Mac Loc: Pittsburgh, Philadelphia now Hernando Co. Fl.

Thank you for demonstrating and for the suggestions Rick

Mac Loc: Pittsburgh, Philadelphia now Hernando Co. Fl.

Thank you Bill, I will look at the YouTube.

aflundi Loc: Albuquerque, NM

Really? Floyd, I thought the point of the defocus control was to control the over/under correction for spherical aberration. That if set positive, it would yield smooth background boken, smooth foreground bokeh when set negative, and neutral bokeh when the DC is set at 0 with perhaps a little sharper in-plane focus.

I don't have one, so I haven't had a chance to play first hand, but I thought I had read enough Nikon papers to have fooled myself into thinking I understood it.

Apaflo Loc: Anchorage, Alaska

It does in fact control correction for spherical aberration, and one effect is essentially what you describe. But moving the DOF is the most significant and most visible change, and is what the adjustment ring is calibrated to match.

For example if it is set to affect the background and focused at 15 feet, you get about 21 inches of DOF at f/8. If the intent is to have a subject's face sharp and everything from the ears back increasingly out of focus it is possible to focus about 5 inches in front of the subject. That required accurate measurements and a DOF table. Twenty-five years ago, using film, a mistake was a disaster. But with the DC lens the focus can be on the eyes and the DC control might be set to f/8 or f/11 (for less out of focus ears). It would be easy and accurate every time. Today with immediate preview we can sort of blindly move the focus out in front and just snap a shot to see the effect.

By the same token people often expect setting the DC control to f/4 or even f/2 should cause even smoother bokeh, and instead they get a very blurry image. When the actual aperture is the same value as the DC setting the edge of the DOF is just past the plane of focus. Of course knowing exactly how that works can be used for odd effects...

Rick36203 Loc: Northeast Alabama

Defocus control on the 135 is only available at full stop aperture values between f/2 and f/5.6.

Apaflo Loc: Anchorage, Alaska

Okay. I haven't used mine in 2 or 3 years. Actually though I'm pretty sure that while marked to only 5.6 it has another click stop for f/8. I don't remember now if it goes past that.

But the specifics were not the point. There really isn't much reason to move the DC adjustment off center when shooting digital. The intent was to convey what it does and how it does it.

Rick36203 Loc: Northeast Alabama

You're right. It will continue a little past the last mark (f/5.6) each way and lock in position. I guess that may or may not be f/8. But again, as I am personally unable to detect any significant (or even subtle) difference when using and not using defocus control, I choose to leave mine in the off position at all times.

Apaflo Loc: Anchorage, Alaska

Set the aperture to f/4 and the DC to f/2. That should have visible results.

Otherwise, take a picture of a tape measure angled to let you see the DOF. Then all the variations will visible.

rfmaude41 Loc: Lancaster, Texas (DFW area)

I have shot both of the DC lenses, currently own a 105mm DC. It's one of the sharpest lenses that I have; use it for cropped and film cameras.

aflundi Loc: Albuquerque, NM

I can't say I followed your explanation. Are you saying that the plane of focus actually shifts away from the PDAF point toward one DoF bound or the other at the same time and in addition to the SA corrections? And that the DC lens has DoF builtin, and therefore an assumed CoC -- presumably for FF -- in order to know where the DoF bounds are?

[ It looks to me like the 135/2DC only has DC adjustments between -f/5.6 to +f/5.6, and that is an example of one of the things that I find confusing about your explanation. I also don't see how the lens tells you 21" DoF at 15', and a setting of f/8 will adjust back 5". I assume your examples were just conceptual rather than exact and concrete, but I'm afraid it none-the-less confuses my tiny brain. ]

Robeng Loc: California

MAC,

This is not your ordinary 135mm telephoto lens. I have used this lens and love it but it's a specialty lens designed for portrait use. Until recently this lens was probably Nikon's best portrait lens until the newly released 105mm f/1.4.

Most photographers have no idea what the Defocusing Control is for. Nikon made this lens specifically for portraits. So they developed the ability to control boken in front off and behind the subject, that's the DC control on the front of the lens. AF is auto focusing. This is an old style lens made out of metal not plastic.

Open Box means that a salesperson open the box and showed it to customers. The warranty is still valid and applies to this lens. B&H has great customer service so if you don't like it after a week send it back for a refund.

Rob

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

Good opportunity to take it off the shelf, brush the dust off, take some pics and post some examples for all of us to see, Floyd. Just like the others that own and use these lenses. Of course, you can only do that if you actually have one. . .

Apaflo Loc: Anchorage, Alaska

If you actually had one you could verify in an instant, as I have, that my memory was correct. It has marks to f/5.6, it has detents to f/8, and the ring can be moved to the stops which is in fact the f/11 setting. Another small factor you are not aware of is that Nikon says that is true, and that they originally intended to put marks all the way to f/11, but decided not to. At f/11 it is not equally effective, but they do recommend experimenting with it.

http://nikkor.com/story/0032/

And in fact you also totally missed the mistake I did make. I said set the aperture to f/4 and DC to f/2 to see blur at the focus plane. WRONG! Set the DC to f/8 or f/11.

Some day you will learn to discuss technical topics, and leave these silly fabricated gratuitous personal insults/comments out of it...

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

Don't have one. Great lens. Don't know anything about it other than what I have read - and it does make sense. I didn't miss a thing, as I don't claim to know anything about it, but you apparently did by your own admission. But the question is do you have one or are you just reading the same things I am and proclaiming, once again, to be the expert on something you have no experience with . . . Just sayin'

(I am in the mood to poke at you today, nothing personal, just having some fun)


Anyway, stop deflecting and show us some images - I am sure if you have one, you've taken a few, just like the real photographers that posted some really nice work. You are a real photographer, aren't you?

NikonCharlie Loc: Kansas USA

I own it, used to use it for portraits. Not used it for a good while now, but it's a well made, heavy lens with a built in hood.
AF-D lens will not auto focus on many newer Nikon's (such as D3XXX and 5XXX cameras and others), you did not mention your camera.