Auto focus D300s

[ccommins]

I see so many post about how great D300s and the auto focus is outstanding. When I use my 35mm lens the auto focus

works good. When I use my 70-300mm AF is horrible, the pictures are all blurred, but I have tried this lens on my D80 auto

focus and the pictures are good. I prefer to use manual on both cameras but there are times when auto focus come in

handy. Am I doing something wrong, any suggestions?

[Jerry_]

<p>Which 'model' of the 70-300mm AF lens are you using? If it is not the AF-S 70-300mm VR Nikkor lens, then you may need a tripod or monopod for shooting at 200mm or more. </p>

<p>And you may need to check your instruction booklet for what settings you have made for the AF controls....</p>

<p> </p>

[Matt Laur]

<p>Are you seeing blur from being out of focus, or motion blur from using a too-slow shutter speed? If you can post an example of the problem using a file that has the EXIF data intact, you'll get some better feedback on what's going on.</p>

[Sanford]

<p>It's very easy to dislodge the AF switch on the D300 (I don't know if the D300S is the same). I find I have to check it constantly to be sure I haven't accidentally moved it to continuous or manual focus.</p>

[ShunCheung]

<p>The D300 and D300S use the same AF system and have the same AF controls. The AF mode control (S/C/M) switch is just below the lens release button on the front of the camera. I have pointed this out before: If you hand hold your camera correctly by using your left palm to support the bottom of the camera and lens, there is almost no way you can accidentally flip that switch because none of your fingers should be anywhere close to it. It can be a problem if you use your left hand to hold the left side of the camera; that is an unstable way to hold an SLR.</p>

<p>Back to the OP's question: Nikon's Multi-CAM 3500 AF system used on the D3, D700 and D300 is complex. Most likely you are doing something wrong. The AF mode (C/S/M) setting discussed above is one issue; the AF area mode set on the back is another one. Additionally, the Custom Settings A1 and A2 freqeutnly lead to problems. To get started, make sure your A1 and A2 are both set to focus priority instead of release priority.</p>

[ccommins]

This is example of the problem

[ShunCheung]

<p>Carol, unfortunately, it is very obvious that even as a small JPEG file, your image is unsharp. That means it is really unsharp.</p>

<p>As I said earlier, the Multi-CAM 3500 is a complex auto focus system. If you are willing to spend some money and time to study it, Thom Hogan has done a very thorough job with his guidebook: <a href="http://www.bythom.com/nikond300guide.htm">http://www.bythom.com/nikond300guide.htm</a><br>

However, Hogan provides a lot of technical details and it takes a long time to read. Whether you need so much details is up to you to decide. My full disclosure is that I was one of the proofreaders for Hogan's original D300 eBook 2 years ago, but I was strictly a volunteer and was not paid at all. Hogan and I merely exchanged e-mail and I have never even spoken with him over the phone.</p>

<p>As it turned out, during that proofreading period, I suddenly needed a small surgery and had to stay home for a week afterwards. So I had plenty of time to read it. Still, that is a lot of reading and is not always exciting. </p>

<p>Other than Hogan, there are a number of D300S guide books that I have seen in bookstores, but I don't have much experience with them.</p>

[Sanford]

<p>Shun - I happen to use my left eye and alway have and always will shoot verticals with the right side of the camera down. This gives me the best support because I can lock by right elbow against my body. If the AF switch is moved inadvertently by me this is a 100% design flaw in the D300 for making the switch sooooo easy to move. Doesn't happen with the D50 or D80, just the D300. I have learned to constantly check and recheck the switch to make sure it is in the right position and I have largely eliminated the problem. This is the "correct" way, for me, to use a camera. I will not relearn 40 year old habits because Nikon screwed up.</p>

 

[ShunCheung]

<p>Sanford, the D300/D300S has an optional vertical grip and the correct orientation for vertical should be right side up; that is the same for bodies with the grip built in such as the D3 and D2 families. If you choose to use the camera differently, that is your choice. I think it is a little unfair to blame it on Nikon.</p>

[kohanmike]

<p>I looked at the EXIF details and that image sure looks like motion blur to me, meaning at 1/20 shutter speed used, you cannot hold the camera steady enough. I have the 70-300 VR and find the vibration control to do an excellent job at low shutter speeds. If your lens is not the VR version, you just can't hold steady enough at 1/20. On a D300 you can set the ISO very high to get more shutter speed, like 1600 rather than the 200 where it was set.</p>

[eric_arnold]

<p>carol, i have a d80 and a d300 and the 70-300 ED, which is an older design with screw-drive focus. the d80 most certainly does not have better AF than the d300/s, but it does have a more idiot-proof AF mode selector.</p>

<p>as others have pointed out, using AF-C instead of AF-S on the d300 is the most like likely culprit, because in essence you are telling the camera to shoot before focus is locked. this is somewhat of a design flaw on the d300, however, i am used to it by now.</p>

<p>another probable possibility is that you did not use a fast enough shutter at long focal length. with the 70-300 ED, there is a great deal of camera shake past 200mm. using that lens handheld requires a shutter of at least 1/(focal length) for still subjects. for moving subjects 1/(2x focal length) might be needed to avoid "the blurs."</p>

<p>aperture could also play a role in sharpness. if you were shooting with the 70-300 wide open at a long focal length, say 250mm, then you would be at 5.6. with the 35/2 or 35/1.8, the same aperture will be stopped down several clicks = much improved sharpness. in my experience, the 70-300 is somewhat bland wide open, but perks up and becomes really contrasty and much sharper at f/8. for best results with this lens, i would avoid shooting wide open if you can help it. again, this will require either a fast shutter or a tripod at longer focal lengths with both the G and ED models; with the VR model, you can get away with a slower shutter.</p>

<p>finally, a somewhat remote, possibility is that you were too close to your subject and the camera couldn't focus correctly. this can happen when using a telephoto lens in a situation where you need a macro lens, or a lens with better minimum focusing distance.</p>

<p>my advice is to troubleshoot, read the manual if you have to, and use the process of elimination to isolate the problem. chances are, it's not the camera nor the lens, but a technical issue which requires a better understanding of how to properly set the controls to make your gear do what you want it to do. practice really does make perfect.</p>

<p> </p><div></div>

[johnw63]

<p>I understand the D300 has a lot more AF points to choose from. Perhaps the wrong was was selected ?</p>

<p> </p>

[Matt Laur]

<p>Right - the shot was at 300mm, and 1/20th of a second. In focus or not, that's just asking for motion blur. And even if the camera is rock steady on a tripod, the butterfly itself, and the plant it's on are <em>very</em> likely to move a bit during that long exposure. Just raise the ISO to make the camera more sensitive, and thus get a faster shutter speed. The camera was set to [P]rogram auto mode, which means that it was basically in point-and-shoot mode. The best way to take control over what happens is to ... take control. Don't let the camera guess about what's most important, <em>tell</em> it what's most important (in this case, a faster shutter speed).</p>

[ShunCheung]

<p>Thanks a lot Michael Kohan; I totally missed that the sample image was captured with a 300mm lens @ 1/20 second on a body that has a 1.5x crop factor. As Matt says, even on a sturdy tripod, 1/20 second is going to be problematic. Even a slight bleeze will cause a lot of vibration on the flower and therefore the butterfly at such a slower shutter speed.</p>

[johnw63]

<p>I thought the poster was implying that as a general rule, they got better results with the previous camera, and THIS was just an example shot. If all other variables are the same, like lens, and shooting style and metering mode and program mode, then the only thing that would change is how the camera focuses.</p>

<p> </p>

[ccommins]

After reading all the post I took my camera, the manual and took expermental pictures. They did get much better. I find the weight of the camera is also a problem, I have small hands, the D80 is a much better fit. I will be using a tripod with this lens it is 70-300mm AF is not a VR. Changing the settings worked, but I prefer to use manual. Most of all I think my attitude has to change toward this camera, it intimidates me. People tend to think when you have a camera like this you can work miracles. Not so! Its only as good as the person pushing the shutter. The camera was a gift from my husband, I don't think I would have purchased it for myself. I have it now, so I have to get use to it.

[aladennis]

<p>Sanford, <br>

Take a piece of Gaffer tape and place it over the offending button or switch. Works fairly well for me to avert unwanted changes.</p>

[aladennis]

<p>Sanford, <br>

Take a piece of Gaffer tape and place it over the offending button or switch. Works fairly well for me to avert unwanted changes.</p>

[walterh]

<blockquote>

<p>People tend to think when you have a camera like this you can work miracles. Not so! Its only as good as the person pushing the shutter. The camera was a gift from my husband, I don't think I would have purchased it for myself. I have it now, so I have to get use to it.</p>

</blockquote>

<p>Carol you learned a lot in a short time :-) Perhaps more than many people ever will. So in short you are on track and will master your camera soon. Go to amazon and get a book on basics of digital photography and you will be set soon. It is a challenge but it is fun as well and the learning is fast because you see the results immediately. Have fun.</p>

[ShunCheung]

<p>Carol: This is something to consider: <a href="00MWYs">http://www.photo.net/nikon-camera-forum/00MWYs</a><br />As I added in that thread, it looks like there is now an updated version of that DVD with discussion on video capture, which did not exist when the first version came out back in 2007. (The D90 introduced in August 2008 is the first Nikon DSLR with video capability.) While I have the original version of the DVD, I have never seen the new version.</p>

<p>BTW, some 30+ years ago, I read in a Chinese photo magazine about an alternative way to hold your SLR vertically. You can hold it with the right side down so that the regular shutter release button is at the bottom. You use your right plam to support the camera from below and use your right thumb to press the shutter release. Your left palm should be supporting the lens from below. Back then, I did that for a couple of years and I thought it worked quite well for me. Today, if your camera has a vertical grip, of course this method does not make much sense. Otherwise, it is something to consider.</p>