What are we doing wrong with this lens?

Well, if the AF is on, it seems that you have an unique Tamron-Lensbaby which may worth a fortune someday. You should contact Tamron because this lens need internal elements (or bayonet) realignement. Good luck !

 

 

Thanks R.K. for expanding my theory(supposition).

<p>[[common practice states twice the focal lenth for minimum shutter speed (310mm = 620 sec min shutter speed for still subjects)]]</p>

<p>I have never heard anyone say this. Common practice is shutter speed ~= field of view.</p>

<p>I am not sure there is anything is wrong with this lens. One cannot tell very well from these images. Especially without the exif information being supplied for focus protocol, etc. Was it single servo, continuous, predictive, etc.?</p>

<p>The wide aperture, especially wide open, on a telephoto will give a very narrow depth of focus. Often we <em>want</em> that to isolate a portion of the image.</p>

<p>1st picture is of a subject and environment where nearly <strong><em>any</em> </strong> camera's autofocus would be challenged. Where is it supposed to choose to put the focus, the grass in foreground, the wire, the fence, the cow's body or the cow's head? I have a D70s, and one of the things that interferes with autofocus from time to time is the large size of the five focus areas available. If there are more than one object within the focus area selected by the photographer (BTW, which focus protocol was being used?), then the autofocus has to choose between portions of the image within the autofocus area. What it will do on some occasions is just split the difference with the result that nothing is in focus. Image one is definitely a manual focus subject. For more than the cow's face (and maybe more than one of them), stopping down the aperture is called for to increase depth of field.</p>

<p>The 2nd image, the running dog, on a curved field of grass, is something again that this camera (or any camera) may not be able to cope with either. At least not in the mode selected. The dog is a moving target. The curved grass field offers iteself as a focusing target as well. Predictive focus might have been able to predict the focus change on the moving dog between the time the shutter control was first pressed and focus measued and the lag time when the shutter actually operated. Single servo would likely be off, and not the best choice. Predictive is good, but not perfect. And, again, the autofocus areas on the D70 are large. (One of the reasons I upgraded after a couple of years even though the camera can make stunning images.) So, how much of this <em>distant</em> dog filled the focus area selected and how much of it was some portion of the grass? Another issue is the focusing speed of this lens? Is it screwdriver or does it have an internal focusing motor as a corollary to Nikon's AFS or Sigma HSM? I am not that familiar with Tamron's alphabet soup lens specs. If screwdrive, or even AFS imitator, the dog could have moved between focus measurement and shutter activation. Screwdrive lens are not noted for fast autofocus nor for the ability to follow a moving subject.</p>

<p>I would not send the lens back until it is tested on targets within the camera's ability to automatically focus, with subjects that <em>fill</em> the focus area, and with the focus protocol that is appropriate to the subject, e.g., single servo, continuous, predictive, etc.</p>

<p>Let us know, and perhaps supply full data. Just my $.02.</p>

"Thanks L.K. ( not R.K.)" Sorry Landrum Kelly , just a typo...

<p>BTW, my apologies if exif data are available in the images. I am not at my computer with editing software that can read the exif, and so must deal with the visible image and my knowledge of the operation of the D70/70s. Focus mode could very well be an issue here.</p>

 

<p>"If there are more than one object within the focus area selected by the photographer (BTW, which focus protocol was being used?), then the autofocus has to choose between portions of the image within the autofocus area. What it will do on some occasions is just split the difference with the result that nothing is in focus. Image one is definitely a manual focus subject. For more than the cow's face (and maybe more than one of them), stopping down the aperture is called for to increase depth of field."</p>

<p>this occurred to me as well. it looks like the camera got confused by the wire and focused on the rope. also the DoF here is very shallow, which is why the cow is OoF.</p>

<p>"Another issue is the focusing speed of this lens? Is it screwdriver or does it have an internal focusing motor as a corollary to Nikon's AFS or Sigma HSM? I am not that familiar with Tamron's alphabet soup lens specs. If screwdrive, or even AFS imitator, the dog could have moved between focus measurement and shutter activation. Screwdrive lens are not noted for fast autofocus nor for the ability to follow a moving subject."</p>

<p>AFAIK, the tamron has a micromotor. DP review notes its AF is slow, so it would not be the best choice for action, especially on a D70, which doesnt have the fastest AF speed. that is not the fault of the lens or the camera per se, but rather a corollary of their limitations. for still life and portraits, that 70-200 is supposed to be pretty good.</p>

<p>i would second david's opinion to do further testing of this lens under more optimal conditions, before chucking it up as a lemon.</p>

<p>Could you guys provide specific examples of tests we could do? She's more than happy to take pictures and post them here for your opinion.</p>

<p>I think maybe you should do what the others have suggested, Mr.noneofyourbeeswax and do some test shots and post them or just take the dam thing back already!</p>

<p>"Could you guys provide specific examples of tests we could do?"</p>

<p>try a static subject (test charts, brick wall, fence post, flowers, stop signs) with a tripod in aperture-priority mode at apertures from f/2.8-f/16. stick to base ISO. if you can replicate your results above under controlled conditions, you may have an issue with the lens. otherwise, it's most likely UE (user error).</p>

<p>you may also want to bracket exposures with different AF and metering settings under varying conditions to see how that affects lens performance. in general, AF-S (single) results in better sharpness than AF-C (continuous), since the camera wont fire without a focus dot confirmation.</p>

<p>good luck!</p>

<p>I would say it's bad.<br>

In the first shot, the wire fence is nearly parallel to the plane of focus. It doesn't look like "zoom effect" to me, as it's not consistent enough, nor truly radial around the center. Look at the wooden post at left and the fence wire at both left and right, along with the parts of the cattle not at center. The "blur" appears to go lower left/upper right. The tree in the background appears to be blurred in a somewhat perpendicular direction. Also the weeds in the foreground are blurred more to the left side than the right. This is also seen in the second shot; sort of an off-center zoom effect.</p>

<p>subjects are moving, the dog for sure, so she might be zooming in (or out) and might have depressed the shutter while doing that. shutter finger too quick for the zooming to be settled.</p>

<p>Are you holding just the camera? You should be holding the camera body with one hand while the other hand supports the lense, especially with a longer lense. I notice a lot of people who hold a long lensed camera by holding only the body and no support on the lense, then they wonder why the image isn't sharp, even at 1/800 - 1/1000 it won't be fast enough to give a sharp image. Would you hold a rifle by only the stock and expect to hit the target?</p>

<p>Sorry, guys.. but there is no way this can be a motion blur or focus problem. Be cause the blur is not consistent within the frame. They seem to be ok in one spot, but the rest of the photo shows blurring which is impossible to produce with out of focus or blurred shots (even zooming). The lower part shows a kind of blur that MIGHT look like some zooming during shutter release.. But the movement is NOT radial, and the upper part has no signs of those "comas". The upper part might seem out of focus, but the distance is the same as the points which are in focus.<br>

And then.... misaligned elements. Have the lens replaced. Full stop.<br>

That is, unless you like this "creative" output: it's not bad for some kind of images! ;-)</p>

<blockquote>

<p><strong>Terry Foster</strong> : Kari i did not use auto mode i never do.</p>

</blockquote>

<p>I meant that OP's image was shot in aperture priority, not in auto as stated in his post.</p>

<p>You didn't mention how you can dublicate that kind of sharp center + uneven blur with a normal working lens. It's so bad it looks like home made tilt-lens.</p>

<p>The pictures are not merely blurred but distorted as one moves outward from the center.</p>

<p>This is a bad lens, period.</p>

<p>--Lannie</p>

<p>I'm not technical expert, but when I first looked at those images it looked like it could have been taken with a wide angle lens because of the distortion. But because it's clearly not a wide angle lens, something definitely isn't right. I have many shots using the 70-200 2.8 nikon lens for my equine gallery and none of them look like that. Have a look at my gallery if you like. I know it's a nikon lens and is most likely better optically but yours really shouldn't be THAT different.</p>

<p>http://www.photo.net/photodb/folder?folder_id=863401</p>

<p>I know I took some at 2.8, I'm just not sure how to pull up the exif data, or if those images at 2.8 are in my gallery... I did all mine hand held. Anyways you should really just send it to the manufacturers and have them give it a good tune up. Unfortunately I don't think you will have any luck taking it back to the store considering how long you have had it already. It's not the stores fault, it just happens from time to time with camera equipment. Every now and then someone will get one that isn't working exactly as it should and manufacturers expect that to happen. It should be covered under warranty and you'll get it back working flawlessly.</p>

<p>I think it has been very well established by now that SOMETHING is wrong. From the images provided it isn't possible to tell much - could be a de-adjusted lens, zooming during exposure, kicking of the tripod, unsteady camera holding. Unless some images under controlled conditions - as suggested above - are provided, all is just mere speculation. </p>

<p>no wait! It's the camera, it's taking bad photos! It's has to be, right since you're only using a d70, you should get the d3x, they take the best photos in the world, period.</p>

<p>Sorry, just had to... you all know the whole "hey, nice photo. You must have a good camera eh?" deal... :P<br>

Anyways Beeswax, I first though your wife was zooming as she took the photo, but reading the threads it seems the shutter speed is too fast... I think try out against a flat object at different apertures like suggested to see if it is the lens, which I think so as well. Not the first, nor the last time, a bad lens has come out of a factory...</p>

<p>So many post...OMG.. Ok here's my "best guess" opinion based on this limited information.</p>

<p>1) in the first picture the camera tried to focus on the rope in front of the fence because your wife has it in auto mode and all the AF points are active. "You never know what your gonna get" Since you are zoomed in too close, the effective focus distance is out to far. In other words the rope is too close to be focused on at this zoom range. On the wide end this lens has a minimum focus distance of 3' zoomed in, I'm sure it's out farther than that. I bet she was standing less than 3' from the rope right?</p>

<p>2) in the second picture the AF system chose the grass in the middle of the shot to focus on.</p>

<p>3) At F2.8 the DOF is too shallow for these shots.</p>

<p>4) There appears to be one lens element or group out of allignment resulting in the bottom left corner and top right corners skewing perspective and focus.</p>

<p>Testing:</p>

<p>This is very simple. You tape a page from the newspaper to the wall. Set the camera on a tripod. Use flash, or direct window light, or high iso to get a fast shutter speed over 1/500th. Set aperture to F11. Focus on the newsprint and shoot. Then repeat with progressively larger apertures, F8, F5.6 and adjust ISO accordingly to maintain the 1/500th shutter (or use auto flash). Look at the shot's and read the newsprint. Repeat all these steps at various focal lengths (zoom distances). Make sure the news paper always fills the page.</p>

<p>Advice:</p>

<p>1) if any of the test shots come out nice and sharp that proves the problem is technique. But in this case I think it's a bit of both the lens problem and technique.</p>

<p>2) Send the lens back to Tameron for repair if it cannot be returned. It should have a 6 year warranty.<br /> 3) get her a book on photography before buying any more $700 lenses. I get fantastic shots with several Tamron lenses costing half that. Using Auto modes and multiple AF points creates a lot of exposure/focus errors. It's best to learn the craft and the equipment and make choices for hte camera instead of letting the camera make the decisions.</p>

<p>I think Rob is right. I have always heard that shutter speed should be the reciprical of the focal length. I am inclined to think there is probably nothing wrong with the lens. Crank up the ISO, stop down and fire away. I think you will get the results you want. </p>

<p>You are also making the mistake of shooting pictures of cows and that should be left to professionals. It is much like weddings. Unless you are asked to do it as a favor to a friend (sure you were) you should not as you are bound to have a problem. By the way. Does your wife go by Mrs. Beeswax or does she hyphenate?</p>

<p>She is using a D70. Could it be that the small viewfinder on the D70 is causing part of the off-focus problem?</p>

<p>The lens is very obviously terribly out of alignment. Send it to Tamron for repair. </p>

<p>I will PERSONALLY give 100 bucks to anybody who can duplicate that effect with a good lens.... Man, it's impossible! No shutter speed, no focus, no damned Nikon X-rays-photonic-devastating-starship will solve the problem. The rest is just chatter.</p>

<p>;-)</p>