MF lenses on a Nikon dSLR, don't trust the viewfinder??

Discussion in 'Nikon' started by photo5, Apr 2, 2007.

  1. Am interested to find out of there is a consensus not to trust the viewfinder
    when using MF lenses on a dSLR. Someone said in another post to use the focus
    confirmation, not the viewfinder. I haven't noticed a problem with my D80 and
    the Nikon 55mm f2.8 Micro-Nikkor though I haven't done any real close up testing.

    Does anyone know which Nikon dSLR this applies to, or all of them? I have
    noticed a discrepency with this but always trusted the viewfinder more than the
    electronic focus confirmation green dot.

    Thanks,

    Dave
     
  2. I have two MF lenses for my D200. They're a 50mm f/1.4 & an unusual 105mm Macro f/2.8

    I seem to do OK just looking through the viewfinder, but I'm probably installing a Katzeye to help me with MF as it's a bit hard to be sure on the focus.

    My only concern is that with the Katzeye metering seems to be an issue. My D200 seems to underexpose most of the time, based upon the histograms I review especially. So adding the Katzeye will add to that. They admit that the Katzeye does create a problem with spot metering especially.

    I have to consider the green dot for focus, but for me I didn't even notice it until the other week - after someone pointed it out to me. It's not placed in a convenient spot for me. Since I wear contacts & need reading glasses to help with anything close - the green dot is simply out of view for me.

    I'll have to try that, but for macro where focus is so up to the photographer, I don't think it will make any difference.

    I'm using the viewfinder as focus confirmation at this time. Will have to consider other options if I have a problem.

    Lil
     
  3. Trust the viewfinder, and your optometrist (~|~).

    Perhaps do not trust the green dot focus confirmation light produced from the Electronic Range Finder, (it was more problem of that on the D70 though - D200 should work better ?), with Manual Focus lenses.

    Read more from the lengthy discussion on the same subject:

    http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00KZ1S&unified_p=1
     
  4. We just talked about this, but this fact bears repeating. No matter how good your eyes are,
    most focusing screens on modern DSLRs don't resolve enough to show you the difference
    between f2.8 or so and wide open at f1.8 or f1.4, so you could look in focus but not be. I
    suspect that if your camera is functioning okay (I tested my D50 and it is) then you can trust
    the green dot. Also, at 50mm f1.4 or f1.8, very little is in focus in the first place. That will
    have nothing to do with your focusing screen and everything to do with the physics of the
    lenses you are using.
     
  5. Frank, I mentioned in another post that the VF can not be relied upon until you are certain that there is no misalignment with what you see and what the actual focus point is.

    My D70 is dead on for AF, but when manual focusing, what I saw was in fact not in perfect focus as what the camera saw - via the green dot. I don't know the exact term, but the mirror or something was not aligned.

    It was only when I tested for a back focus problem that I realised this. That is, the AF as well as the green dot was perfect, but the VF was not.

    I adjusted this thing inside the camera, but it is still not 100%. That's why I rely mainly on the green dot.
     
  6. All I can say is that my D200 with a KatzEye (+OptiBrite) focuses dead on with the 50/1.2 wide open even at close distances. The same holds true with the 50/2.8 Micro-Nikkor. Highly recommended combination! With the original focusing screen it more or less worked with the green focus confirmation but I found it to be impractical since there is a small delay.
     
  7. Nico,

    glad to hear the focusing is dead on. What about metering. How does your D200 preform there? Katzeye writes about the changes in exposure - what's your take?

    Would appreciate your feedback as I'm actually waiting to receive my Katzeye in the mail to install myself.

    Lil
     
  8. I disagree with Peter's post. Please read my comments at the link posted by Frank. In my experience, your eye and the viewfinder (on a D200) produces more accurate focus than does the green dot. This was proven to me with the following mf or AF lenses all used in mf mode on my d 200: 55mm, 105mm, 200mm, 300mm and 500mm. Joe Smith
     
  9. I created a thread about focusing issues with mf lenses and the D70. You can check the accuracy of the green dot and the viewfinder by doing a newspaper test. I discovered my camera was like 1/8-1/4" off with mf, af lens was a little more accurate. In the end I decided that there were other issues that were more responsible for the lack of sharpness and for the most part the green dot is pretty accurate even with mf lenses.

    I'm always hesitant to condemn equipment because most of the time incorrect technique is at fault. Take for example the mf 55mm micro, focuses differently than most lenses. As you approach infinity the focus ring changes more with less rotation. Since this is a macro lens it makes sense that the focus sensitivity is at the other end. With an open aperture the depth of field decreases and so does the margin for error. Throw in the focal length increase due to crop factor (its really a 83mm) opening the door for camera shake if you at 1/60. If you're shooting indoors in a low light low contrast environment that make focusing all the more difficult. Not to mention Nikon intentionally leaves off sharpening and contrast camera processing so images tend to look soft to begin with.
     
  10. SCL

    SCL

    I think if your vision is perfect or you have corrected it to be perfect consistent with your viewfinder, you could trust both it and focus confirmation. However, many people don't periodically check their diopter adjustment when changing lenses, and end up slightly misfocusing when using manual lenses. In my experience with manual macro product shots, I've found it pays to double check everything and when I do, generally the green dot is consistent with what I see in the viewfinder.
    BTW I frequently use manual focus lenses with both my F100 and D100.
     
  11. I think you still need to rely on the green dot to get more consistent focused shots. Often a picture may look focused for you, but when you view it in your PC at home, it's actually not that sharp.

    I think the best way to do is, as mentioned in other thread, find the "middle point" where the green dot starts and ends - in between that tiny area, look for the best focus according to your eye.
     
  12. I recently had my D200 corrected due to a back focus issue. Focus had to be altered by about 50 micrometers. Furthermore, my view finder had to be corrected as well. I've put in a Katz-Eye Optibrite and the split prism indicated focus in the wrong place.
    As if this weren't enough, the exposure meter had to be calibrated as well. Although I'm using a Katz-Eye, the camera was over exposing by 2/3 of a step.
    The conclusion of this: don't expect your brand new D200 to be perfect from the factory. Have it checked.
     

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