Problems with Nikon 135mm f2 DC

Discussion in 'Nikon' started by todd_hendon, Jan 27, 2011.

  1. Hi Everyone,
    I was extremely excited to receive my long awaited 135mm f2 DC lens. I popped on my D7000 and started taking shots. For some reason, many of the shots seem a bit soft. I have taken photos at f2 and f2.8 as I am looking to get the nice Bokeh that I have read about.
    Some of the shots were in lower lighting but I used a tripod to minimize any camera shake. I have read so often how sharp then lens is and I'm just not seeing that sharpness. I am taking the photos in RAW at the full 16 megapixel size that the D7000 delivers.
    I'm just wondering if it may be my technique or whether it is possible I received a 'non-perfect' lens. Am I expecting too much? Do most images look soft at 100% when using 16mp?
    Any suggestions/recommendations would be helpful.
    Thanks,
    Todd
     
  2. THe DOF on this lens is measured in millimeters when you are shooting at F2 or 2.8 and close focus, so make sure its focused on exactly what you want to be sharp. Putting a camera on a tripod might keep the camera still for low light shots, but if you are photographing a living being, or something that can move, you might have subject movement. Are you sharpening the photos in a processing program like Photo shop? If not then you will never see true sharpness. If you can post a photo , it will help us find the problem.
     
  3. The 135/2 DC performs best on FX and stopped down a bit, like f/2.8 to f/5.6. Using it on a very pixel-rich DX camera probably results in disappointment especially at the wider apertures f/2-f/2.8. Also, getting the focus spot on can take some effort.
     
  4. Might be worth trying some AF fine tuning to see if you can hit the sweet spot. Take a photo of a yard stick at 45-degrees from the lens axis. Carefully focus on the 18" position, and then study the results to see where the sharpest point is.
    Keep us posted, this lens is on my "short list".
     
  5. Todd, in addition to the DOF of this lens being very shallow at close distances, one must also understand how to use the DC adjustments to take full advantage of this lens's potential.
    Please make sure that the DC ring is in the dead center to use the lens as a conventional 135mm f/2 and get the best sharpness out of the lens. To get the best bokeh out of the lens, you will want to move the DC ring to the left and set it at the f-stop you are currently using. If you go beyond the f-stop you are using, the lens goes soft, as if you had a soft focus filter on it.
    EXAMPLE: You are shooting a portrait at f/4. You can control the background bokeh by turning the DC dial to the left one, two, or three clicks (2, 2.8, 4). Adjust to get the bokeh effect you desire. If you go beyond 4 to the 5.6 setting, your lens will soften and blur some of the in-focus objects, giving you a soft focus look.
    On a side note, my 105mm f/2 DC is sharpest at f/5.6 and f/8 with the DC dial set at dead center.
    Hope this helps,
    RS
     
  6. I don't have much to add, other than agreeing with the existing suggestions, but I'll confirm that - especially with DC set to non-neutral - this lens seems to confuse the autofocus system (for me, it usually front-focuses). I never got around to setting the fine tuning on mine, but it's certainly worth a try. Different apertures and DC settings might require different offsets. IIRC the manual actually talks about manual focus when using non-neutral DC. I can't vouch for 16MP-level sharpness, but it seems pretty okay to me (if not very contrasty) on my D700, with the right focal plane. Good luck with the new toy - the bokeh is lovely.
     
  7. I completely agree with Ilkka, this lens is soft until stopped down. Ours was useable @ f/4, but I wasn't happy till f/5.6.
     
  8. I will point out that I use the 105mm f/2 DC, not the 135mm, and it is tack sharp at f/2.8. You just have to understand how shallow the DOF is and how to get the most out of the lens as I described in my previous post. It took me literally 500 shots to really understand how this lens works and how to squeak all of the potential and quality out of it. I shoot a D300s and I will admit that the lens performs better on film and FX format DSLRs.
    Keep in mind that I do not sit around and test lenses all day long nor do I shoot photos of grids to test sharpness and distortion, nor do I shoot white pieces of paper to test light falloff. I'm talking about real life shooting. I've never used the 135mm because it is so hard to come by and I find it a bit long for portraits. I'd expect similar results, if not better bokeh, out of the 135mm as I get out of my 105mm.
    The only issue that crops up from time to time about this lens is it's LoCA, which I have learned to live with since the positives about this lens greatly outweigh the little time I need to fix a bit of purple/green fringing in Lightroom/Photoshop
    RS
     
  9. Apart from potential lens issues, how do you view and judge the RAW files?
    If you use ViewNX 2, click the RAW button to see the image with a picture style (which includes sharpening) applied. Else, indeed 100% shots may seem a bit soft, even when viewing files of properly focussed lenses at their best apertures. I use the Nikon software, and see strange differences in the amount of sharpening in the full screen view prior to clicking that RAW button. Some (older) lenses seem disadvantaged, and show their full potential only after clicking that button. Strange, but then again, many things are strange about Nikon's software.
     
  10. I've done a lot of research on this lens after receiving it for Christmas and I can tell you that it's performance wide open varies greatly with the conditions of the lighting. My recommendation would be to shoot some test subjects under lighting that is more "contrasty." My initial shots wide open were done indoors under tungsten lighting and I have to say that I was disappointed. I almost returned it when I suddenly found myself getting very sharp f/2 shots with window light. I was completely confused since I've not had a lens perform like this before but the quality of the light really does seem to matter with this one. I don't know that I would shoot a professional gig at f/2 but I know that with my copy I can shoot pretty safely at even f/2.5. Here's just one example:
    http://www.flickr.com/photos/davidpinkerton/5365135843/
    I also posted a whole bunch of links related to this lens here:
    http://www.flickr.com/groups/857794@N23/discuss/72157625614186455/
     
  11. I suggest a well-executed focus test shooting at 45 degrees to the target. Read-up on the technique before embarking. Use self-timer to make it 'shake-free' and exposure delay to negate mirror vibration, esp at slow shutter spds. Be aware of the precise area being detected by the AF sensor(s), esp the cross-type.
     
  12. I have this lens and camera, but I use the lens with a D700. I really like it. There are few things I can think of that would cause an unsharpness issue. Make sure any checkout is done with the DC control zeroed and the other switches set where they belong. Testing should be done with a tripod and a remote release or the camera's self-timer, and the AF set to single-servo with one central focus point selected. Auto-ISO should be switched off, and the camera tested in 'A' or 'M' mode, but not using manual focus for the body or the lens. I agree with David Pinkerton about the light quality issue.
    • Make sure you're not closer than the minimum focus distance (seems obvious, but worth mention in the interest of thoroughness).
    • Shooting RAW can look unsharp since no sharpening is applied to a RAW file by default, so sharpening must be applied in post-processing or the image will look soft by default.
    • Motion blur - this lens has an equivalent angle of view of a 200mm lens on 35mm film (202.5mm actually), and it hasn't got VR. Good shooting technique is essential, as is using a minimum shutter speed of 1/200 sec. when shooting hand held with a DX camera. The slightest motion can blur the image and make it look soft. Raise the ISO if necessary to achieve proper shutter speed. It takes concentration to shoot it properly on my D700. I imagine it'll take even more to shoot it on a D7000. I'll have to give it a try soon.
    • Shallow depth of field - often I'll meter and focus, lock them (AE-L and AF-L), recompose and shoot. The depth of field is so shallow at f/2.0 or f/2.8 with close-ish subjects that any movement on my part can put the subject beyond the range of acceptable sharpness. My breathing can do this in some cases. Poor shooting technique will show up in a hurry with this lens. That got evident the first time I used it.
    • If I've got a really shallow DoF setup going on, the subject can easily move out of the range of acceptable sharpness. It doesn't take much - in some situations, the slightest subject movement toward or away from the camera can cause problems with sharpness.
    • Using a really high ISO - the D7000's high-ISO noise reduction can 'smear' the image a little causing loss of fine detail or texture, making it look soft. Use the lowest ISO possible for best overall sharpness.
    • Back or front focusing - test focus by shooting a proper focus target (commercial or home-made - here's a decent free one) from a tripod and see if it's OK. If it's front focusing or back focusing a little, see if you can tweak the auto-focus in the camera (p.246 of the D7000 manual). Tribal knowledge: from what I hear from other 135/2 DC owners, some digital cameras' AF fine-tune will not correct back or front focusing with this lens. Mine didn't need any correction with my D700 - have to check it out with the new D7k. It appears to be a problem with some of the lens units, not the cameras. If you rule out all other causes of unsharpness, and it can't be corrected with in-camera fine-tuning, send the lens back for exchange.
    Even at f/2.0, this lens should be able to produce more than adequate sharpness in the central portion of the image. The DX format should crop off the worst of any corner unsharpness caused by shooting with a wide open aperture. Shooter unsteadiness, slow shutter speeds, or subject movement seem to cause the most unsharpness problems with this lens. That's my 2ยข. HTH.
     
  13. Thank you all for such amazing responses and suggestions. I have tried a few additonal test shots and am noticing quite a bit of purple and green fringing at high contrast areas. Much more than I see on any of my other lenses. Is this something I should expect as well?
     
  14. Two things, one, D.B, the FBI is looking for you, and two, everything D.B said.
    I own this lens, and it is one of the better portrait lenses (IMHO), unless you are not comfortable with a 135mm portrait lens, or feel the need for 1:1.4.
    I would search you tube and watch all the videos. Surely there are videos on this lens.
    Yard stick? I prefer a new 1 1/2" wide bright yellow tape-measure with 1/16 increments plainly marked on one side and 1/32 on the other. On a tripod, hook the tape-measure a foot below the camera, and the other end of the tape-measure out away from the camera level with the ground. Focus at a spot 3 feet out on the tape-measure.
     
  15. Todd, CA can certainly be an issue with this lens at the wider apertures. It's the same as the 85mm f/1.4 D or most other fast primes for that matter. I don't know how much worse this lens performs than others but the professional reviews actual say that this lens handles it better than most. I'm not a lens tester so I can't say for sure. I know for sure that it can be an issue with the 35mm f/1.8, the 50mm f/1.4 G, and even the 10.5mm fisheye. I don't find it to be much of an issue since it's so easily corrected in post.
     
  16. Todd,

    I mentioned the LoCA, (purple and green fringing), in my second post. It is reportedly worse with the 135mm than the 105mm, but it can be fixed with a few different methods. The LoCA is also generally much worst if your subject is backlit.
    I don't pixel peep and can generally minimize the CA with lighting. If there's any question about how bad I think it's going to be, I switch to my 70-200mm and shoot at 105mm to get a similar effect, albeit with less flattering bokeh.
    Also, make sure you are not using a protection/UV filter with this lens as it seems to magnify the CA on my lens.

    RS
     
  17. Do your sharpness tests at f8-11. Unless your subject is pretty far off, f2 and f2.8 are going to be near paper-thin.
     
  18. every picture from big matrix could look soft at 100% screen enlargment - no matter what the lens is.
    the effect vanish when you'll make print in desired size. remember, that big matrix require more sharpness in post.
    if you try this lens on 6MPix or even 12 you'll see it sharper:) (but only at the screen)
     
  19. I've had this lens for 2 months and immediately loved it. My copy was exactly on focus on my D700. At F2 the depth of field is very narrow but bitingly sharp to the point of needing care with portraits- those pores and hairs can be surprising. I don't use the defocus control on this or my 105f2. Mainly I got it for dark high school gyms. More and more I keep it with me.
    I hope you get yours tuned. The AF fine tune is the first place to check if the defocus control is on zero. My 105 DC needed a major adjustment to get it on focus. Best wishes.
     
  20. Just to say thanks for the discussion above... I just got my first roll back, after shooting following the guidance above, and am happily blown away. For full AF (moving kid), I just kept the DC at or below the aperture; for still I cranked up the DC and manually focused it...the busy background turned to creamy oblivion. Also put it on a dSLR for indoor shots, and AF worked just fine...again sticking to the 'at or below' rule.
    Just a beautiful lens. (Caused me to put my 105 AI-s up for sale!) Great discussion, much appreciated.
     

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