Backfocus on just 2 lenses.

Discussion in 'Nikon' started by raymondc, Dec 11, 2009.

  1. Hi, I haven't been totally happy with 2 of my lenses, the others has been fine. I have tried focus charts and I have tried real subject ie., wide open at the longest FL at someone's eyebrows and then evaluate on the computer - shot on tripod.
    The results been consistent on my D70 body which has been repaired at Japan Service Centre where it was bought. It was repaired for backfocus and BGLOD and maybe other assoc work. It's been consistent with my D2h body as well bought used.
    The lenses affected are, 80-200mm f/2.8 bought in Asia without the luxury of 5yr USA warranty. The Tamron 28-105mm f/2.8 that was given free with my used D2h body, this lens does have some scratches on it both the front and rear element.
    Images attached are crops at full view, I used the middle AF sensor on the D70 - AF-S, Singular frame. RAW.
    Maybe I should send this lens to New Zealand Nikon to have it evaluated for a small fee (not free like the USA) and then see what their evaluation is. How much can backfocus repair cost? As for the Tamron lens when I zoom into fullsize, it appears soft all over, maybe it is the result of the scratches on the glass.
    As a side question, does mis focus issues have much a say on the end result? Ie., post processed, and then printed at say a modest 8x12. Say it was shot wide open aperture and at the longest FL.
    Cheers
    00VEak-199951584.jpg
     
  2. 80-200mm f/2.8D Nikon lens. Both images at f/2.8 at the len's longest FL. Tripod used.
    00VEal-199951684.jpg
     
  3. I'm not a pro Ray, but it looks to me like there is some camera shake with the Tamron shot. With the Nikon, since you are at f2.8 your depth of field is very shallow leaving only a small area in focus (you can clearly see the difference between the "1" and the "2" in 12. However, both shots seem very noisy. The D70 doesn't handle ISOs above 400 very well, especially in dim light. To me it looks like you need to try these lenses on a tripod in good light and more general settings.
     
  4. They were actually shot at ISO 200 RAW. Shutter speed of 1/320.
    Will redo the test. Maybe the 3D matrix meter was fooled by the whiteness of the calendar.
     
  5. Here is the Tamron shot again. All the shots on tripod. This particular one ISO 200 1/250. 105mm at the longest FL. It is just soft all over. All the images this lens has captured - test charts or anything like portraiture when zoomed in. When it is fit screen size, it seems sharp but not when it is zoomed in.
    00VEc9-199961584.jpg
     
  6. This is the 85mm at f/1.8, much sharper. Shot at same time with the Nikon 80-200mm and the Tamron.
    00VEcD-199961784.jpg
     
  7. Wow, I think you answered your own question Ray. The Nikon looks great, but something's wrong with the Tamron. There could be a lot of things happening, does it try to autofocus? You might try a manual focus and see what you get.
     
  8. I still have to retest the Nikon 80-200mm. The above great test was the Nikon 85mm :-/
    I don't use the 80-200mm much, not into events or sports. But I swear that my former bought used 80-200mm f/4.5-5.6 was sharper than my bought new 2.8 version (!).
    If the Tamron is stuffed, how much practical use is it you in view? Ie., PP, printed 8x12. I don't do much events, but if I did the odd one for my camera club is it passable? A fast mid zoom lens hasn't been a importance for me.... saves me buying one, lol.
     
  9. If you can't get focus on the Tamron it's of little use, of course. You could check with Tamron about a repair. However, if autofocus isn't working because the contacts are dirty or something easy like that you can take care of it yourself. The 80-200 is a great old lens. I'm curious to how the ruler test will look. I suspect your concern that you got a poor version of the 80-200 is right. I've had good and bad luck with versions of Nikon lenses. I just read a review of the 70-200VR where the tester got very different results from 4 different versions.
     
  10. The Tamron AF certainly works. If you manually focus it out of focus, AF just engages and snaps on and what you see in the viewfinder is definitely in focus. Maybe because the lens is scratched in the front and rear glass element. But then again it was free from the D2h purchase. It was used by a sports photographer, the D2h had nearly I think if not just over 100k shutter actuations. My own D70 from new is still under 10k lol.
    When you guys buy a lens new or used, do you think about if the lens is going to be aligned correctly? Or is it safe to ignore that and if you need to service it, chances is it is the odd time only?
    If you don't zoom into it, it is not too bad but then again I haven't printed any pix with that lens yet.
    Cheers
     
  11. The 80-200 AF-D has known issues with backfocus on digital bodies. Some users report near flawless performance with this lens while others, such as myself, have auditioned multiple copies without finding one that will work acceptably. This anomaly crops up at focal lengths beyond ~135mm at distances approaching the minimum focusing distance, but can, in some cases, still be present at distances around 30 feet.
    Back in the day, Nikon's cure for this was to send the disgruntled user a 80-200 AF-S. No such luck now, but a refund may still not be out of the question depending on the mood of your local Nikon authority.
     
  12. Thanks for that I may also shoot a frame on slide film off my F100, just waiting for the sun to come out, I am in the southern hemisphere. Summer yet it is cloudy, no wonder they call us 4 seasons in one, rain all year round. Our summer Christmas even has a reputation of being wet.
    I bought this in HKG, now I am in NZ. Fat chance.
    Bit of a shame really when I bought the lens after going to digital. Nikon still sells the AFD lens new as of now I think.
     
  13. 80-200 is probably OK, this is a known issue with the lens (wrong focus on close distances).
    As for the Tamron - well, I've been researching it lately (I'd like to have a zoom like that) and I've seen nothing but bad experiences and rant - way too soft and shitty.
     
  14. Ray, check out this thread and the article it directs you to. Very enlightening!
     
  15. Jim, thanks for sharing that article. It confirmed a lot of stuff I had suspected for a long time. It should be mandatory reading for anyone making a post about their equipment. That made my day, thanks again Jim.
     

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