AF Nikkor 180mm f/2.8 ED

Discussion in '35mm Cameras' started by Paul Furman, Feb 17, 2010.

  1. Paul Furman

    Paul Furman Guest

    Discontinued lens, bought used for $400. Sharp as heck, though I did
    have to tweak the CA corrections pretty heavily and it's still got a
    blue fringe thing:
    -6MB original full size, 1/250 sec, f/8, ISO 200, D700's tests show less CA though the scene above is a
    challenging one and theirs is DX:
    Note the sharpness is almost the same wide open corner to corner.

    Bjorn R. gives it almost top rating:

    Very nice bokeh & closeup performance too:

    In the interest of nitpicking, here's a horrible looking, worst case
    example of the CA at 300% enlargement, in the very corner, with
    lightroom defaults compared to corrected final:

    It never ceases to amaze me how complicated tradeoffs are for lens
    design. I haven't tried comparison shots against the 70-200 VR I but I'm
    thinking this is a replacement for that. It works well with PN-11
    extension for butterfly & flower closeups but you can't push that too
    far on a bellows.
    Paul Furman, Feb 17, 2010
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  2. Paul Furman

    Henry Olson Guest

    Tell that to all the P&S super-zoom camera designers who have come very
    close to doing just that at apertures as wide as f/2.0 without any easy to
    fracture, easy to permanently fog, fluorite elements.

    You fool troll.
    Henry Olson, Feb 18, 2010
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  3. Refutation by counterexamples and both are even 180mm lenses:

    Please feel free to acquire and test both.

    Here's a follow-up homework assignment for you. Compare and contrast
    the optical and physical properties of fluorite crystals with Ohara's

    My guess is that Paul's lens may be suffering from a slightly decentered
    element. I have the current "D" model 180mm f/2.8, and optically I have
    no complaints. It's not truly APO, but the small amount of CA that is
    present is easily correctable.
    Michael Benveniste, Feb 18, 2010
  4. Paul Furman

    Paul Furman Guest

    Yow, there's a used buy-it-now 2.8 on ebay for $3k. The Nikkor was/is
    about $1k new. I paid $400.

    Possibly, it shows more CA than I expected. If so I should be able to
    see asymmetrical fringing under the right test conditions... the CA
    corrections should work asymmetrically. I've never noticed a lens where
    the yellow/blue CA slider played a significant role like this, though I
    don't generally fuss about those corrections for every shot. It's hard
    to even see in a normal scene.

    Ah, OK I didn't know there was a difference.
    Mine doesn't have the D on the label, just ED
    "The current AF-D version encodes and transmits distance information to
    the camera for added exposure accuracy, especially with flash."

    The scene I showed is about as challenging as it gets with backlit twigs
    right up into the corners. Full frame digital makes CA a little worse
    than on film.

    One disappointment is it doesn't work with my 1.4 AF-S teleconverter. I
    can however put a short extension ring between and get impressive
    closeup possibilities. That gives a 6-inch wide FOV about 30 inches away
    to 12-inch wide about 10 feet away. Pretty nice for chasing butterflies
    & hummingbirds. With 50mm of extension and no converter I get about 8"
    wide at 10' to 4" at 30", roughly.

    I originally used the 70-200 VR with a closeup lens on the front but
    that does some weird bokeh & internal reflection stuff, though the VR is
    nice, the results are pretty mushy for closeups. I'll have to try the
    180 with TC & short tube in the field.
    Paul Furman, Feb 18, 2010
  5. Paul Furman

    Paul Furman Guest

    Hmm, that worked nicely. I didn't know there was a decent way to remove
    axial CA - as in fig 3 here:
    Or am I misunderstanding? The full jpeg alread has transverse CA
    corrected (the normal correctable type).

    I just did a test against the 70-200 VR with a symmetrical view of
    venetian blinds to test sharpness & CA at 20' distance. As I was
    guessing, the 180 is sharper but much worse CA. And the 180 has equal
    performance wide open or at f/8, for sharpness and CA. I did a couple
    re-focuses manually for each and re-did the 70-200 with the proper
    tripod mount. First test with the lens dangling suffered from shutter shake.

    The 70-200 VR-I had virtually no CA to correct.

    The 180 *did* in fact respond to asymmetrical CA corrections.
    Blue/Yellow in the upper-left was better at -43 vs +7 in lower-right at
    2.8, for the f/8 shot -40 vs -7. Hard to judge with only horizontal lines.

    So yeah, some de-centering. Does that mean the overall CA is worse than
    it should be? Could it be corrected if I sent it back to Nikon? It's
    still sharper than the 70-200 though.

    Here's the tests, uncorrected if curious:
    Paul Furman, Feb 19, 2010
  6. I think our lenses have the identical optical formula, and the "D"
    information shouldn't make any difference for CA. However, your lens
    is at least 15 years old, and until recently 180mm primes tended to
    see heavy professional use. That's why I wouldn't be surprised if
    something got knocked a bit askew over the years.
    I don't have a full-frame digital camera yet, so that might be a
    difference as well.
    I've used mine a couple of times with a Kenko 1.4x DG teleconverter
    with acceptable results, but the one time I tried a direct comparison
    with a 300mm f/4 my (lack of) long lens technique wasn't up to the
    Michael Benveniste, Feb 19, 2010
  7. Leica claims both lenses are apochromatic. You'll just have to buy
    and test both for your assertion to hold.
    A bare assertion means a failed assignment. Present your results.

    Here is a test on a 4" S-FPL53/S-BSM81 _doublet_ which shows that
    it is apochromatic by the Abbe/Zeiss definition. 2 Matrix.jpg
    Whether it can _take_ a polish is one thing, but whether it can
    _hold_ the polish is a more interesting question. Alkor, a
    manufacturer of CaF2 lenses, only claims the polish can withstand
    "several years" of exposure to normal atmospheric conditions. CaF2 is
    also softer and has a higher thermal expansion coefficient than
    S-FPL53. But cracking due to thermal effects? Not hardly.
    Michael Benveniste, Feb 19, 2010
  8. Paul Furman

    Paul Furman Guest

    Interesting. Here's another example of probably a classic double gauss
    or similar:
    -quick google for me to get some kind of clue...

    Apochromatic doesn't mean perfect, Sigma has loads of APO lenses <g>,
    most probably quite good. As I understand, it means more than just a
    couple basic colors are corrected for. They might not even be well
    corrected but an APO has at least tried to correct some other colors. I
    never saw that term used for the 180, actually it looks like achromatic,
    extremely well corrected for red/cyan, thus all the CA shows in
    blue/yellow, which is really odd. What is more surprising is it doesn't
    seem to change from f/2.8 to f/8, nor does sharpness or center to corner
    performance. I only have one APO, that's a Voightlander 90mm f/3.5 for
    Leica screwmount, bought for closeups but because of the flange mount
    difference it's only usable right around 0.5x. That one also is just as
    sharp wide open and also has some weird CA, with a blue/orange cast, and
    can show purple fringing in extreme contrast.
    example (crop):
    full frame:
    The blue fringed dew drops remind me of the blue shadows of twigs in the
    OP after correcting blue/yellow CA.

    Anyways, you can show flaws in any lens shooting diamonds at macro
    distance directly against the sun or whatever quirk. I also like that
    the lens is quite compact with built in lens hood and built like a tank.
    It was very clean apart from a couple nasty dust flecks inside but I
    couldn't get them to show even in a big bright OOF circle. Then I got it
    home & soon dropped the damn thing attached to a heavy bellows rig. The
    edge of the filter ring got dinged but the filter threads still work
    perfectly. Built like a tank. I'll count the aberrations as character &
    remember to apply corrections <g>.
    Paul Furman, Feb 19, 2010
  9. Paul Furman

    Peter Guest

    Try a 12mm extension on the 80-400. I've gotten some pretty decent results.
    Peter, Feb 20, 2010
  10. Paul Furman

    Paul Furman Guest

    Still, that's not exactly 'purple fringing' as I'm seeing with this.
    It's blue & doesn't change to green with front/back-ness like axial CA.
    Alright, yes it is, after doing a specific test for that:
    That's compared with the 90mm APO-Lanthar I mentioned, which shows much
    less of the effect but shows the same distinctive robin's-egg blue
    fringes on objects in focus or in front of the focal plane. A softer
    green behind. Most lenses that show axial CA do more of a purple.

    I did a bunch of closeups Friday with & without teleconverter &
    extension tube. After correcting for the lateral shift CA, there are
    still deep robin's-egg blue fringes around white flower petals on the
    darker background:
    and in the OP, the blue shows in the shadows of the narrow back-lit

    Here's Purple Fringing with the APO-Lanthar:
    -I need to reload their pages, then scroll to the bottom

    I still haven't heard a perfect explanation for that kind of purple
    fringing. That's purple, not blue like I'm seeing.
    Paul Furman, Feb 21, 2010
  11. Paul Furman

    Paul Furman Guest

    The flowers are reduced & flickr sharpens automatically, the other pair
    of tests had some CA correction but it doesn't make much difference.

    Perhaps the axial CA is a bit more purple further into the foreground
    but where it's in focus, the fringe is blue.

    Yep. Complex and weird stuff. I've not been able to produce that kind of
    purple fringing with the APO-Lanthar, just a tiny bit of blue fringing.

    Anyways, the APO-Lanthar and the 18 Nikkor are both sharp wide open,
    very well corrected and both show the blue fringing. The Nikkor has the
    unique character that the CA & fringing does not go away until f/11,
    according to a discussion on The blue fringes do give an
    interesting character to the results; blue is not as offensive as
    purple. The purple just looks freaky, blue looks like sky-tinted shadows
    in the example of twigs, not as nice for the edge of white flowers but
    better than purple I guess.

    Here's the best page on sensor blooming & demosaicing as an explanation
    that I could find (although it's an oldish 'draft'):

    "Big Fat Disclaimers

    Marginal advice is without warranty, and Camp Ratty makes no claims of

    This marginal advice is offered along with some irreverent back alley
    tutorials, based on one user's experiences. These opinions do not
    reflect those of the management. There is no management.

    These notes were just fun, and if they require any real work, it's
    gonna be time to rethink the whole damn deal.

    Copyright 1998 Camp Ratty"
    Paul Furman, Feb 21, 2010
  12. Paul Furman

    Paul Furman Guest

    No problem. I uploaded some raw files, unfortunately you may not be able
    to use those properly or at all with Capture NX2?
    OK I added a couple NEFs also, which happen to show more of a magenta
    fringe than the others.

    It's a wicker chair at closest focus with a (partly?) cloudy sky through
    the window but yeah the camera's auto white balance did give it a
    blue/cyan tint if I crank down the exposure.

    I really don't see magenta as much as blue. If I make the sky neutral,
    it gets magenta on one side, blue on the other & the red/cyan CA slider
    can make them both blue at +19. There is a very small unfringed area
    just behind the plane of focus.

    If I make the petals neutral, the fringes are still blue. They only go
    magenta with an extreme WB.

    Just a faint but wide magenta glow around the white flag pole on the bow.
    Paul Furman, Feb 22, 2010
  13. Paul Furman

    Paul Furman Guest
    Give those 10 minutes to finish uploading.
    Paul Furman, Feb 22, 2010
  14. Paul Furman

    Paul Furman Guest

    I don't think my D700 has that feature, maybe in the jpegs? Could I see
    what NX does? See if I can match it with Lightroom... You could email a
    full jpeg if you don't mind. Lightroom has 'defringe'
    which doesn't do anything I can see.
    Paul Furman, Feb 22, 2010
  15. Paul Furman

    Paul Furman Guest

    Paul Furman, Feb 23, 2010
  16. Paul Furman

    Paul Furman Guest

    ....not to put too fine a point on it but...

    So, I downloaded a trial version of Capture NX2 and it does work nicely
    for this. There is still a cyan fringe but much better.
    -that's just working off the jpeg, I never saved NEFs, out of spite for
    Note how the top LR examples alias/moire the purple into alternating
    bands of red & blue where NX gives a smooth edge. NX does leave red in
    the fringing, it only takes out the blues. It doesn't touch the yellow
    green axial fringing in the background but that's less objectionable to
    start with.
    Paul Furman, Feb 24, 2010
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