Is Nano Crystal Coat At Fault Here?

Discussion in 'Nikon' started by dan_meyers|1, Jan 31, 2010.

  1. The issue is with my new AF-S 24-70mm coupled to my D700 shooting under Lowel Tota-lights. Each time I use this particular combination I get RAW files that show a pinkish-yellow color tint. If I change lenses and use either my 85mm PC, 35mm f/2, or 50mm 1.8 under the same lights there's no color tint issue at all! Whites are white.
    Camera is set to Auto WB, I've tried different CF cards and nothing helps. Is it possible the coating on the 24-70mm is adversely interacting with the quartz lights? Under my strobes and outdoor daylight the zoom is dead-on.
    I called Nikon in Melville and they basically told me to stop drinking and take a warm shower, but it's a consistent problem. Anyone have an idea what's going on here?
    Thanks.
     
  2. you're drinking too much and you need a shower. um, i don't know. maybe post a pic?
     
  3. Of the four lenses that you listed, they probably all have different formulas of glass, and possibly, even plastic. Different batches/generations of coatings will also throw a curve to the mix.
    It is more likely a quirk with your lighting source and it's transmission, which shows up more prevalent in your 24-70. I've always gotten more intelligent answers from Nikon's parts guy compared to anyone at Melville, and it never hurts too much to take a shower ;->
     
  4. Eric,
    I've toweled off and put down the bottle. Hopefully the images are showing.
    00VefX-216211584.jpg
     
  5. other one
    00Vefh-216211784.jpg
     
  6. Just to be clear, these are jpegs of the original RAW files and that wall should be white.
     
  7. I bet the camera is influenced by the light source "in" the image shot by 24-70 and adjust the WB accordingly, or is fooled by that. If you want to nail the cause of the difference of the hue, you would need to compare the lenses with the same contents within the image frames.
     
  8. "Camera is set to Auto WB..."​
    There's your culprit. Auto white balance is always a compromise. It works okay with some cameras for some lighting, not so well with others. Save auto WB for expediency.
    Set a custom WB for the lights. Yes, different lenses may impart slightly different effects on white balance so it just makes good sense to custom WB through the lens whenever changing the lights or the lenses or both. My older Vivitar Series 1 70-210/2.8-4 zoom will have a slightly cooler result with WB than my 105/2.5 AI Nikkor, so when I need critical accuracy I use the custom WB through the lens.
    The rest is down to getting acquainted with the basics in digital editing and working with raw files.
    "I called Nikon in Melville and they basically told me to stop drinking and take a warm shower..."​
    That' seems like a bit of hyperbole. What did they really advise?
     
  9. Lex,
    Honestly, I'm expecting better RAW performance with a D700 and the 24-70. I'm fine with post-processing and all, but this is more than just a tweak on manual WB and the difference seems inappropriate for such a kit.
    Melville said I should return the lens to B&H to get a new one.
     
  10. Just shoot a custom WB pre-set it only takes about 5 seconds to do that and the WB will be nailed from then on while shooting in that light with that lens. You don't need to send that lens back to nikon or get a new one. Just set your WB correctly and you will be fine. And if you can't be troubled to do that then just shoot raw and fix it later in post. I hate doing that because it takes too much time and is not the right way to go.
    I remember way back when I first started in photography I wrote in complaining about the same thing saying my camera was broke and one of the sages on here told me to learn how to use the camera because there was nothing wrong with it. He was right...
     
  11. Auto White Balance is rarely 100 percent accurate regardless of which camera you use and especially in artificial lighting. As Keith suggests, Custom White Balance will solve this problem. Consider purchasing an Expodisc, for example.
    Also, if that wall is supposed to be white, you have underexposed the shot. Are you using an incident meter?
     
  12. I agree with those who are recommending presetting the white balance. Auto anything on a Nikon body does a pretty good job, but my experience is that sometimes it is far from perfect, especially white balance. That's why they have the white balance preset feature. You're in the studio using consistent or controlled lighting, so it only makes sense to use it. I doubt there is a problem with the lens. You might want to try it with a film camera, transparency film and different lenses just to see what happens.
     
  13. maybe it is the nano coat, maybe that lens just has a distinct optical 'signature,' but changing WB settings would be where i'd start, too. if you've already tried it with different lenses, that narrows the possibilities. do you also get the yellow tint outdoors with no lights on AWB?
     
  14. Dan, I've studied the EXIF data for your two sample photos and don't see any inconsistencies that might be explained by anything other than the auto white balance and different lenses. I'm assuming you used exactly the same setup with the Tota lights for both shots - with the lights bounced off a light colored wall (which, incidentally, is probably not perfectly neutral white).
    However, in reviewing dpreview's 2008 review of the D700, just now, I see this comment:
    Their sample image with auto WB under incandescent light is very warm, comparable to your results with the 24-70/2.8 AFS.
    And I absolutely agree with their comment regarding P&S cameras generally having better auto WB performance. Any of my Olympus P&S digicams, all several years old now, consistently deliver better auto WB results than my D2H under the same artificial lighting conditions, whether incandescent, fluorescent or the very difficult metal halide lights found in some gyms, auditoriums and industrial settings. The one peculiar exception is the D2H on auto WB with the SB-800, no gels or filters - it consistently produces very good results under most artificial lighting, which saves me a lot of time in processing since JPEGs are usually good to go. And the D2H excels in daylight. But AWB by itself with any other artificial light, it's a crap shoot... mostly crap.
    Under the circumstances, if you are otherwise satisfied with the 24-70 you might be better off keeping it and setting a custom white balance. If the lens has acceptable performance, edge to edge and corner to corner, is acceptably sharp wide open and has no other flaws, you might be trading one problem for another by swapping for another copy of the same model. But if you find any other flaws with your existing copy of the lens, well... it's a very expensive lens and you might as well take advantage of this opportunity to accept Nikon's offer.
     
  15. Thanks, everyone, for your suggestions; I'll work with the manual WB. Except for the weight and cost, everything else about the lens is great and I definitely don't want the hassle of returning it and taking my chances on getting a real problem in return.
    Maybe I was just under the Nikon marketing spell all along!
     
  16. Nikon DSLRs have traditionally had mediocre Auto white balance performance at lower Kelvin values. Do you have the latest firmware, version 1.02, installed? It's quite an improvement over previous versions, in terms of Auto white balance at lower Kelvin values such as the tungsten lighting you're using.
    As others have said, with any subject matter that's important, and if you're working fairly deliberately, why not shoot a manual white balance with a neutral target?
    How is the color response of your 24-70AFS when you manual white balance, both in tungsten and daylight Kelvin values? Lastly, are you getting a good auto white balance in daylight Kelvin from this lens?
     
  17. > "If the lens has acceptable performance, edge to edge and corner to corner, is acceptably sharp wide open and has no other flaws, you might be trading one problem for another by swapping for another copy of the same model."
    Do other people really see as much "sample variation" among nikon lenses? I have been been buying Nikon lenses since 1981 and I have never returned one, although I have certainly sold a few.
     
  18. Dan Meyers , Jan 31, 2010; 08:53 p.m.

    ................."Camera is set to Auto WB............"​
    And therein lies your problem. I wish Nikon had left off Auto WB off completely as it is wrong more than it is right. Your surest bet is use a gray card and find out the color temperature of the light and use that.
     
  19. Is the tint the same with in-camera jpegs (or with NEFs processed using ViewNX / Capture NX rather than ACR)?
     
  20. If color accuracy is critical to the job at hand then a custom WB is required.
    If you are processing in Lightroom or Aperture then there is always the option of selecting "incandecent" WB and bypassing the Auto setting. Also these programs will only approximate the auto WB setting that the camera has embedded. Lightroom is the worst at this. I always select "Camera Standard" in LR when importing files to bypass the auto WB setting imposed by Lightroom.
    If you do decide to use a reference card, I suggest using grey instead of white for the balance. I use the WiBal cards and they work well. Also it's important that the camera is set as close to base ISO as possible for the best color accuracy.
    My experience with the Nano coated lenses are that they generally have a nicer look than others in the Nikon range.
     
  21. Eric -- under my strobes and outdoor daylight the images look terrific.
    Brooks -- yes, I've got the latest firmware.
    Richard -- interesting, but I don't shoot jpegs. I'm going to try it for the sake of learning about this issue but it seems rather clear by this point that a custom WB is the way to go.
     
  22. Do other people really see as much "sample variation" among nikon lenses? I have been been buying Nikon lenses since 1981 and I have never returned one, although I have certainly sold a few.
    Rob, that is a very interesting question that warrants a whole new thread. Most of us wouldn't know the answer because we don't get two copies of a lens at the same time to compare. I'd be very interested in hearing from people who do have experience with this. Please start a new line of discussion if you haven't already--I'm going to go check to see if you have...
     
  23. For artificial lighting, the best performance in WB is to do a custom WB capture using PRE option with a piece of white paper. It will solve most of your WB headaches.
     
  24. I've definitely experienced variable WB from the D700 with the same light source, from shot to shot. Actually, you get some really cool results by shooting a Fluorescent tube-light at continuous-high for a couple of seconds.. you get 10 shots, each with a vividly different colour cast - lots of fun!
     
  25. Dan, the recently released firmware update is supposed to improve WB performance. Have you updated your camera's firmware yet?
     
  26. Of course there is always the "old fashioned forgotten method" of using a light meter that is capable to measure color temperature. Since such meters are "absolutely unnecessary today" one can sometimes get these meters cheap on ebay.
    It is often "OK" to adjust WB manually in PP but why not start with the correct settings while taking the image?
    You would also be able to use a color correction filter to optimize image recording for the given light. It helps to fully use the dynamic range of the camera. There is a large number of excellent threads in dpreview. If you google on wb, filter, color correction and such you will be able to follow.
     

Share This Page