Blur image at the corners


bbbddd

New Member
Apr 9, 2010
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Hi CSer

I realize that the corner of my pictures are blur whenever I use a Tokina 11-16. My subject is also out of focus after the auto focus lock on it. I am currently using a D7000. I tried shooting using nikon 18-105 kit lens and there no problem with the pictures. So im wondering if there is a problem with my Tokina 11-16. May I know whats the main cause of the problem ?

This image is taken with nikon 18-105 kit lens. Settings: ISO 200, f/4.5, Exposure time 1/125s, Focal length 35mm
2w6ffad.jpg


This image is taken with Tokina 11-16. Settings: ISO-100, f/3.5, Exposuretime 1/125s, Focal Length 16mm
2195opd.jpg
 

Where is your focus point? Even on the first picture the guy with red shirt is soft whereas the bystanders in background appear sharper. Second pic the same: the background is sharper than main object. Please verify which focus point you use. In addition, you can download a focus test chart, follow the instructions and test your lenses. (Google helps.)
 

Also, consider that you are shooting at f/3.5 - consider your DOF, when you are referring to points close to you while your focal point is the wall 20m away. Also factor in wide angle distortion.
 

My focal point is at the guy playing the instrument. I have several shots which focuses on him but it seems OOF
 

User problem. I guess must be auto mode, multi point focus
 

My focal point is at the guy playing the instrument. I have several shots which focuses on him but it seems OOF

Did you use spot focus? In both pics, the focus is on the back sign.
 

Did you use spot focus? In both pics, the focus is on the back sign.

I was shocked to see the photos too. It can't bee i miss the focus point for all my shots.
 

I was shocked to see the photos too. It can't bee i miss the focus point for all my shots.

What focus mode did you use? This is the 3rd time we are asking...
 

Try iso 800 with f8 on av mode and see if it's still like this....
 

The only solution to ts problem is read the user manual and understand how to operate a dslr.
In this case ts had lost control and the dslr had taken over the situation and the result isnt what ts expected (of course)
 

Could be back-focusing issue.. this is only if you can confirm that you have focused on the man playing the instrument.. My friend's Tokina 11-16 also had this issue, and he brought his camera (D90) with the lens to Nikon SC for adjustment.. As what Octarine said, you can also download and print Focus test chart (http://focustestchart.com/focus21.pdf) and test your lens on it.. see if it back-focuses.
 

Could be back-focusing issue.. this is only if you can confirm that you have focused on the man playing the instrument.. My friend's Tokina 11-16 also had this issue, and he brought his camera (D90) with the lens to Nikon SC for adjustment.. As what Octarine said, you can also download and print Focus test chart (http://focustestchart.com/focus21.pdf) and test your lens on it.. see if it back-focuses.

Does front or back focusing even applies to this situation? If ts really focus on the man and end up the signboard is in focus, i wonder how they going to adjust the lens
 

Could be back-focusing issue.. this is only if you can confirm that you have focused on the man playing the instrument.. My friend's Tokina 11-16 also had this issue, and he brought his camera (D90) with the lens to Nikon SC for adjustment.. As what Octarine said, you can also download and print Focus test chart (http://focustestchart.com/focus21.pdf) and test your lens on it.. see if it back-focuses.

The adjustment is made on the camera's body or the lens ?
 

Does front or back focusing even applies to this situation? If ts really focus on the man and end up the signboard is in focus, i wonder how they going to adjust the lens

I thot that exactly what back focusing means? If the camera AF actually misses the focusing point and focuses slightly behind the subject supposedly in focus? The adjustment would be both on body and lens, not only the lens. This pic could be one of the many examples of back focusing problem..
 

I thot that exactly what back focusing means? If the camera AF actually misses the focusing point and focuses slightly behind the subject supposedly in focus? The adjustment would be both on body and lens, not only the lens. This pic could be one of the many examples of back focusing problem..

So if i bring the Tokina 11-16 down to NSC, will they adjust the tokina as well? or do i have to go to tokina's service ?
 

So if i bring the Tokina 11-16 down to NSC, will they adjust the tokina as well? or do i have to go to tokina's service ?
From my friend's experience, NSC will adjust the camera but they need the lens to try out their adjustment. Before going, try on the focus test chart first and see if it's really back focusing issue. Shoot at 45-degree angle wide open.
 

I thot that exactly what back focusing means? If the camera AF actually misses the focusing point and focuses slightly behind the subject supposedly in focus? The adjustment would be both on body and lens, not only the lens. This pic could be one of the many examples of back focusing problem..

If the lens or body had focusing issue, the difference in off focus distance would not be this big. Thats why your focusing chart is only this big. A goid example of focusing problem of lens or body would be at widest aperture, if you focus on a model's eye, the image turns out the ear in focus. This is the focus error distance we are refering to. Either the lens or / and the body needs micro adjustment.

Ts prob here is likely he accidentally focus on wrong subject.

If i'm wrong pls correct me. Open for discussion
 

Problem with ppl is they always blame the equipment for not producing what they want. But the fact is 95% of the time is user problem and ppl always fail to realise
 

front or back focus won't be that bad until 10-20feet away, unless is a lemon lens,

you could be accentually switch to AF-C, doing a auto focus and recompose. or even the switch to manual focusing with noticing it.

check how the way to shoot, and also shoot a focusing test chart.