D-300 Continuous Focus?

[pete_harlan1]

<p>Has anyone been able to test and/or verify if the D-300/D3 or any camera for that matter, is continually focusing frame to frame at high FPS? It appears the answer is no.</p>

[bsd230]

<p>That is a good question. I would think at a high fps it wouldn't have time to refocus, but I could be wrong. I would be shocked if any camera could refocus during 5-8 fps. With a fast lens like 70-200 it might be possible.</p>

[rffffffff]

<p>In certain modes it uses predictive focusing, so in essence it is focusing inbetween frames at high fps even if it can't see the subject... I have many, many shots where the first or second isnt quite right but then it caught up and got a few, lost one, got another one, etc...</p>

[ShunCheung]

<p>Of course the likes of D3 and D300 attempts to refocus on every frame even at 8, 9 frames/sec, but that doesn't necessarily mean every frame is always correctly focused. The Multi-CAM 3500 does an excellent job, though.</p>

[bsd230]

<p>I would agree the Multi-CAM 3500 was a significant improvement over the Multi- CAM 1000 I had in my D200. Its ability to accurately focus even in low light and low contrast has to help in this situation as well.</p>

[pete_harlan1]

<p>I would love to see a study on this w/ various (Feet Per Second) parameters.<br>

Granted, given a specific and deep enough DOF, refocusing between frames is probably not an issue and unnecessary.</p>

<p>BUT, I'm very curious how it handles rapid excursions when the subject is changing distance rapidly, such a race car approaching at 500 feet, closing to 30 feet and then receeding back out to 500 feet.</p>

<p>Might make an interesting experiment.</p>

<p>Thanks for the replies.</p>

[elliot1]

<p>The camera's ability to focus successfully at 8/9fps is highly dependent on many variables including but not limited to available light, contrast of the subject, lens aperture, subject size, distance to subject as well as settings within the camera such as focus mode, number of focus points selected and probably significantly the focus lock feature.</p>

<p>I have been pleasantly surprised at the D3's ability to focus at 9fps - I take a lot of hockey shots and have noticed than often when a player passes in front of the subject I am shooting, the camera will in fact focus correctly on the foreground subject as it passes through the frame and and then refocus immediately on the background and get it right most of the time even at 9pfs. If I had the focus lock feature on with long delay for example, the camera would not focus on the foreground subject and one would erroneously conclude that the camera is not focusing 'fast enough' at its high frame rate. So the camera's settings play a very important role.</p>

<p> </p>

[rffffffff]

<p>a lot of sports photography is done with wide open apertures and long lenses, meaning not a lot of DOF. A lot depends on the amount of ambient light and the 'contrastiness' of the subject, but focusing between frames is absolutely necessary for a lot of sports. Race cars are kinda easy because they are contrasty and usually in good light, but figure skaters in dark rinks at f/2 are really hard to get good focus on. feet per second isn't really a big deal for the best cameras, but low light still is.</p>

[joseph_smith3]

<p>Good question. My study is not scientific. I just finished a wildlife photo contest where I took a lot of pictures of small birds using a 500mm AFS lens on a D 300 with battery pack some with a 1.4x tc and some without. All done at high C. Almost all of the images of the "same subject moment" had noticable differences in exposure, color, contrast. And some had differences in focus. ( I am not talking about the obvious out of focus ones.) Whether the focus differences were caused by the camera or the movement of the bird or a combination, I do not know.<br>

I quickly determined that I was better off using High C even for static portrait shots than low C or S. I got better results in terms of focus, contrast, color, etc. Usually it was the second or third frame out of the short burst. I ended up using High C for almost all of my shots during the contest.<br>

Joe Smith</p>

 

[eric_arnold]

<p>i've noticed that the faster the shutter speed, the more accurate high-speed focus tends to be on the D300. yesterday i shot an outdoor concert at 1/800-1/1600 sec and got a high rate of keepers.</p>

[williamchuttonjr]

<p>I shot a gymnastics meet with a D300. Continuous focus worked well at 4-5 fps. I was using a Nikkor 50/1.8 AF lens at f 2 or f 1.8 (no strobes allowed). Shutter speeds were 1/250 to 1/500. It wasn't perfect, but when the gymnasts were moving quickly (during dismounts and jumps) I could get focus on each frame of a 4-5 frame burst. In most cases the focus change was small (1-3 feet). I was surprised at how well the D300 focuses in continuous mode. The AF system rarely (if ever) focused on objects behing the gymnasts. I don't remember what the success rate was, but it was very good (at least my boss didn't complain and people bought prints).</p>

[chriscourt]

<p>On the D300, custom setting A1 (AF-C priority selection) allows you choose between focus priority, release priority or a compromise focus/release priority. If set to focus priority, the camera will reduce the frame rate to the point where it is able to obtain focus on every