D-70 and 80-200 f2.8 backfocus issue

Discussion in 'Nikon' started by nino, Nov 27, 2004.

  1. Has anyone had any focusing issues with this combination? A lot of
    my shots seem to be consistantly focussed slightly 'behind' the
    subect (ie: eyes and cheeks soft, but hair or collar behind sharp.)
    I have not had this issue with any other of my lenses. I have
    checked the so-called 'back-focus issue' and it seems to be ok on my
    camera (using a 50mm). Could it be the lens not being calibrated
    correctly of might it be a body/lens issue?
    Any real advice appreciated.
    I have attached and example of this issue. I DEFINITELY focused (AF)
    on the front eye,, but as you can see focus lies more to the back
    eye and shirt collar behind. I always use AF because the d70's
    viewfinder is impossible to focus

    n.t.
     
  2. I have similar problems with my teles (though I don't have the lens in question). I suspect the focus sensor is larger than we think and it will focus on the part of the image which is under the focus sensor but has good texture. In film cameras, the sensor areas are so small relative to the frame that these issues don't appear.

    A second possible reason is that you may not have waited for the camera to find its final focus point. I often notice that the camera has to be let some time to finalise the focusing before recomposing in S mode. Nowadays I use AF-C and the thumb button for activating AF. It seems to work better and I avoid the camera suddenly deciding that it needs to focus again.

    It's a real problem with the camera though - and one reason to continue to use film.
     
  3. You are describing precisely the problem that made me give up on digital. I briefly owned two different D70's last spring. I noticed the problem with an image like yours, focused on the front eye with a narrow depth of field set up, the other eye and ears were sharp. I then did tests with the 80-200 f/2.8, and also with a 300 f/4, with the camera on a sturdy tripod, the one I use for 4x5. I placed two pens on my deck, about an inch apart and focused on the near one with the lenses wide open and a fast shutter speed. The far pen was sharp every time, with both lenses. I also did some closer tests with a shorter lens, a 35-70 f/2.8 and my 50 f/1.8 with a target I found on the internet and had similar but less problem. Images made with the kit lens at f/8-11 looked good, as one would expect with the increased depth of field.

    My dealer was reasonable, I returned the camera within the 14 day trial period. I have been tempted but have not yet been willing to spend $1,000+ on a body + permanent film (that's what a digital SLR really is) combination that cannot match my film camera body (currently worth perhaps $100).

    I find the financial argument for digital to be moot since I frankly have no idea what people do with the thousands of images they make with these cameras. To me it seems a bit like placing a million monkeys on a million keyboards and awaiting Shakespeare's plays.

    Quantity is not everything.

    Good luck.

    Eric
     
  4. EricM

    EricM Planet Eric

    "It's a real problem with the camera though - and one reason to continue to use film."

    unreal.
     
  5. As a result of your post I pulled out my entire collection of AF lenses which consists of: a 12-24 f:4; an 18-70 f:3.5-4.5;a 60mm f:2.8 micro; an 80-200 f:2.8 and a 300mm f:4, along with 1.4 and 2X Tamron SP 300 TCs, two D-70's my tripod and my grand daughter's trusted teddy bear. I focused on teddy's left eye and shot wide open, at f:11 and fully stopped down for each of the lenses. I shot the zooms at shortest, middle and longest focal length. I also shot the 300 with the TCs. In each case I was at or close to, the minimum focus distance for the lens. In every case, teddy's eye was in best focus. Surprisingly though, the 80-200 seemed to be the softest overall. Since I don't have a remote release, camera shake may have been an issue, especially at the longer exposures. (I was shooting by north light on a rainy November afternoon in the northeast)That notwithstanding, I don't see any focus problem across the range of lenses I own on either body.
     
  6. Bob, did you use AF? Did you just point the sensor to the eye, focus and shoot or did you check with the viewfinder that the eye was in focus.

    A part of the D70 problem is that in a real situation the camera has to follow slight movements of the subject and this seems to be something it can not do very well. I also get good focusing results when I shoot immobile subjects (in fact they're as good as they can be). But that won't help me with subjects that can move a bit, like people standing.
     
  7. Ilkka Nissila: After a reasonably intelligent answer to my question i was disappointed to read your 'another reson to stick with film' comment. hmm Perhaps we should all go digital because film expires or fogs with xrays?
     
  8. I've heard a lot about this back focusing problem with the d70. Now I understand what it is. You could use manually focus but then you'd only have yourself to blame for back focusing problems.

    I was thinking of going digital because I'm tired of dealing with film expiration, running out of film, waiting to take pictures to complete the 1/2 roll sitting in my camera, negatives getting scratched or lost, wondering before development if i have enough good pictures to warrant doubles... Instant feed back is also very nice too. But for now I'm holding back on a professional dslr.
     
  9. Peter, i initially had the same thoughts as you and thought i might buy the low cost D70 body and try it out, seeing as i have a full package of Nikkor lenses. I must admit since acquiring the DSLR about 8 months ago i havent shot a single roll of film. (except for my Mamiya) There certainly are some teething problems with these 1st/2nd generation DSLRS but i have found the benefits outweigh the problems at least two-fold.
     
  10. Nino, since Nikon doesn't make a digital SLR (with 6 MP or more) which can take consistently focused images, I will continue to use film cameras (which curiously produce close to 100% correctly focused images of even slowly moving subjects) until such a digital camera becomes available. After one becomes available, I may stop using color film. What is so un-intelligent about this?

    I have never seen the effects of x-rays on film. But neither have Kodak scientists with moderate (less than 20 times) exposure to x-ray scanners (given slow or mid speed film). And expired film? I just throw it away. With the cost of travel and equipment, film costs have never crossed my mind as relevant.
     

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