Is this a lens malfunction or wrong setting?

[Stagecoach]

Colin, your post No 2.

Hi Mari,

Probably easiest to have the shop test the lens and your camera together. It's something you can do yourself, but you need to be quite methodical about it (eg use a tripod -setup a suitable target (eg tape measure at an angle to the camera) (so we can see any degree of back/front focusing etc) - shoot it at the narrowest aperture.

Looking at the image something obviously isn't correct - but the only way to work out what is to eliminate things one at a time.

I'm now also aware of the previous problem encountered and apparently unsolved, nor mentioned in this thread, from the earlier graduation image.

Hopefully Mariko will undertake the test as suggested to enable a more researched conclusion to be reached by those assisting him and more importantly him understanding how the conclusion has been reached.

As for me I have an important date with a lady tonight so hopefully I may have a picture to post later

Grahame

[Colin Southern]

As for me I have an important date with a lady tonight so hopefully I may have a picture to post later

Grahame

I have an important date with a pizza - arriving in about 30 minutes!

I see that your intrepid leader just arrived here:

http://www.stuff.co.nz/national/poli...-arrives-in-NZ

[Stagecoach]

I see that your intrepid leader just arrived here:

http://www.stuff.co.nz/national/poli...-arrives-in-NZ

He can afford to have a holiday because with the way the polls have it he may as well take a break for a month as he's streaming so far ahead.

[ajohnw]

I'll find how to magnify the live view while taking a photo which I will take with the setting that Graham suggested, and re-post a photo again.

Few things - Image stabilisation isn't anti shock. If the camera is on a tripod it's best to turn the image stabilisation off.

Don't worry about the manual focusing comment just do it. It depends on how magnified the live view can be but there is a fair chance you will set a slightly fuzzy image easily and that a dead sharp one is more tricky. You might actually see chromatic aberration so go for the sharpest image possible.

Live view - hope this link works

http://books.google.co.uk/books?id=X...20view&f=false

One thing for sure you must rule the camera focusing out and live view is the only certain way of doing that - PROVIDING it's highly magnified.

Like most zooms that go from wide to moderate telephoto the lens drops off markedly at the longer end so for a test like this stay below 50mm. Looking at test results 35mm might show marginally better results than 18mm but F8 is definitely the aperture to use even though F6.3 is nearly as good. The main gain from F8 is more even light levels across the frame.

John
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[blacksheep]

I uploaded the photos to http://filebin.net/dnjmtqlba6

All VR off, Self-timerd, ISO200

DSC_0968.jpg - F11 at 35mm

DSC_0969.jpg - F11 at 18mm

DSC_0970.jpg - F6.3 at 18mm

[blacksheep]

Grahame,

Having been involved processing images from "that lens" in a previous thread, it's clear to me that there's a mechanical/optical problem somewhere (with it and/or with the camera).

Folks can talk about it here until the cows come home (figure of speech we use here in NZ) but in my opinion it's just wasting time because (a) we're not getting anywhere and (b) it's going to need to be looked at professionally regardless. Hence my suggestion to bypass this process and just move on to the bit that's going to have to be done anyway.

Sorry I thought it would be a bit more simpler to ask some opinions out here. It has still been very helpful for me, as I still have not come to travel to Nikon repair service in a different town yet. I figured a local shop I bought the camera from is not much of help. This forum gave me much more insight and I really appreciate that.
I promise I will bring it to the Nikon service point. Although I have already taken a test shot and posted...

[blacksheep]

Mariko,
I think you misunderstand it. John is referring to the function at which the mirror goes up, the camera waits for a while so the untit can stabilize again and then opens the shutter.
Nikon has a vibration reduction in the lens. You should disable that. If this malfunctions, you can get a photo like you have now, misty. And always disable the VR on a stative, it will work contra-productive.
Why didn't you try another lens yet?

George
George

! I understand that I misunderstood now.

I have not tried another lens yet because my friend has been using it and I have not had it back :'-(

[george013]

Mariko,
Go outside. Take 2 pictures of the same subject, with some depth in it. Just like your first one with a maximal shutterspeed of 1/125, iso 100. An average setting. One shot with VR on and one shot with VR off. Compare them. With a little bit of luck you can use the lens without VR.
If not you will need another camera and lens which are good to determine if your problem comes from the camera, the lens or both.

George

[ajohnw]

I uploaded the photos to http://filebin.net/dnjmtqlba6

All VR off, Self-timerd, ISO200

DSC_0968.jpg - F11 at 35mm

DSC_0969.jpg - F11 at 18mm

DSC_0970.jpg - F6.3 at 18mm

The 1st 2 look fine to me if a bit soft but PP would clean them up. The F6.3 one shows problems on the spokes on both sides but still looks miss focused to me.

I would still be inclined to do them again but focus with magnified live view to rule out AF problems.

Any time I have checked the focus on a camera all has been ok but I believe that Nikon's have facilities to adjust according to the lens fitted. The camera adjustment if needed is best left to a professional.

It's pretty easy to check AF using the method described here but check with a live view focus 1st.

http://www.northlight-images.co.uk/a...djustment.html

This needs setting up with a bit of care but is more precise than other methods.

John
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[Stagecoach]

I uploaded the photos to http://filebin.net/dnjmtqlba6

All VR off, Self-timerd, ISO200

DSC_0968.jpg - F11 at 35mm

DSC_0969.jpg - F11 at 18mm

DSC_0970.jpg - F6.3 at 18mm

Mariko,

Looking at the further set of images it can clearly be seen that even at f/11 35mm you have still got the problem of soft focus either side of centre, clearly visible just looking at the map. If it were my lens I certainly would not find that acceptable at that setting.

You really have no other choice but to have this lens repaired or scrap it if the difference in centre to edge sharpness is not acceptable to you.

Methods of focusing whether manual, auto or using live view is not your problem, your centre focusing on auto was fine. Even if the auto focus was out there in nothing you can do about it unless you are prepared to remove the base of the camera and start making mechanical adjustments.

Grahame

[Stagecoach]

Mariko,
Go outside. Take 2 pictures of the same subject, with some depth in it. Just like your first one with a maximal shutterspeed of 1/125, iso 100. An average setting. One shot with VR on and one shot with VR off. Compare them. With a little bit of luck you can use the lens without VR.
If not you will need another camera and lens which are good to determine if your problem comes from the camera, the lens or both.

George

George, I believe the last set of tests were done with VR off?

[george013]

But with a shutterspeed of 0.2 till 0.5. I don't know anything about a used tripod, mirror-up. Outside you can have a more normal setting and with depth.
Seeing the first photo, the unsharpness is overall and even. Looking for back- or frontfocus is useless to me. If that should be the problem, than the focus would be somewhere else.
George

[ajohnw]

But with a shutterspeed of 0.2 till 0.5. I don't know anything about a used tripod, mirror-up. Outside you can have a more normal setting and with depth.
Seeing the first photo, the unsharpness is overall and even. Looking for back- or frontfocus is useless to me. If that should be the problem, than the focus would be somewhere else.
George

Unless you have tried manually focusing using live view with a hight enough magnification to see the focus at the sensor pixel level I doubt if you realise just how critical it is, Black and white as used here is great for showing up problems. The main problem with focusing like that is that often the manual focus on AF lenses is rather coarse but it can be done and can also be used to check the focus accuracy of a lens and camera.

Rather than use such long exposures I would probably use flash at max sync speed for a test like this.

That focus test I linked to produces results like this with an accurate focus. In fact by comparing the bulls eyes it's possible to see that the lens was slightly out of square to the PC screen showing the target. Some lenses may generate more bulls eye patterns,



This was taken with a 180 view 16mm full frame lens to check the focus scale on the lens. It was about 1/2 a line width out. Not enough to worry about at normal apertures and distance ranges that a lens like this is normally used. However at the sort of distance this test was done at the scale would give a slightly out of focus image. The lens being discussed is being tested at relatively short distances.

John
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[blacksheep]

Mariko,

Looking at the further set of images it can clearly be seen that even at f/11 35mm you have still got the problem of soft focus either side of centre, clearly visible just looking at the map. If it were my lens I certainly would not find that acceptable at that setting.

You really have no other choice but to have this lens repaired or scrap it if the difference in centre to edge sharpness is not acceptable to you.

Methods of focusing whether manual, auto or using live view is not your problem, your centre focusing on auto was fine. Even if the auto focus was out there in nothing you can do about it unless you are prepared to remove the base of the camera and start making mechanical adjustments.

Grahame

Thank you Grahame,
I will bring the lens to Nikon repair service point within this month, and have it professionally quote for repairing.
So sad if I'll had to scrap it :P Missed the supermoon last night too :'-(

[blacksheep]

Unless you have tried manually focusing using live view with a hight enough magnification to see the focus at the sensor pixel level I doubt if you realise just how critical it is, Black and white as used here is great for showing up problems. The main problem with focusing like that is that often the manual focus on AF lenses is rather coarse but it can be done and can also be used to check the focus accuracy of a lens and camera.

Rather than use such long exposures I would probably use flash at max sync speed for a test like this.

That focus test I linked to produces results like this with an accurate focus. In fact by comparing the bulls eyes it's possible to see that the lens was slightly out of square to the PC screen showing the target. Some lenses may generate more bulls eye patterns,



This was taken with a 180 view 16mm full frame lens to check the focus scale on the lens. It was about 1/2 a line width out. Not enough to worry about at normal apertures and distance ranges that a lens like this is normally used. However at the sort of distance this test was done at the scale would give a slightly out of focus image. The lens being discussed is being tested at relatively short distances.

John
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Thanks John, I have looked at the focus in the max magnified live view while taking all those photos..it seems getting a right sharpness is not possible with this lens anyway... I will bring it to a Nikon service point this month.