Focusing Issues


spree86

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Feb 3, 2009
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Bishan
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#1
Hi guys, my nikkor 35mm f1.8 has front focusing issues so I brought it down to NSC for calibration since its still under warranty. Upon checking, the technician called me and said that the focusing is confirmed to have front focusing issue but its still within factory standards, so nothing was done to it.

Question is, what do I do now? Bring it down to a third party servicing shop? But that would void the warranty right?
 

Dec 9, 2004
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Sembawang
#2
Hi guys, my nikkor 35mm f1.8 has front focusing issues so I brought it down to NSC for calibration since its still under warranty. Upon checking, the technician called me and said that the focusing is confirmed to have front focusing issue but its still within factory standards, so nothing was done to it.

Question is, what do I do now? Bring it down to a third party servicing shop? But that would void the warranty right?
You can't insist on having it calibrated?

If it is a real issue on ur pics, maybe you can show them sample pics to show how badly it affected ur pics?
 

spree86

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#3
You can't insist on having it calibrated?

If it is a real issue on ur pics, maybe you can show them sample pics to show how badly it affected ur pics?
I did insist that I wanted the lens to be calibrated as the focusing is obviously off at wider apertures and composing my shots is a pain. The technician said he will make minor adjustments but when I collect the lens seems like nothing had been done, the focusing was still off by the same degree. So I'm thinking if I send it back again, they are going to tell me the same thing again.
 

#4
Perhaps you should post some pictures and lets see to what extent is the front focusing affecting your photos. At the widest aperture focusing can become a tricky issue, some of us resort to using manual focus at such wide apertures. If your camera features a AF fine tune, you could use that to make minor adjustments.
 

spree86

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#5
Here's a picture shot at f1.8, the focus point is on the number 5 button. As you can see, the front focusing is not much but enough to be really irritating. I'm using a D80, so no chance of doing AF fine tuning in the camera:(

 

grantyale

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Oct 4, 2004
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#10
Here's a picture shot at f1.8, the focus point is on the number 5 button. As you can see, the front focusing is not much but enough to be really irritating. I'm using a D80, so no chance of doing AF fine tuning in the camera:(

Have you tried focusing on a flat subject? For example, a small piece of black tape on the wall.

The actual focusing sensor is longer than the marker in the viewfinder and may not be well-aligned. Part of the AF sensor may be seeing "8" on the remote when you think it is centered around "5".

If you're sure there's problem with AF calibration, voice it up to the service executive/manager.
 

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spree86

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#11
Have you tried focusing on a flat subject? For example, a small piece of black tape on the wall.

The actual focusing sensor is longer than the marker in the viewfinder and may not be well-aligned. Part of the AF sensor may be seeing "8" on the remote when you think it is centered around "5".

If you're sure there's problem with AF calibration, voice it up to the service executive/manager.
Thanks!! I will try that out and will update here whether its the same problem or not. I will voice it up if I send it in again and they tell me the same story.
 

wdEvA

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Sep 1, 2006
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#12
try using a focusing chart to test.
bring the results down and discuss with NSC, and if needed, request to have a focus test together with the technician.
 

#13

spree86

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#14
try using a focusing chart to test.
bring the results down and discuss with NSC, and if needed, request to have a focus test together with the technician.
This is a good test chart that I usually use http://regex.info/blog/photo-tech/focus-chart, and this is another one which is quite common amongst CS users http://focustestchart.com/chart.html
Thanks!! I will do the focusing on the test chart and bring it down to NSC again. See if they will do the calibration this time round.
 

Dec 9, 2004
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Sembawang
#15
Just got a 35mm f1.8 and having similiar issue with TS. Got slight front focus. After seeing TS's plight, I was thinking whether I should try my luck and send it in to NSC, or just to manually compensate whenever I use this lens..

I decided to try and luck and send the lens and d5000 for calibration. NSC just call me and they say they calibrate the body instead??? Kaoz, so I told them I got 2 other lenses (focusing is ok) and ask him whether this will affect these 2 lenses. He say should be still within specs and ask me to bring the other 2 lens for testing when I go down to NSC???? For the benefit of 1 lens, I may have to sacrifice my other 2 lenses (1 of it is sigma somemore and calibration is by appointment only).....I told him I want the calibration for the body to be reverted, and to tune the lens only...

I did some search in CS and I thought NSC will usually calibrate the lens, instead of body?
 

daredevil123

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Oct 25, 2005
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lil red dot
#16
If focus is off for all lenses, then calibration on the body is the way to go. Better to check with other Nikon lenses to make sure the calibration is done right, since the d5k does not come with AF fine tune. Agree that NSC should have called you first. Anyway, NSC ask you to bring the other lenses down, you should.
 

Dec 9, 2004
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Sembawang
#18
If focus is off for all lenses, then calibration on the body is the way to go. Better to check with other Nikon lenses to make sure the calibration is done right, since the d5k does not come with AF fine tune. Agree that NSC should have called you first. Anyway, NSC ask you to bring the other lenses down, you should.
It is partially my fault also as I take for granted that NSC will only tune the lens, therefore I didn't mention to the lady about this when I send it in....The technician just call me and say he has reverted the tuning for the body and only tune the lens now.....anyway to be on safe side, I will just bring all my other lenses to test as well.....Thks!
 

daredevil123

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Staff member
Oct 25, 2005
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lil red dot
#19
scramblur11 said:
It is partially my fault also as I take for granted that NSC will only tune the lens, therefore I didn't mention to the lady about this when I send it in....The technician just call me and say he has reverted the tuning for the body and only tune the lens now.....anyway to be on safe side, I will just bring all my other lenses to test as well.....Thks!
Hope it works out for you this time round. ;)
 

yrh0413

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Oct 21, 2004
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#20
I did some search in CS and I thought NSC will usually calibrate the lens, instead of body?
Not really, they will calibrate your body not the lens unless there are odd decentering issues and stuff. Back/front focusing will be calibrated on the body and it will affect only on how the camera body interacts with that particular lens.

Say if you send in a 12-24mm lens for calibration, it should not mess up the focusing of your 18-55mm etc. That's what I have been told by the technicians when I was shooting with Pentax system few years back.
 

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