Focusing issue on lens? Nikon 80-200mm f/2.8

[pennylane]

Hello,
So after much debating I said screw it and grabbed a Nikon 80-200mm f/2.8. I have a lowly D50, but I figured why not grab it? I'm going on vacation in August so I figured I'd get some good use out of it. So i did and it's here and it's quite bulky (especially when I attach my D50 to it) and the bokeh is awesome, but the focusing seems a bit off. The pictures I'm including are almost straight out of the camera. I shot them in RAW, converted to "medium" jpeg with no sharpening using Rawshooters Essentials 2006.

Here's a shot of a test chart using the Nikon 80-200mm f/2.8:
200mm, f/2.8, 1/800 s
I focused on the vertical line running down the middle. It's sharpest at about the 1 left of center. I heard that the lens is soft wide open at 200mm at the minimum focusing distance (which is where I was about), so I think that explains the general softness of the shot. I was careless and didn't shoot at other focal lengths. I will try to do that later today.

For comparison (sort of), here's a shot of the same test chart using my Tamron 17-50mm f/2.8:
24mm, f/2.8, 1/1000 s
The center is pretty sharp, but again, the 1 to the left of center looks sharpest.

Is this my camera or the lens? It seems like my camera, being a lowly D50, just isn't that accurate at focusing. I guess they figured most D50 users wouldn't attach an f/2.8 telephoto lens to their D50. Would sending the lens for calibration (it's under warranty) make a difference, or should I look into doing something with the body (it's no longer under warranty)?

Here are pics of a bottle of Safeway Aleve. These were all taken on a tripod, 100% crops. I tried to get the bottle at roughly the same size, but I was careless with the last picture.
Nikon 80-200mm: 200mm, f/2.8
Nikon 80-200mm: 200mm, f/11
At f/11 it's certainly sharper, but that seems to be due to the wider depth of field. (sorry for the f/11 being underexposed).

For comparison (sort of):
Tamron 17-50mm: 50mm, f/2.8
Nikon 70-300mm VR f/4.5-5.6: 240mm, f/5.6

Thanks.

*EDIT* here are more pics from a post later in the thread
I took pictures and they're all here.

I hope that's what you meant. Battery 1 is the rightmost battery (and closest to the camera). Battery 4 is the leftmost battery and farthest from the camera. Picture 1 of each album should always be on battery 1, picture 2 of battery 2, and so on. It seems like the sharpest battery is always the one left of the battery I'm focusing on.

I took pics at various apertures and focal lengths. The 50mm pic is using my Tamron 17-50mm. The rest are with the Nikon 80-200mm. There's also pics of the test-chart at various focal lengths, and the set-up. I used a flash to get fast shutter speeds and I think there's light reflected off the batteries.

Also, does the 80-200mm lens look as sharp as it should?

 

[Deadtrees]

I'll need to see more pictures to be sure but at this point, I think it may be the 'resolution problem' instead of AF problem. I'm not sure if I used a correct term, By saying 'resolution problem,' I mean the problem is lens elements not being where it should be. It usually happens when the lens is dropped or when it's just too old.

 

[Deadtrees]

BTW, as far as I know, Nikon AF lenses can't be calibrated like Canons'. You'll have to make adjustment on the camera if it's the AF issue.

 

[pennylane]

What kind of pics would you need?

 

[Deadtrees]

Line up at least 4 batteries slightly in front of each other but not blocking each other.
Take a shot from the 1st to the last time.

 

[soydios]

I own a push-pull AF 80-200mm f/2.8. I used it with my D50 on a tripod from the lighting booth in a large theatre, and noticed that just about all my shots were back-focused from the first day. I had shot with AF-C Dynamic Area. So, on the second day I shot with AF-C Closest Subject and got some really sharp ones, even at 1/60s f/2.8 ISO1600.

 

[pennylane]

Deadtrees,
I took pictures and they're all here.

I hope that's what you meant. Battery 1 is the rightmost battery (and closest to the camera). Battery 4 is the leftmost battery and farthest from the camera. Picture 1 of each album should always be on battery 1, picture 2 of battery 2, and so on. It seems like the sharpest battery is always the one left of the battery I'm focusing on.

I took pics at various apertures and focal lengths. The 50mm pic is using my Tamron 17-50mm. The rest are with the Nikon 80-200mm. There's also pics of the test-chart at various focal lengths, and the set-up. I used a flash to get fast shutter speeds and I think there's light reflected off the batteries.

Also, does the 80-200mm lens look as sharp as it should?

Thanks. I'm cutting and pasting this into the OP, also.

 

[jpeyton]

Back when I had a D50, and I had my first copy of an 80-200mm f/2.8, I remember being quite happy with the results.

Then came along the dreaded test charts, 100% crops, and focus tests Life is a little more complicated these days.

I sold that first copy (it had a stiff zoom ring, sloppy manual focus ring, and some element separation...none of which affected image quality) and bought a mint copy yesterday to replace it. Both were/are 4th edition copies; two-ring zoom with a tripod collar.

The new one has slight backfocus at 80, 105, 135, and strong backfocus at 200.

My D300 has an AF Fine Tune function, which can correct for slight focusing errors. Set to -20 (the maximum correction allowed), the backfocus errors are gone at 80, 105, 135, and there is slight backfocus at 200.

Will this show up in real world use? Not sure. Aperture, focal length and focusing distance will have an effect.

This seems to be less of an issue with newer AF-S lenses from my experience. My AF-S Nikkor 55-200mm VR focuses spot-on.

Looking at your test pictures, it looks like you're in a similar situation; slight focusing errors at the shorter focal lengths, but really strong errors at or around 200mm.

Ultimately, whether this shows up in your real-world photos depends on the subject. I imagine if you set it to 200mm at it's closest focusing distance, you'll be able to notice. But, for example, if you set it to 200mm and you're on a boat shooting someone that's wake-boarding, the longer focusing distance will flatten the subject and you won't notice it (or notice it as much).

EDIT: Did more research; it's not a repairable issue, and has more to do with the design of the lens than an individual defect. At close focusing distances, particularly at 200mm, the 80-200mm f/2.8 will have backfocus problems.

 

[pennylane]

Thanks soydios and jpeyton. I guess the solution is simple: buy a D300 . Is that fine tune function different for each lens or is it a universal adjustment?

I took some "real world" shots this weekend and I'll take a look at them tonight to see how they look. If there's nothing I can do then I guess I'll live with it. I don't think returning the 80-200mm f/2.8 and getting the 70-200mm f/2.8 (which is AF-S right?) is really an option. The 70-200mm f/2.8 is just too expensive for me.

I did email Nikon so I'll see what they tell me.

 

[jpeyton]

Another update.

Tested the lens outside at more typical focusing distances, and found out that my AF Fine Tune setting actually threw focusing at longer focusing distances out of wack.

I turned AF Fine Tune off. I'm very satisfied with the performance of this lens wide open at normal focusing distances.

Now I'm inclined to believe what I read about this lens is true. It has a design flaw that causes it to backfocus when autofocusing at its close focusing distance, and my D300 manual actually has this problem documented in it.

If you're at or near the close focusing distance, use manual focus to achieve critically sharp focus.

At longer focusing distances, AF performance should be fine.

If this is a problem for you, think about swapping it for a Sigma 70-200mm f/2.8 HSM, or a Nikkor 70-200mm f/2.8 VR if you can afford it.

 

[pennylane]

Thanks for the advice jpeyton. I need to try out the lens more. I still have to try soydios' suggestion on using the "closest distance" focus.

For push-pull owners, how fast/slow is the autofocus on that version? I hear that it's slower than the 2-ring version. Also, how difficult is it to use the push/pull to adjust the zoom? Are the any difficulties with using the push/pull while autofocusing (since you rotate the push/pull to focus in manual focus mode, if it's "locked" in autofocus mode, does it cause problems?)?

I also understand the the push-pull comes in 2 varieties, the non-D version and the AF-D version, with the AF-D version focusing faster. Is that true? If the 2-ring version is also AF-D, does that mean they should focus at about the same speed?

I can't quite afford the Nikon 70-200mm f/2.8 VR, but I don't really want to get the Sigma 70-200mm either (or any other 3rd party one). I do like the performance of the lens and I want the f/2.8 and the sharpness, but I'm now thinking that if the 2-ring version isn't quite perfect and I'm gonna compromise anyway, maybe I should just search for a used push-pull version of the 80-200mm and save perhaps a couple hundred dollars. I'm quite certain I'll upgrade to a 70-200mm f/2.8 VR eventually (as in, it a few years, when I can afford it), so it's sort of a temporary thing.

 

[soydios]

The AF isn't fast, but it's fast enough for everything but rapid-paced sports. The limiters are very well placed. Engaging autofocus disengages the ring from the focusing mechanism, so it's only the front element that moves and rotates during focusing. Push-pull zooming is easy and natural.

My push-pull 80-200mm f/2.8 is sharper than my D50 can resolve wide open, and performance is simply top of the line at f/4 or f/5.6.

 

[Deadtrees]

I don't know if the it's as sharp as it should be as I haven't used one.
On the other hand, it's clear that the lens back focuses @200mm. As far as know, Nikon lenses can't be calibrated as Canons'.
You'll just have to use it as it is or get a new one.