Nikon’s top of the line D4. I’ve seen many AF tests offered on other sites but I’ve never seen the tests performed using the techniques I use. My real world approach is easy for photographers to try themselves and more applicable to nature and action-oriented shooters.
So what is my technique? It’s pretty simple. First I recruit a fast dog, preferably a younger lab or retriever. I’m only interested in the ones that will offer to escort their ball throwing master and I request they bring their favorite fetching toy, which is usually a tennis ball. That’s it. The key to getting the best results is lining the pooch up AND getting the master to throw the ball in a straight line. I find getting the dog lined up is the easier of the two requirements. In fact, during this most recent test, my good friend Bill Buckley, world renowned hook and bullet shooter, was almost useless as a thrower. But his well trained golden lab Annie, persevered, didn’t leave until she was told and did her best to correct her crooked line while going after a poorly thrown ball. Annie and I held a meeting after the shoot and decided even though Bill was throwing like a girl we were able to pull off a sufficient test.
You’ll see in the images, I’ve included for review, Bill is off in the distance, about 30-40 yards. Annie sits by his side, Labrador enthusiasm pulsing through her veins as her master does a few circle swings warming his aging throwing arm. He eventually fires and Annie comes sprinting towards the camera. All jokes aside, the key to this test is to get your camera on the fast moving dog heading straight in to the viewfinder. This is where the camera either succeeds or fails. I shoot as many frames as possible on each throw, doing my best to keep the center focus sensor on the dog’s head or chest. With an animal moving at this speed it’s difficult to just keep them in your sights, so I don’t try for any composition other than to keep the AF sensor on the animal.
The camera was set to 9 Point Dynamic area-AF. Motor drive was set to Continues High and the AF sensor was set to the dead center, middle square. These are the settings that should give me the fastest Predictive Focus Tracking possible. Nikon has numerous AF-Area Mode settings. AF-Area Mode is selected via a little, mini lever on the front, lower left side of the lens flange. This little, mini-lever turns the AF from On to Manual. The inside, middle of that lever there is a button that you push to switch between AF options which appear on the top or rear LCD. Those AF options are:
These are all listed in the Nikon manuals and you can read what each one does there. For this test I used the 9 Point Dynamic-area AF. The concept behind 9 Point Dynamic Area-AF is to give you a small group of 9 AF points that start with one single AF Point but switch to the other AF Points depending on if the subject moves out of the single point originally chosen. This gives you a larger point to stay on the target.
Also, it should be noted that all images were shot at the 200-400mm’s maximum aperture which is F/4. Why is this important? By shooting at wide open or F/4 there is no benefit from a smaller aperture giving depth of field advantages to the image. All images have to be in focus without relying on depth of field from a smaller aperture.
Still charging towards the camera.
That’s all there is to producing this test. I’ve listed the results below which were based on me reviewing all of the photos from each camera in Apple’s Aperture. I would select the image and review it at 100% to look for critical sharpness. Sometimes the head may be slightly out of focus but the chest of the dog was in focus. If the sensor was shown to be on the chest then I considered the frame focussed properly. Remember, I wasn’t even trying to keep the dogs head in the upper third of the frame as you might normally do if she was just standing there. Annie was fast enough for me to just be happy to keep her in the viewfinder.
I’ve broken the results into three categories.
5 Stars = Critically Sharp, or as some would say, “wicked sharp” or “killer sharp”. I prefer Critically Sharp 
3 Stars = Just slightly out of focus. May even be focused enough to be usable for some people.
1 Star = Completely out of focus.
Unfortunately, the web does not provide the quality needed for reviewing these images as I get on my computer. That being the case, you’ll just have to trust my numbers. But believe me they are accurate. Let me know if you have any questions. I’m happy to hear your thoughts.
Predictive Focus Tracking Results, click on the links below to see results.
D4- 156 Total-Link
5 Runs to camera
1 Star-36
3 Star-11
5 Star-109
D800- Total 155- Link
6 Runs to Camera
1 Star-40
3 Star-13
5 Star- 102
D600- Total 93- Link
5-Runs to Camera
1 Star-28
3 Star-15
5 Star-50
As you can see by the numbers, the D4 did the very best which is to be expected since it’s by far the most expensive body. The D800 did better than I was expecting and the D600 did an admirable job being the least expensive camera of the group. From what I’ve seen in the past, these numbers are considerably better than I got with earlier Nikon‘s in Predictive AF. Even though there are a fair number of completely out of focus frames you have to keep in mind that there are few things we shoot that are as fast as a lab coming straight at the camera at that close of distance. Additionally, dogs run erratically which makes the test even more difficult. I’ve never tried it but my guess is these cameras would all have higher numbers of critically sharp images if you were shooting a race car at 200mph. Even though the car would be faster than a lab, the line it takes is consistent and the distance from the camera is further out. Overall a lab is a tough subject to nail down.
This entry was posted on Saturday, November 10th, 2012 at 11:00 pm and is filed under Equipment Reviews, News Worthy. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
Dan,
Very interesting article. I really studied the D4 images and you are right about not being able to tell much difference. I thought the “1″ images were pretty good and Kathy even agreed (I did not tell her what she was looking at – just asked if they were in focus).
I found your test interesting because Amsterdam was my first D4 shoot and I did exactly what you did with a lab playing fetch in a park running through water. I had the owner repeat several times so I could try out the high speed shutter – not the focus – and got some great shots.
Also the D4 and D800 did a great job in Kentucky getting the horse racing in focus. Nikon is making some killer cameras. I have no regrets about getting either of them and my son is thinking about the D600.
Take care and give Tanya a hug from us.
Fred
Hi Dan – love the real world test. I tend to agree with Fred that several of the images ranked “1″ even looked pretty good, but I know you said that might be tough to judge on the internet.
Dave and Fred, Interesting to hear your thoughts on the 1 Star images. Believe me when I say they are completely out of focus. Makes me realize what we can get away with on the internet. Thanks for stopping by and joining the discussion. Pass this on to your friends if you get a chance.
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Hi Dan, thanks for posting these results! I’m wondering if the number of critically sharp captures would have been improved if you increased to 21 (or even 51)points rather than 9. Any thoughts?
Cheers, D. Hamments
Dan, I heard David C keeps a couple robotic bald eagles up at his place in Alaska. The tourists, especially gullible photographers, love them!
Hey John Cote, I have worked at the Indianapolis Motor Speedway since 1987 as an observer and am stationed at the entrance to the pits out of turn four. Where do you shoot from? If I was not an observer, I would love to be a photographer there – especially now that I have a D4! That place gets in your blood doesn’t it?
David,
That’s a good question. Based on my past findings I’m confident the less number of AF Points is an advantage since the camera doesn’t have as many to search, theoretically making it quicker. However, seems I need to do Predictive AF Testing Round 2 at some point and give this a try. It would be interesting to see if it makes a difference.
Dan,
Good article and great real world comparison. I shot Indy Cars for part of my living and used both D4, D3 and D800 bodies this year. In my experience what really tests the predictive AF is objects coming pretty much right at you at speed. At a really fast track like the Indianapolis Motor Speedway shooting outside the through holes in the fence just above the safer barrier the Indy cars are coming at you at 220mph+. In this situation the D800 can’t cope very well. The D3 does a very good job and the D4 is superb. The interesting thing about this is at the same track when shooting NASCAR the cars are probably doing only 165-175 and the D800 can handle this much better. For both the D3 and the D4 NASCAR is easy. JohnCote
Dan,
Interesting test… 54% of the shots were 5 star with the D600, 66% with the D800, and 70% with the D4. On the other end of the spectrum, 23% of the shots were 1 star with the D4, followed by 26% with the D800, and 30% with the D600.
It goes to show what’s typically true… as you head up a product line, the marginal performance improvement from one model up to the next decreases the farther up the chain you move while cost starts to increase exponentially. Tests like this really help see where the sweet spot is in terms of the price/performance ratio.
With regards to how the 1 star images looked, It’s amazing what removing megapixels does to equalize the way images look. No doubt, I’m sure they look terrible at normal resolutions on your monitor. Showing a small segment of each image at 1:1 would definitely show the difference in sharpness. Thanks for sharing.
Hi,
Interesting test, but I wonder if you would have even better results by using the 3D-tracking? I thought it was made for situations like this, or not?
Good comment. However, I’ve used the 3D AF setting and for many things it doesn’t’ work all that well. Here’s why. The last time I shot this test I did try the 3D AF Tracking. I was shooting a golden lab similar to Anne, the one used in this test. The earlier test I’m referring to was run on grass with patches of yellow sand dispersed throughout and the sand was basically the same color as the dog. I found the 3D Tracking would sporadically grab a patch of sand due to it being the same color as the dog thus throwing the AF off. Where it might work, is in a situation such as a bald eagle against blue sky. If you can imagine, the contrast would be very distinct and I’m guessing the 3D may work much more effectively. I need to get out more and do more tests. Just need to find time and a bald eagle. Thanks for sharing your thoughts.
Very interesting. I have only shot the D4 once, but I own a D3s, D800, and D600. I shot a lot of sports.
When working in less than ideal light, the gap between these cameras is FAR more noticeable. For me, your predictive focus test only tells half the tale. At least for a lot of fast moving subjects,
What I have noticed is the time difference in time to get the initial focus lock between the bodies. The D600 takes far more time to lock than the other bodies, and the D3s (and presumably the D4) are nearly instantaneous. This shows up primarily in scenarios where you have to move from target to target and acquire focus in rapid succession. In basketball, volleyball, soccer, etc., it’s extremely noticeable.
In soccer and basketball, I am often dealing with the predictive AF capabilities of these cameras, however, my target is often slower, and often in dim lighting conditions. I’d be curious to see how your results change either shooting at daybreak or at dusk
BTW, I have found 3D tracking very effective in things where the subject is isolated against a fairly static background. Tennis, pole vault, high jump, etc.
Thanks for your test.
Aha, that certainly clarified why I couldn’t get a reliable focus of sea birds against a grey sky! I forgot that the 3D was color sensitive.
Living by the sea in western Norway, I am also chasing the eagles. I am patient, but so far I’ve only got a lot of fresh air. Thanks and take care.
Hi
Thanks for doing the test. The results are interesting. There is a lot more to consider other than what the others have already questioned… to know the best each camera could do. What about the speed of the predictive focus? Where was it set… normal? What if it was set faster/slower? And a big one… what if you were using an f/2.8 lens where the focus is better at the center focus point? Does it equal better predictive focus?
All good questions. AF was set to normal. You make some good points. Sounds like I’ll have to do think about doing another set of tests. So many things to consider. Thanks for sharing your thoughts.
Hi Dan.
Thanks so much for your most useful real-world test. I can’t imagine a better test for the predictive autofocus. I think there were an amazing number of properly focused shots, especially with the D4. I may have to replace my D3s.
JIM
Thanks for checking us out Jim. We appreciate your input.
Dan,
Your predictive autofocus test and results are very interesting as well as the comments made by the others.
Are you going to comment on other performance comparisons of the three bodies? I am considering the D800e as the successor to my D700.
Doug
Thanks for the information Dan,
I can’t remember a time that I last used auto focus in any camera. It isn’t an issue for me in getting action shots of animals, I usually use a Nikon-mount-adapted 560 mm Leica lens with a slide focus that I hand hold. It is very easy to track motion in any direction with that lens. For other scenes and lenses I always want to personally determine the primary focal distance for obtaining the depth of field I want in the scene at any given aperture opening.
Dan, thanks for the great read! I just bought D800 and haven’t tested it much, but what I find interesting is that I used to do lots of similar tests with my Sony A700/A900. Honestly, using Sony 70-400 I would consistently achieve more than 80% CRITICALLY SHARP focus in the exact same scenario.
Since I’ve sold my Sony cameras about two years ago, I’ve used Nikon D300, D300s, D7000 and D700 and none of them did better than the A700/A900 even paired with the Nikon 300/4 AF-S. When used with non-AF-S or Sigma SSM lenses the Sony cameras did much better than all the Nikons I’ve ever tested. Don’t get me wrong, I prefer Nikon now, but that’s one of the things I’ve always been amazed of…
Very interesting input. I really appreciate you sharing this. It would be fun to be able to test other systems. Maybe Sony reads this blog and will give me a shot at performing the same test on the newest Sony cameras at some point. I recently received the new Panasonic Lumix GH3 and Ill be testing this camera in the near future which will be every interesting since the GF3 has a completely different AF system. Stay tuned and thanks for adding your voice.
Hi Dan,
Great AF test! I also did a similar tests with my older D200 using my 4 year old son as a subject, but his running is a little more erratic. (LOL) I also recently switched to m4/3 for daily shooting but my G3 is very poor in this department. I’m thinking of upgrading to a G5 or a GH3 if it can focus as quickly and accurately, so am really looking forward to your next test.
If you have a chance, could you also test Olympus m 4/3, and see how they stack up in this department?
Mike, hope to get the AF test done sometime soon. In Patagonia right now but will be home in two weeks. Not sure I’ll be able to do the Olympus test but would like to know myself. Will see if I can come up with and Olympus system for us to run through the paces. By the way, the Panasonic is very fast AF it’s just the lag in the viewfinder that seems to mess things up. Otherwise the AF system is incredibly fast and accurate. If Panasonic could just solve this issue, images popping up in the EVF as we shoot, I honestly believe there would be no problems of speed with the AF.
I did a similar test using my then 15yr old son to determine that an old screwdrive AF 300/2.8 could keep up with him running at me, on the D3s, about as well as a 300/f4 AF-S, to my surprise. Don’t have a D4, but the D800 seems a little better in the AF department than the D3s.
Hi Dan,
Absolute fantastic story. We can read about hundreds of pages and comparisons of still camera picture reviews but this autofocus speed test is a great value to dicide a “fast” camera. With the autofocus unit from the D4 in the new D7100 I hope that the D7100 also follow my dog (And that cam is in my budget). With my existing D90, 80% of the pics are not 5 star sharp but mayby our dog is to fast. You’ll find some pics of our lovely borador/podenco on http://www.lootens.nl/f1/
Can anyone comment if the new firmware upgrade released by Nikon improved the results of these type of tests?
Fred, Haven’t had a chance to retest since the updates. Not sure if I will anytime soon. On the road in South America right now and will be for a few more weeks. Good question though and I hope to be able to sort it out. Thanks for adding your voice.
After the upgrade, my D600 feels a little faster in acquiring the initial focus + tracking the subject afterwards but that may be just my imagination. You did a good job in setting up a test that tells a real story, it’s way more accurate than anyone’s “feel.” Thanks for sharing the results