Sigma 18-200 OS, anyone?

Discussion in 'Lens Lust' started by goofball, May 12, 2007.

  1. Has anyone seen a review or know someone that has this lens yet?

    I see that a store in Canada has them listing for $629 CAN!!! That's $170 cheaper than the Nikon equivalent.

    I'm not crazy about f/6.3 but I'm wondering whereabouts it turns to that. I have a 70-300VR that I don't mind mounting so if it's too slow, the 70-300VR will see action.

    http://www.thecamerastore.com/ProductDetails.aspx?productID=32488

    Anyone? Very tempting!!
     
  2. I have the non OS model which I assume is pretty much the same thing
    Heres what my D70s reports
    80mm = 5.6
    100 = 6.0
    200 = 6.3
    Its AF time is mediocre, Not nearly as bad as the Sigma 70-300 APO DG Macro though, And its also slightly faster than the 50mm f1.8 AF-D.

    Image quality is decent from 18-135mm, After that it gets a little soft and loses a lot of contrast.

    If your buying new its probably worth is to get the Nikon (if you can find it), The Af-s alone would probably make it worth it.
     
  3. > I have the non OS model which I assume is pretty much the same thing

    The 18-200 OS has a completely different optical formulation, evident even from the specifications (18 elements/13 groups/72mm compared to 15 elements/13 groups/62mm), so I wouldn't assume that the results will be the same.
     
  4. Well i hope that they improved it, but since its still 3.5-6.3 I can't imagine it was that groundbreaking of a change, the 72mm filter seems a large jump though, I wonder why.
     
  5. weiran

    weiran

    966
    Jan 2, 2007
    Nottingham, UK
    I'm dubious about the OS Sigma have, I know it's nowhere near as good as Nikon's VR.

    A better bet may be the Tamron 18-200 if you don't want OS/VR, it's supposed to be optically as good as the Nikon, but again focusing will be quite poor.
     
  6. That's not the experience of anyone I know who's tried the Tamron 18-200. It is much softer at both ends of the focal length range than the Nikkor.

    I'm not sure that the OS is all that much worse than Nikon's VR. The one time I shot an 80-400 OS, I found its OS to be pretty much good for what it claimed: two stops. My experience with VR lenses (18-200, 80-400) is that they are both a little optimistic. The 18-200 seems really good for about 3 stops, sometimes four, and the 80-400 seems good for 2 stops, occasionally three. I wouldn't call "occasionally an extra stop" a big difference. I certainly don't feel that I could count on it.
     
  7. weiran

    weiran

    966
    Jan 2, 2007
    Nottingham, UK
    I'm sure someone on here said the OS in the 80-400 was quite poor and he/she got better shots with it turned off? Hopefully someone can clarify that point.
     
  8. That is certainly not the general experience. It definitely was not mine.
     
  9. That was probably me.:redface:

    Even with my second copy of the 80-400 I still have issues with Sigma's OS. Often enough I couldn't get tack sharp images at 400mm (sharp enough that you couldn't see the difference when scaled down, but visible at 100%) and wondered why. I made a series of tests, also repeatedly, that showed that, for example with 400mm, 1/320s (f8) I could get tack sharp images hand held without OS - in bright light of course. Just switching OS (same shutter speed, same subject, no refocussing) often gives a very slight blur that makes the result less sharp.
    I did really lots of these tests because it's obvious that shooting such a lens requires some practice/technique and I would be the last one who claims that his technique would be flawless. But now I'm quite sure about that and how to tell apart mere softness from motion blur.

    For slow shutter speeds where handholding without OS would introduce heavy motion blur I think it will so its job, but in reasonable lit conditions (as described above) I found it to make the picture worse often enough.

    Apart from that it happens quite often (both copies I had so far) that the OS goes haywire heavily shifting the lens group sideways to its mechanical stop (read: heavily vibrating, sounds like Brrrrrrrrr) in a diagonal way. The whole viewfinder image heavily vibrates. Sometimes it recovers from that, sometimes you'll have to release the shutter button, wait, then start again.
    You can imagine how much this helps to capture some action....:mad:

    I'm not sure if you can feel the foremost slight/subtle vibration at the lens barrel while (hand) holding the lens, sometimes I thought I could.
    For the latter one you would definitely feel (view, and hear) the lens mechanics vibrate. Since my second copy also shows that behaviour I fear that this is some inherent shortcoming of Sigma's OS, not just a defect on my lens. Very well probable also an incompatiblity with my D200, who knows. (I think I experienced this with my D70 also, but more rare.)

    I also have a 70-200VR and the reliability of Nikons VR vs Sigma OS (at least that one of the 80-400) is a day/night difference for me.
    The VR never went haywire and always gave sharp images with any shutter speed so far. (Apart from that it's also more silent.)
    Only difference is that the Nikkor is a 200mm while the Sigma is a 400mm, so I'm partly comparing apples and oranges here as I do not know how well VR works at 400mm (for example in Nikon's 80-400VR) compared to Sigma's OS. Would like to compare both, though. :smile:

    This is pure speculation(!!) but I believe the fact that for years Sigma had only one OS lens, and the fact that the 18-200 OS is announced for many months (nearly a year?) and still(?) not shipping, tells something about Sigma's OS. I other words: I think they know their shortcomings very well.

    Now if the lens is actually being shipped and someone can get his hands on one, please prove me wrong, but for now, I would say Sigma's OS is nothing to write home about.

    Curious about Tamron, I heard they announced a VR/OS/... lens as well.
     
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