Nikon 18-200 AF Fine Tune on D300: Can somebody figure this out?

Discussion in 'Nikon' started by j_w|13, Jan 29, 2010.

  1. I shot both of these photos with my D300 with the 18-200 Nikon lens at 26mm - f/4.5. I tried AF fine tuning on them.
    In this first picture (AF tune @ +10) the image is clear towards the right-center but blurry on the left.
    [​IMG]
    Strangely, with AF tune @ -5, the clarity is reversed from the above picture. It is now clearer on the left and more blurry towards the right-center. Can anyone figure what's going on? The subjects are far enough away where depth of field should not be an issue.
    [​IMG]
     
  2. Where is the point of focus? What was your shutter speed? Solid tripod? Exposure delay mode, (mirror up)? Also, I would have stopped down further than f4.5 to take this image.
     
  3. I focused on the bright building near the center. The buildings are all a few hundred feet away and shot wide angle, so depth of field should be infinite. I wanted to shoot close to wide open in order to tune my lens.
     
  4. Were you shooting these obliquely through a window pane?
     
  5. No, there were shot outdoors on my balcony on a tripod.
     
  6. Hi Paul,
    You probably should use a different test subject under better lighting conditions to tune your lens. Sorry I'm not more help. I'm sure someone else will chime in soon.
     
  7. Oh yes, and be sure VR is off when using the tripod.
     
  8. VR was off.
     
  9. The two look pretty much the same to me. The one on the left has a little more coma than the other, but if you look down in the right bottom corner of the sample, they look pretty much the same. The slight variation between them is probably wind or heat rising between you and the bright pinpoint lights.
     
  10. Good observations, Stephen. There are a lot of possible variables here. Another is the stability of the balcony Paul shot these images from. I live in a 40 floor condominium here in Honolulu and while standing on my 7th floor balcony in my bare feet, I can feel periodic vibrations through my concrete deck. I live close to a freeway and three elevators are constantly traveling up and down within the building.
    Also, I would be interested in seeing an enlargement of a similar area on the right edge. I am still bothered by this image being shot wide open and the resulting loss of edge sharpness at this magnification.
     
  11. The 18-200mm lens is better at f8 or f11. Testing at f4.5 may not be so good.
     
  12. This sort of result was standard for the 18-200mm AF-S VR I once had...... irrespective of focal length, aperture or support. I hope there is another explanation for the issues you are having here.....
     
  13. Jerry,
    Paul is trying to fine-tune his Nikon 18-200mm f4.5-5.6 VR lens with his Nikon D300 body which is a valuable adjustment option available on Nikon's more advanced camera bodies. Generally, you want to perform this fine tuning at a the widest aperture of a lens. However, I believe Paul should be performing this particular procedure under more controlled circumstances. In Paul's defense, this may be the only convenient opportunity he has to indulge in this sort of thing.
     
  14. "This sort of result was standard for the 18-200mm AF-S VR I once had...... irrespective of focal length, aperture or support. I hope there is another explanation for the issues you are having here....."
    I can't say that I agree with your experience, Matthew, at least as to the performance of my very early sample of the Nikon 18-200 f4.5-5.6 AF-S VR.
    00VdjR-215559584.jpg
     
  15. People probably get tired of me saying how this lens, (Nikon 18-200mm f3.5-5.6 V AF-S), gets disparaged too often on photo.net. As a former professional, I can tell you that if I still had the energy and connections, I could sell the above image, and others taken with this lens, over and over again, paying for the lens, the camera and transportation to and from the site and make a tidy profit for the rest of my life and the life of my heirs.
    Granted, had I used a better quality optic, I could have captured an image with better IQ. So what. This lens rocks!
     
  16. This lens rocks!

    Robert, you have missed my point, your particular copy of the 18-200mm lens might rock - mine did not, in fact it was by far and away the poorest optic I have ever used and I've used plenty! I do not need to be a Pro photog. to know that my copy of the 18-200mm AF-S was a complete and utter dud - even after a warranty repair / fix / fiddle / do nothing by Nikon Australia. My point for the orginal poster is that I hope he has not befallen the same blight that I did with this particular lens by purchasing a dud copy - they (dud copies) do exist..........

    I know there are plenty of p.net members with glowing reviews of the 18-200mm lens and they are warranted indeed - my experience was something else.......​
     
  17. I could sell the above image, and others taken with this lens, over and over again, paying for the lens, the camera and transportation to and from the site and make a tidy profit for the rest of my life and the life of my heirs.​
    so the 18-200 will support one's retirement fund and support one's offspring's financial needs forever? that wouldn't be hyperbole, would it?
     
  18. This is the reason why not to use lenses such as the 18-200 ;-)
    It looks like the plane of focus isn't exactly parallel with the lens. It can happen either as a manufacturing defect or something has gone out of alignment later. More tests would be needed, but frankly I wouldn't be surprised if this was the cause.
     
  19. The building on the left seems to be much further away than the building on the right.
    The difference in sharpness between both shots seems greater in the building on the left. The building on the right looks to me almost the same in both shots.
    If the point of focus is closer in the first shot wouldn't that account for the difference?
    Hard to tell though at this resolution and with my eyes!
     
  20. Jerry wrote [The 18-200mm lens is better at f8 or f11. Testing at f4.5 may not be so good.]
    That is the entire issue.
     
  21. Looks like coma smearing to me. A product of focal length, aperture, and unavoidable overexposure of bright light sources on a dark background placed at the edge of the frame. Seen a lot worse examples than that, including my old 50mm at f1.4
     
  22. ShunCheung

    ShunCheung Administrator

    Paul, I would retest your lens capturing images of a flat brick wall. If you want your camera to be absolutely parallel to the wall, tape a small mirror in the middle of the wall and align your camera so that you can see the image of your camera from the mirror when you look thru the viewfinder.
    While it may be too much to expect corner-to-corner sharpeness from a lens such as the 18-200, at least it should be even on all corners. If somehow one side is sharp but the other is not, and after you re-focus a different side is sharp, it may be an indication that your lens axis is not totally perpendicular to the sensor plane. That is the symptom that either your lens is not aligned or the mount on the body is not aligned. Once I drop my camera + lens and the mount on the lens is just slightly bent, and that was the symptom I observed.
     
  23. it seems like the d300 is laboring with the af fine tuning feature with the 18-200mm.
     
  24. Ramon,
    With all respect, no. The OP is testing a lens for edge-to-edge focus on a 3D topic shot wide open.
    The test is flawed. Follow Shun's advice above.
     
  25. might have been better if the test/fine tuning subject or center of focus was the wide building with many windows.
     
  26. Eric,
    "so the 18-200 will support one's retirement fund and support one's offspring's financial needs forever? that wouldn't be hyperbole, would it?"​
    I was eluding to stock photo agencies.
    However, a claim that my images generated by my Nikon 18-200 f3.5-5.6 would support my spendthrift heirs financial needs forever would indeed be hyperbolic. :)
     
  27. Matthew,
    Robert, you have missed my point, your particular copy of the 18-200mm lens might rock - mine did not, in fact it was by far and away the poorest optic I have ever used and I've used plenty! I do not need to be a Pro photog. to know that my copy of the 18-200mm AF-S was a complete and utter dud - even after a warranty repair / fix / fiddle / do nothing by Nikon Australia. My point for the orginal poster is that I hope he has not befallen the same blight that I did with this particular lens by purchasing a dud copy - they (dud copies) do exist..........​
    I am sorry to hear of your truly disappointing experience with the Nikon 18-200mm lens. I must say that I have encountered a few poor Nikon lens samples myself, but nothing Nikon was not able to put right after one or two visits. It's unfortunate you were not given the opportunity to appreciate some of the advantages of this lens. I would have asked for a replacement, but perhaps you were understandably fed up with the whole affair at some point.
    I did miss your point. Sorry.
     
  28. I was eluding to stock photo agencies .​
    stock agencies arent what they used to be, robert. the proliferation of internet content has oversaturated the market, and some newspapers are now drawing heavily on "free" content from flickr et. al rather than paying for freelance photos. even NatGeo now has a reader photo section.
    in any event, if you could sell that image and make a buck or two, more power to you. but it looks a little washed-out and lacking in contrast to me. maybe it just needs a pola filter, or maybe it's the 18-200's oft-mentioned softness.
     
  29. Also, http://www.dofmaster.com/dofjs.html tells me DOF is not an issue when the background is far away.
     
  30. ShunCheung

    ShunCheung Administrator

    Paul, if you would like to find out whether your lens and camera are fine, you need to reshoot with a flat subject that is completely parallel to your sensor plane.
     
  31. Paul , with all due respect. If you are attempting to test/set the focus of you lens, do as Shun suggested. Otherwise, you are wasting your time. IMHO. If that is not what you are doing, my apologies.
     
  32. in any event, if you could sell that image and make a buck or two, more power to you. but it looks a little washed-out and lacking in contrast to me. maybe it just needs a pola filter, or maybe it's the 18-200's oft-mentioned softness.​
    I think your monitor is out of calibration.
     
  33. i hear you, peter.
     
  34. What Shun said.
    Another method, tape newspaper, say the stock prices for the day, to a wall. Get absolutely perpendicular to the paper, and then go through a series of shots with the progressive focus adjustments changed in menu. Put the lens way out of focus before each autofocus shot, for each setting.
    You should have a series of photos, one at each setting. You can choose and embed the sharpest in the camera.
    I cannot see how one could fine tune a series of focus settings in night, city scape with infinite focus points out there, with different distances across the image.
    There is a tool on the market specifically designed for fine tuning lens autofocus in the camera. "Lensalign." It's well spoken of, but not in my budget, or needs, at this time.
    http://www.rawworkflow.com/
     
  35. ShunCheung

    ShunCheung Administrator

    I would only use newspaper as a test subject/target when I am testing a macro lens. Otherwise, it is just too small a subject and your camera position has to be very close to it. Most regular lenses (i.e. non macros) are not going to perform very well in the macro range. You may see major distortion and lack of sharpness.
     
  36. Shun are you saying that AF fine tuning is as simple as photographing a contrasty subject, like a brick wall, perpendicularly at different AF fine tuning points and choosing the most focused image is all that's necessary AF Fine Tune a lens?
    If so, that's the most simple and concise explanation I have heard. I've been reluctant to even check my lenses because I've read that you need special focus charts and have to be at 45 degrees, etc.
    Mel
     
  37. I had an 18-200 once. Took me 4,000 or so pics to figure out it wasn't me... the pics were not good. Had it sent back to Nikon. It came back tack sharp. A month later, it was all wrong again. It's sitting on the dust collectors' shelf. Bought a few prime lenses and won't go back to DX format amateur lenses.
     
  38. Thanks for all your responses. I think I am simply going to stop down and not have to worry about focusing issues. Because I'm going out on a week long vacation, I wanted the versatility of a large range zoom and not having to carry much equipment. Also I'd rather sacrifice a little in picture quality than miss a shot changing lens.
     
  39. ShunCheung

    ShunCheung Administrator

    The simple way to fine tune AF is to take a few samples tuned to different settings and see which one is the sharpest, and then set to the setting what gives you the sharpest result.
     
  40. The OP can help us all by telling us what were the focus settings on his D300 body and in the menus. These beasts offer many focus options. Setting it up one way and expecting it to behave another way can be very frustrating, as in my case with the D200:
    http://www.photo.net/nikon-camera-forum/00Upbn
     
  41. The stated focal length was 26 mm and it is clear that both subjects are at a quite long distance from the camera. Now focusing may be very sensitive even at these settings, but it's extremely hard to imagine that DOF would be so shallow as to put only one side in focus at a time. Also forget the brick walls; a modern building with a glass face is better since it is much easier to align the camera when you can look at your mirror image reflecting from the facade.
     
  42. The flat wall test will give you alot of info about your lens quality and alignment issues, however if you want to use the D300 to dial in the focus of this lens I would suggest shooting the wall at 45 degrees and using one of the many free focus calibration targets on the web for a focus target such as this one: http://focustestchart.com/chart.html This set up will tell you better if you are front or back focused as you use the D300 to move the focus point during a series of test shots. Once confident of your focus point the flat wall test will be more revealing.
     
  43. Just got back from a seven day trek in Havana. This 18-200 lens was the worst thing that happened to me on the trip. Nearly every image shot above 100mm was soft, soft, soft! It would make you scream. It didn't matter if you used a tripod, shot at a fast shutter speed, or used a middle aperture. This lens utterly ruined my images. Luckily I brought my Lumix P&S as well. Images were much better at the longer length.
     

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