D7000 Auto-focus Problems or Unwarranted Expectations?

QuintonHurst

Is it normal for the Nikon D7000 to randomly back-focus when using the viewfinder (phase-detection AF system)?

The two lenses I am using are a Sigma EX 17-50mm f/2.8 DX and a Sigma EX 70-200mm f/2.8 FX.

It is nearly 100% guaranteed to do it in low-light, which by "low light" I am referring to your everyday indoor lighting of 3-4 bulbs in a ceiling fan fixture and maybe a lamp in the room.

The back-focusing is most pronounced when I am at 17mm wide open. Pictures are unusable under these circumstances.
I used the 17mm end of the Sigma wide open at 2.8 in daylight today and took a picture of a wall that I had positioned the camera parallel to, and it was extremely out of focus. However, I switched over to LiveView and it was perfectly fine. Both shots were taken on a tripod with the exposure delay function on.

Whenever I use LiveView in the same setting, my picture is as sharp as one would reasonably expect. This is not an issue of "softness". You can clearly see something in the background being tack sharp while the face that is centered in the camera and takes up at least 50% of the image is completely soft.

I've sent the camera in to Nikon Service Repair once because of this problem and this is how it comes back, the same way.

Is this something I should live with or is it cause enough to return the item?

PB_PM

Nikon cannot really help you when it comes to adjusting third party lenses. For them to determine where the issue is, whether it is the camera or the lenses that are misaligned, they need both the body and the lenses.

Liveview AF is different, so having one work while the other does not is perfectly normal.

QuintonHurst

I was wondering if maybe I should purchase a Nikon lens to test on the body. In theory, it shouldn't exhibit random AF problems that AF fine-tune values of -20 don't fix on my Sigma lenses right?

My other option is to send the body in (which is supposed to be up-to-spec now) to a Sigma repair center along with my lenses to have them calibrated to the body. The only thing that doesn't seem right is the coincidence of both lenses requiring calibration.

Msmoto

I would make certain you have the center focus point active, single point, single servo, Auto AF off, and see if this helps. It sounds like the camera is finding a focus point other than your subject and this may be more of a problem in low light. Also, make certain the AF focus assist light is on. About p 210.

heartyfisher

Did you get those lenses with the camera ? or were they bought before the D7000..
I am asking because sigma reverse engineers the nikon autofocus so if the lenses were manufactured before the D7000 then they are not calibrated for that camera. send it in to sigma for calibration for your D7000

QuintonHurst

AF-S @ center focus point is what I used. It does it outside for "landscapes" even. (In my case, the outside wall of the house. lol)
The lenses were purchased all at the same time.

I'll post the images I'm about to take and send to Sigma. I've been chatting with them about the problem. If it is their lenses, they'll calibrate them for me at no charge thankfully.

JonoC

Hi Quintonhurst

I only got my D7000 last sept, and find the same issue, I think you may find quite a few similar reported issue on the net. I asked nikon to service the camera but came back the same. I do have both nikon and the sigma 17-50dx, and only find issue with the sigma, but managed to adjust with AF fine tune by -18 to correct the focus.. So my guess is the nikon and sigma combination? Good luck in fixing this, can you let us know if you have any luck with sigma, just curious if they can help! Good luck!

dumeril7

According to my local camera repair guy, this is a well-known problem with a lot of (but not all) D7000s, although Nikon has never issued a recall or acknowledged it. I've done very meticulous and controlled testing of my D7000 in a variety of conditions, eliminating as many variables (including myself) as possible, and it's clear: It definitely back-focuses. It helps that in my case, I had a D5100 (same sensor as a D7000) that focused well and on-target with all my lenses so I could compare and see what the lenses were capable of. I am able to compensate using the AF Fine Tune feature, but for a couple of the lenses the Fine Tune setting is maxed out and it's still just not quite there. Mine will be going back to Nikon eventually. If I have to return it multiple times until they get it right, so be it.

QuintonHurst

I'm just going to wait until I get the Nikon 35mm lens in Monday and see if it is the camera or third-party lenses. If it's the camera, I'm going to go on one last photo shoot and then return it to B&H who has already given me an RMA. If it's the Sigma lenses, one of which is requiring about -20 in some conditions, I will send both the camera and lenses to Sigma to have them calibrated to my camera, free of charge under warranty and tell B&H what's going on now. In either case I'm going to be without my camera for a while.

On a side note, I'm thinking about buying a Nikon D3200, D5100, or D5200 for something as a reliable backup although I'm afraid it will do just the same thing. Anyone have any experience with any of those have back-focusing issues like the D7000 or is it just the D7000 only? It sucks not having your camera when you have all of your other equipment lying around not being used and have plenty of stuff to take pictures of.

QuintonHurst

Btw, this is what Nikon did to the camera when I sent it in...

ADJ AUTO FOCUS OPERATION
CKD FOCUS SYSTEM
CKD SHARPNESS
CKD IMAGE TEST
CLN IMAGE SENSOR
GENERAL CHECK & CLEAN

I do know that the repair bank it was put in was B2 which means major parts replaced although apparently that wasn't detailed on my receipt?

Dredden85

Do any of the other lens systems have the same issue e.g. Tamron?
(I am expecting a fresh D7000 from B&H soon.)

TaoTeJared

Sigma has a long history of their consumer zooms having bad focus issues. The three I had all where garbage. And I mean garbage. You should try a 18-55vr or a 18-105vr Nikon lens to see if it has an issue.

I have seen and help a few who have focus issues who have played with the AF fine-tune. My experience is, if you don't have a true TEST set-up you shouldn't be touching it.

If you are testing focus, you should follow theses:
-ISO at native settings = 100 or 200 depending on model
-Shutter speed should be 2x the focal length for DX, 1.5x the focal length on FX to give a realistic optimum result. I.e. If shooting at 50mm on DX your shutter should be 1/100 to get consistent sharp photos.
-Use a sturdy or weighted down tripod with timer release or remote cord and delayed exposure.

On normal shooting, if those above are not met, you should expect to have quite a few poorly focused photos. 99 times out of 100 it is the photographer's fault the images are not focused not the camera or lens.

Look at the EXIF of the shots (shot settings) if they read something like ISO 3200, 50mm, F/4, 1/30th shutter, your image should be blurry.

If anyone wanted to post some photos, some may be able to see.

DaveyJ

I have had so bad luck with Sigma lens on 35mm I won't buy another. On Nikkor lens the D7000 focus is excellent. I own tow of them and all the lens work well. That includes D lens, DX lens, FX lens, etc. I have recently shot with Tokina and they have been excellent. I also have talked to a number of serious photographers and the are having great luck with Tokina and Nikkor lens on D7000.

QuintonHurst

My last test from the end of the week would suggest that in some cases this may not be an auto-focus problem.
Very odd...

17mm
f/2.8
ISO 100
1/200th second
Exposure Delay: On
Subject distance: 9.5ft

http://dl.dropbox.com/u/52825519/Sigma 17-50mm - 1 - Viewfinder.JPG
http://dl.dropbox.com/u/52825519/Sigma 17-50mm - 1 - LiveView.JPG

According to a DoF chart, I should have everything from ~6ft to ~21ft in focus. Clearly it's not sharp though.
Also, don't look at the plant/bush on the side. It was windy so blurring is expected on it.


@ DaveyJ. A Tokina 11-16mm DX II is on my list for a good wide-angle zoom. ;D

Dredden85

The live view is sharper than the view finder shot. The detail in the brick comes out in the live view. I have used the Sigma 70-200mm 2.8 on my mother's D7000. In both live view and view finder the shot looked identical and I did not notice any focusing differences. Of course it doesn't help that I don't have the images with me.
You are correct, it is very odd.

QuintonHurst

Aha...this was taken with my new Nikon 35mm f/1.8G DX lens. I focused on one of the bottles of hair gel and if you look around you can see the focus is actually on the ASUS box which is approximately 11 inches behind the plane that the bottle's writing is on.

I'm thinking maybe that the camera should go back. I barely have any warranty left on it and who knows how many more tries it's going to take for Nikon to get it right.

Anyone have any ideas that would say it is NOT the camera?

Dredden85

Wow two posts at the same time. When does that happen?

I guess warrenty left is better than no warranty left and stuck with a bill for repair. If it were me, I would send it back while the warrenty was still good.

Dredden85

"According to my local camera repair guy, this is a well-known problem with a lot of (but not all) D7000s, although Nikon has never issued a recall or acknowledged it. I've done very meticulous and controlled testing of my D7000 in a variety of conditions, eliminating as many variables (including myself) as possible, and it's clear: It definitely back-focuses. It helps that in my case, I had a D5100 (same sensor as a D7000) that focused well and on-target with all my lenses so I could compare and see what the lenses were capable of. I am able to compensate using the AF Fine Tune feature, but for a couple of the lenses the Fine Tune setting is maxed out and it's still just not quite there. Mine will be going back to Nikon eventually. If I have to return it multiple times until they get it right, so be it".

dumeril7, has your "local camera reapir guy" noticed any trends in serial numbers that come through with the focus issue e.g. a certiain lot that has the issue vs. the lot that does not?
Not sure if this even feasible- just brainstorming.

QuintonHurst

Wow two posts at the same time. When does that happen?

I guess warrenty left is better than no warranty left and stuck with a bill for repair. If it were me, I would send it back while the warrenty was still good.

I mean go back to B&H for an exchange which they have setup for me right now. They're just waiting for me to send it in and then I'll be getting a replacement one.

I'll have you all know this is a refurbished Nikon D7000. I'm wary of these refurbs now or at least those of the D7000s.

Dredden85

I hope the replacement is in good order. I think it was KnockKnock who recieved a refurbed one too that had a focus issue as well. His post is in another thread:
http://forum.nikonrumors.com/discussion/92/is-the-d7000-worth-buying/p5

Good luck!

KnockKnock

Yup, similar experience, though I had no Sigma lenses to question. My breaking point was running through a series of a range of AF fine tune adjustments (see that other thread), and none of them came close to the sharpness of Live View.

To be fair, I had some decently sharp shots too, mostly with the 35/1.8, but they were f/5.6-8.0 on a sunny day so something would likely be in focus. I think I snapped though, before doing all the work. Once I saw that a good calibration target and software to help zero in on fine-tune would run me $100 to say nothing of my time, which I do value fairly dearly, I just got fed up. Thank heavens for Adorama's return policy (I have no issues with B&H either).

It reminded me of a very bad experience I once had with a $1000 apple trinitron a/v display 15 years ago. If you had told me, that come my 8th replacement (those things were heavy too), that I could have had my money back within the first 30 days, I would have gotten back a piece of my sanity and happiness.

I'm chilling out a little now. Fairly convinced that there's a fine refurb out there, or that a 'new' $900 D7000 would be excellent, but while I'm waiting maybe I'll hold out to see what the future holds. We shall see.

spraynpray

When you go for a new body you get something that nobody has dropped/hammered the buttons on/has no history of problems. You go for a refurb, and the least you can expect is that it had some kind of problem which made the buyer return it. So you pin everything on the problem having been repaired. I know many people will now feel the urge to post here that they purchased 'whatever' body refurbed and have had no problems but you have to see that there is most likely some problem (that has hopefully been fixed) in the cameras history. Look at all the posts on this forum about oil and the D600 - yous guys are probably passing the same cameras round in a huge circle! There are prolly only 20 bad ones out there )

Dredden85

...yous guys are probably passing the same cameras round in a huge circle! There are prolly only 20 bad ones out there )

Good point!! LOL
)

QuintonHurst

Aha...this was taken with my new Nikon 35mm f/1.8G DX lens. I focused on one of the bottles of hair gel and if you look around you can see the focus is actually on the ASUS box which is approximately 11 inches behind the plane that the bottle's writing is on.

I'm thinking maybe that the camera should go back. I barely have any warranty left on it and who knows how many more tries it's going to take for Nikon to get it right.

Anyone have any ideas that would say it is NOT the camera?

Oh here's the link. My bad xD
https://dl.dropbox.com/u/52825519/EQH_1219.jpg

QuintonHurst

B&H received my camera and as of today has placed the order for my new Nikon D7000.
I'll let you all know the verdict when I get it in. I hope it works!
If not, I'll probably pick up a refurbished Nikon D5100 because I sure could use a camera with a vari-angle LCD screen and I'll wait for the D7100 to come out to be my main camera.

Gab

D7000 back focusing is a common problem. Mine had it too, I sent in and now it works fine. (with Nikon lenses, not so much with tamrons and sigmas)