Nikkor 105 DC auto focus issues?

I don't know if it is an error on my side or the lens. I acquired a Nikkor 105 DC and it looks as it has a

problem with auto focus. Here is a link to some test images:

 

http://www.avianart.com/105dc/web/content/index.html

 

The first image is with auto focus. The second with manual focus. The Defocus control was set to neutral/

off. Is this the way how it is supposed to be? Or does this lens need a CLA?

 

Any help is greatly appreciated.

 

Thanks,

 

Rudy

What results were you expecting to get? [105mm + 52.5mm = 157.5mm on a digital Nikon body.] At f2 the results seem to be acceptable. The lens was designed for a film body and using f2 as a 'test' seems to be needed to try f5.6 or so. With defocus at (rear) f2.8 and the lens set at f2.8, your background should be de-focused fairly well.

Gerald,

 

I am sorry, I guess I have not properly explained what I meant. The second image is sharper

than the first one. e.g. with manual focus the image is sharper than with auto focus.

 

Thanks,

 

Rudy

Rudy

Try the test again with a flat subject. A page from the news paper taped on a wall works well.

With a face it is easy for the shot to be focused on a different part of the face.

Also try to keep the exposures the same.

 

I dont have a 105 DC I do have the 135 DC. With my lens to get sharp shots I keep my Defocus control set to f/2 front. There is a noticable difference.

 

Michael

Did you aim the AF sensor on a particular area, such as the eye, and then recompose as necessary for framing?

 

When shooting wide open with any fast lens I find it necessary to use this technique with any autofocus camera: place the AF sensor on the desired area, lock focus, then recompose. Even with the D2H (and D2X), which have 11 AF sensors to choose from, I often need to recompose after locking focus if I want, for example, a person's leading eye to be in sharpest focus.

 

However, I have no doubt that manual focus is often superior to AF for critical focus when using a fast lens wide open. AF is a convenience for use when speed is the primary factor and accuracy a secondary consideration.

I know what you mean, Ruediger.

Ironically, I bought this lens for its AF feature, as I had (and still have) the 105 mm 1.8 AiS.

 

http://www.flickr.com/photo_zoom.gne?id=810824644&size=l

 

It has to do with incorrect mounting of the rotating DC element.

I returned it to Nikon, and it came back with only a small improvement, but with a lot of dust inside.

 

Tip 1: I can get a small improvement with systematically setting the DC ring on 2 Front (before the "fix" I needed 2.8 Front). You should do some tests; but in order to be sure, I go manual (as you figured out yourself).

 

 

Tip2: It seems that you can correct focussing issues with the D3 ;-)

Note that the DX format is more sensitive to focusing errors than FX or 35mm film. This is because given an aperture (f/2), focal length (105mm) and a fixed distance to subject, you have less DOF on DX than FX/35mm. Thus the autofocus cam needs to be controlled more precisely to get the result within the DOF.

 

I have been extremely happy with this lens on 35mm film. At f/2 on BW400CN you can get beautiful available light indoor pics. On DX (D200) I need to stop it down to f/3.5 or so to get good sharpness. At f/5.6 it produces the highest quality images of any lens I have.

 

I'm not sure if anything can be done. I tried adjusting the DC and that didn't really help with the consistency of focusing. I primarily use this lens either stopped down on DX or at any aperture on 35mm film. If you need a fast short tele for DX, I suppose the 85/1.4 is a better choice if you're autofocusing.

 

Or, you can just use it as a manual focus lens (but on the D80 you do get metering also, which the 105/1.8 doesn't give at least not without a chip).

Stef's on the right track here. I had this lens, purchased used, and *could not* get reliable

autofocus results from it no matter what body I chose -- D70, two different D200 bodies --

none of them would snap focus on the correct area. Manual focus was the only reliable way

to get a sharp focus point. When I returned the lens for a refund, the seller thought I was

crazy, or at least the autofocus problems were my fault. After they sold the lens a second

time -- and it was returned for the same issue -- did they realize it had mechanical

problems.

Guys, thank you very much for all your answers.

<p>

Michael, I tested it on a test chart. And I found out that with DC Front 2 the lens is

reasonable sharp. Though not as sharp as the 105 2.8.

<p>

Lex, I aimed the auto focus with the middle sensor on the left eye. And I did manual focus

at the same spot.

<p>

For me the question was, should I return it or should send it to Nikon. I have a Katz Eye

installed on my D2x. In this way I saw right away that there seams to be something

wrong with the lens. Non of my other lenses (50 1.4,17-55,70-200,200-400 etc)has this

behavior, they all focus accurately. On the other hand this is a special lens, which

obviously needs special attention. I knew that. I just did not expect this focus issue.

Anyways, I will use it in manual focus, which is just fine. After all I like the soft images this

lens can produce. This is not just a portrait lens, you can create dreamy photos like

Hamilton. I did some more tests on a test chart, nothing scientific, but interesting

nonetheless. Here is the link

<p><p>

 

<a href="http://www.avianart.com/105dc/web2/">105 DC test images</a>

<p>

And here is a list with some info to each image:

<p>

1 105 DC @ f2 Neutral<br>

2 105 DC @ f2 Front 2<br>

3 105 DC @ f2 Front 2.8<br>

4 105 DC @ f2 Front 4<br>

5 105 DC @ f2 Front 5.6<br>

6 105 DC @ f2 Rear 2<br>

7 105 DC @ f2 Rear 2.8<br>

8 105 DC @ f2 Rear 4<br>

9 105 DC @ f2 Rear 5.6<br>

10 105 DC @ f2 Front 2<br>

11 105 DC @ f2.8 Front 2.8<br>

12 105 DC @ f4 Front 4<br>

13 105 DC @ f5.6 Front 5.6<br>

14 105 DC @ f2 Rear 2<br>

15 105 DC @ f2.8 Rear 2.8<br>

16 105 DC @ f4 Rear 4<br>

17 105 DC @ f5.6 Rear 5.6<br>

<p>

 

 

Again thanks for you inside and happy shooting.<br>

<br>

Rudy<p>

 

P.S. Did someone recognize the guy in the first photos? ;)

I think it's not a problem with the lens, but the cameras. I have similar issues with my D200 but none whatsoever with fine grain 35mm film on an F100. The autofocus systems of the DX cameras are unable to effectively use this lens at wide apertures - I would blame it on the design of the autofocus of the camera. I don't see what could be repaired in the lens. The autofocus of a screwdriver lens is primarily a camera feature, and no amount of adjustment to the lens is going to help. Anyway, just my opinion.

Hi,

 

I have one of these, and I, too, am seeing images that make me unhappy. But, what I see in my images and in yours is a tendency to focus in front of the intended point. In your original series, the lips are sharper than the eyes. The lens seems to be front focusing.

Ilkka, I still have an F100. I perhaps will try it. Thanks for your thoughts.

 

David, I agree it seams to front focusing.

 

Rudy

My 135mm DC is in Melville even as we speak being calibrated-- send it in..

Marke, how much is such a calibration?

Well, this is a most useful thread. I commented earlier on my 105 DC tending to front focus, and I tried out the suggestion to set it to F 2. Wow! What a difference that made. Now I'm a very happy camper.

 

I've posted a pic (I hope, as I've haven't done that before) that shows a series of shots from -20mm to +20mm in 5mm steps around my AF focus point, 0mm. That is, I AF, turn the camera to MF, and move it back and forth with a macro rail.

 

Top row is my 85mm f/1.8 at f/2, next is the 105 DC, no adjustment, and the last is the 105 set with F2. What I'm looking for is centering at 0mm, consistent with best focus being at the AF point.

 

Couple of observations. First, the F2 adjustment did the job, and it is now as sharp at 0mm as it was before at 5mm-10mm. Hurray! Second, it is sharper than my 85 f/1.8 at f/2, which is pretty darn good. Double hurray!<div></div>

Just to join in - I also have front focus issues with my 105mm DC lens, on D200 and D3

bodies. I had Fixation in London fix the lens (re-calibrated) and it was fine, until I moved the

DC control -and the I had the front-focus issue again. The D3 AF adjustment can

compensate, but the images seem to lose the magic.

 

Given the number of us with this issue - do you think we could get Nikon to do something

about it?

Well I'm glad a read this thread. I too had a front focus issue with my brand new 105mm DC using my D3. I adjusted my D3 focus to +20 and it was still out. Changed the setting on the lens to F2 and now my D3 still needs to be set at +20, but the focus is bang on.

 

Thanks for your help.

 

Rob

Interestingly, my 105 DC seem to autofocus spot on at the neutral setting with my D3 (but not on the D200).

Just tried tried the Nikkor 105mm DC and I'm getting the exact same issue. With front DC on, camera (D80)

auto-focuses

inside the focus area indicator beautifully, but neutral and rear DC causes front focusing. Also, auto-focus

moves further

forward as you increase the rear DC.

 

Mark Gilbert, I wonder what the results were after Nikon calibrated the 135mm.

<p>I had the same problem with my 105 DC as most of you have. I made a lot of tests with D70, D2x and D700 and I found the following:<br>

Under tungsten lights all images show very visible front focus. If I set DC ring to F2, sharpness is much better, but not exactly the same as under natural light. Very light soft focus effect is applied, but this is only visible at 'pixel peeping'.<br>

But... under the natural light AF is dead on. At f2 images are all sharp!<br>

I talked to my NPS service representative and he confirmed that some lenses exhibit front or bac focus at artifical light.<br>

I tested my other AF lenses for front or back focus and they all needed some adjustment (with D700) using AF fine tuning from -10 to +10. Note that this tuning make only slight difference. I only use steps by 5, inbetween difference is almost invisible.<br>

The biggest adjustment (+15) was needed at 1.4/50, this lens suprisingly works perfect on D70 and D2x.</p>