Problem with Front-focusing 105mm DC - what to do?

Discussion in 'Nikon' started by aaron_d., Jan 12, 2009.

  1. So, I got my 105mm DC lens last week, new from B&H, along with some good advice from folks here on the forum.
    However, bit of a problem. It's consistently front-focusing by about 1-2 inches (on my d80). At f/4 and beyond, it's not that big of a deal, because there's enough DoF to make sure the subjects eyes are in focus. I like it's rendition of skin tones better than my other lenses, but if it's only usable at f/4 and smaller, I'm not sure it's $900 better. BUT at f/2-f/2.8, getting a person's eyes in focus is a crapshoot. I have to aim between their eye and their ear to get their iris in focus. I also set it up on a tripod, just to confirm it wasn't something wrong with my focusing/lens holding technique. The same front focus appears on a tripod.
    So, I'm not sure what my best option is. I see a few:
    1) Keep it, and learn to live with the limitation for now. At some point this year I'd like to upgrade to a d300/700, and may be able to fix the problem with the focus fine tuning those cameras offer.
    2) Return it for another copy. It seems like this is a common problem with this lens, on newer digital AF systems. It seems likely that I'll encounter the same problem with the next lens.
    3) Send it to Nikon for alignment/repair. I've never used Nikon service before, not sure how (if) that would work. It was a new, USA copy.
    4) Exchange it for something else. Not that appealing - I really had my eye on this lens. I like the Defocus control already, and am already using the options it opens up. However, there are certainly other options out there for portraiture. Maybe one of the 85mm's or a fast zoom.

    What do you think? Any advice will be much appreciated.
     
  2. No don't keep it at all and also don't exchange it for something else because is very good lens.
    So just take it to service and tell them to calibrate it or if is possible exchange it for another copy.
    Bacause that with front focus it's not such a big deal and I think the service will calibrate it in about one day if they don't have a lot of work.
    Bye, Luka
     
  3. umd

    umd

    This is a well known issue with this lens, try setting the defocus control ring to f:2.0 front, in my case this cured the problem with some additioal focus tuning on the D300.
     
  4. The focus isn't that far off - just an inch or two. I suspect I could fine-tune, if I had a d300 or d700. However, upgrading to either one of those is still at least 6-12 months away for me.
     
  5. an inch or two is a lot. Exchange it and see if its better, then send it to service if its not. You may want to send it with your camera body too, but check with nikon on that first.
    The lens is awesome, but on a crop body I like the 85 1.4 better. If the first two options dont appeal to you, the 85 is a really good third choice.
     
  6. If the price and condition of the lens are good I would have the lens serviced by nikon.
    The amount of front-focus sounds a lot.
    My lens has a smaller deviation and I just do what Umit suggested, I compensate with a slight twist of the DC ring. Next time I send something for service it will go to Nikon.
    Have fun with this excellent lens. Using the DC feature is a bit of a gamble. I think not trying to overdo the effect will give good results.
     
  7. Exchange it for another copy. On the D300/D700 and up I'd say "dial in -15 AF fine tuning and be happy with a perfect lens/camera combo", but on the D80 you have no other chance.
    I would not keep it. It's the dealer's job to get you a lens that works with your camera. In general, it's a good idea to test FF/BF with your camera while you are at the shop. A focus test chart will help. Focus on the center line from near and an angle of 45 degrees, then take the camera, go in front of the shop and focus on some shop sign far away. Both should be in perfect focus. If focus on the test chart is off, focus on infinity is likely off as well. Don't accept a lens that is off.
    On the other hand, you seem to have bought your lens via mail order, right? Tough question. Sending it to Nikon will be as fast or faster than getting another copy from B&H. Still, I'd request at least another copy from them. If this is a frequent problem, then Nikon does a sloppy job, and B&H is in a much better position to complain to Nikon. You may be lucky and the next copy is OK, otherwise you can still go the Nikon route.
    In general I would not shop lenses anywhere than at a dealer where you can try them with your camera. They may have higher prices, but you get what you pay for.
     

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