How can I tell that my Camera and Lens need to be calibrated?


Jan 26, 2009
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#1
How can I tell that my Camera and Lens need to be calibrated?

I have a Nikon D90 with 80-200mm f/2.8 ED D-AF Lens. This pass few months I’ve noticed all my picture is not sharp even I shoot in broad daylight with a tripod and shutter set to 1/1000 and above. I bought my lens from CS member 2 years ago and also I bought my D90 on the same year 2010.

Please advise.
 

rhino123

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Sep 1, 2006
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#2
How can I tell that my Camera and Lens need to be calibrated?

I have a Nikon D90 with 80-200mm f/2.8 ED D-AF Lens. This pass few months I’ve noticed all my picture is not sharp even I shoot in broad daylight with a tripod and shutter set to 1/1000 and above. I bought my lens from CS member 2 years ago and also I bought my D90 on the same year 2010.

Please advise.
A photo would tell a lot.

Also provide the following information with your photo,

1) Exif information
2) Your focus point

Plus do u encounter this problem in the past?
 

soeypixels

Senior Member
Jun 24, 2007
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#3
just bring it to down to NSC
brought all my equipments for check up , cleaning and parts replacement

for cam and lenses check, they can do it for u on the spot
if theres a problem u probably got to leave your gear there
 

Wizongod

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Nov 25, 2011
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#4
Here's how:

1. Find a focus chart online (preferably in a size that your printer can handle, e.g. A4)
2. Print it out
3. Lay it on a flat surface
4. Set your camera to focus dead center (with spot AF)
5. Place your camera on tripod and aim it at an angle downwards to the focus chart (estimate 45 degree will do. No need to be that precise)
6. Open up your aperture all the way.
7. Focus on the center of the chart where you're supposed to focus on.
8. Take a few shots, each time refocusing (manually unfocus the lens, and let the AF focus back)
9. Open it up in your computer and zoom in to 100%
10. Check for front, or back focus.
11. If your shots are mostly fine, then no need to re-calibrate, otherwise, either calibrate yourself (if your camera has micro-adjustments) and test again, or bring it down to the service center.

Here's a link to a focus chart: Jeffrey Friedl's Blog » Jeffrey’s Autofocus Test Chart
 

Wizongod

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Nov 25, 2011
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#6
It looks fine. Maybe a tiny little bit front-focusing. But zoom lenses are difficult to calibrate perfectly for all focal lengths. Try taking at 50mm to check if there's any focus problems. If it also is front-focusing just a little bit, then you can calibrate it to go back a little. Your focus is fine at 17mm though, I'm only nitpicking.

I'd advise you to try using the focus chart I linked because that one has more details for you to look and assess. Also, align your focusing chart straight on with the camera, and in the center of the frame, currently it's slanted a little to the left, and a little too much to the left of the frame.
 

buzzmario

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Mar 12, 2011
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#8
It looks fine. Maybe a tiny little bit front-focusing. But zoom lenses are difficult to calibrate perfectly for all focal lengths. Try taking at 50mm to check if there's any focus problems. If it also is front-focusing just a little bit, then you can calibrate it to go back a little. Your focus is fine at 17mm though, I'm only nitpicking.

I'd advise you to try using the focus chart I linked because that one has more details for you to look and assess. Also, align your focusing chart straight on with the camera, and in the center of the frame, currently it's slanted a little to the left, and a little too much to the left of the frame.
hi, as i read the link, there no pix showing how to take the chart from, ie at a angle of 45 etc. i use a link thst show in pix that i lay the chart on the table. the cam mount onto a tripod, at angle of 45 , focusing and snap off. so your "align your focusing chart straight on with the camera" mean what?

thanks , a newie here.
 

rhino123

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Sep 1, 2006
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#9
hi, as i read the link, there no pix showing how to take the chart from, ie at a angle of 45 etc. i use a link thst show in pix that i lay the chart on the table. the cam mount onto a tripod, at angle of 45 , focusing and snap off. so your "align your focusing chart straight on with the camera" mean what?

thanks , a newie here.
Actually... no need to be so scientific lah. Just focus your lens on a subject, be it a ruler, a calculator or whatever, remember your focus point, then check your result on the big screen, if the letter, number or whatever you are focusing on and had achieve focus lock are still blur or soft as compared to other wordings and letters or whatever around it, then you probably need to do some calibration.

That say... please be sure to mount your camera on a tripod, use a remote if possible, and shoot, so as to eliminate as much possibility to camera shake as possible.
 

Octarine

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Jan 3, 2008
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#10
Actually... no need to be so scientific lah. Just focus your lens on a subject, be it a ruler, a calculator or whatever, remember your focus point, then check your result on the big screen, if the letter, number or whatever you are focusing on and had achieve focus lock are still blur or soft as compared to other wordings and letters or whatever around it, then you probably need to do some calibration.
I don't think that a rules is helpful. Reason: the markings on the ruler are just 1mm apart, the AF will lock on any of those since the sensor area is bigger than a single line of 1mm. As result (easy to see if multiple shots are taken), the AF lock will 'jump around' along the ruler scale.
The focus test chart has a single line, aiming to catch the center AF with this huge 'bait'. This eliminates distraction by any other shapes or markings.
TS: Roundabout 45 degrees is fine. Important is: make sure the upper / lower edge of the sheet will not come close to the focus area (especially when using wide angle lenses). Tripod helps to have consistent positioning of the camera.
 

buzzmario

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Mar 12, 2011
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#11
I don't think that a rules is helpful. Reason: the markings on the ruler are just 1mm apart, the AF will lock on any of those since the sensor area is bigger than a single line of 1mm. As result (easy to see if multiple shots are taken), the AF lock will 'jump around' along the ruler scale.
The focus test chart has a single line, aiming to catch the center AF with this huge 'bait'. This eliminates distraction by any other shapes or markings.
TS: Roundabout 45 degrees is fine. Important is: make sure the upper / lower edge of the sheet will not come close to the focus area (especially when using wide angle lenses). Tripod helps to have consistent positioning of the camera.
as the cam is mount on trpiod, do i on the OS, mine is the sigma. thanks
 

daredevil123

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Oct 25, 2005
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#13
Actually... no need to be so scientific lah. Just focus your lens on a subject, be it a ruler, a calculator or whatever, remember your focus point, then check your result on the big screen, if the letter, number or whatever you are focusing on and had achieve focus lock are still blur or soft as compared to other wordings and letters or whatever around it, then you probably need to do some calibration.

That say... please be sure to mount your camera on a tripod, use a remote if possible, and shoot, so as to eliminate as much possibility to camera shake as possible.
There is a reason why focus test chart only have one thick black line in the middle where you focus on, and no lines around it...

You should also download the same focus test chart, and read the information in the first few pages to understand how focus sensors really work and how they are positioned in a camera.

http://focustestchart.com/focus21.pdf
 

Octarine

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#14
as the cam is mount on trpiod, do i on the OS, mine is the sigma. thanks
A tripod is meant to keep a camera stable, your OS is meant to counter handshake. So if you mount your cam on tripod ..? :)
Another observation: people report that pictures taken on tripod with IS/OS switched on are not sharp. Switching off the IS/OS helps immediately.
Reason: IS/OS 'anticipates / expects' handshake to counter it. If there is none, then IS/OS will cause soft images. Newer Canon lenses are said to notice when mounted on tripod.
 

Wizongod

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Nov 25, 2011
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#15
hi, as i read the link, there no pix showing how to take the chart from, ie at a angle of 45 etc. i use a link thst show in pix that i lay the chart on the table. the cam mount onto a tripod, at angle of 45 , focusing and snap off. so your "align your focusing chart straight on with the camera" mean what?

thanks , a newie here.
You don't have to get 45 degree exact, because you're not trying to tell how much your lens is off by, just whether it is a little, or alot. When I say align your focusing chart straight on with the camera, I mean the top and the bottom sides of the paper should be parallel to the camera's top and bottom. That's why I recommend the test chart in my link, because it has the two black "sights" on the top and bottom to help you align. Other than that, like I said, your lens is fine. I'm only nitpicking a little.
 

buzzmario

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Mar 12, 2011
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#16
A tripod is meant to keep a camera stable, your OS is meant to counter handshake. So if you mount your cam on tripod ..? :)
Another observation: people report that pictures taken on tripod with IS/OS switched on are not sharp. Switching off the IS/OS helps immediately.
Reason: IS/OS 'anticipates / expects' handshake to counter it. If there is none, then IS/OS will cause soft images. Newer Canon lenses are said to notice when mounted on tripod.
thank Octarine and wizongod.

btw, i have a p and s , s100, hence for this s100, not way i can off the is/os , thus there is not way i can control this ?
 

Octarine

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#17
thank Octarine and wizongod.
btw, i have a p and s , s100, hence for this s100, not way i can off the is/os , thus there is not way i can control this ?
I don't think think you need to worry about focus issues with your S100. The large depth of field of these cameras will cover all inaccuracies of the AF system.
The contrast detection AF system of the S100 also works differently. The constant cycle of 'check - move lens - check - move lens' gives quite accurate results (although slow).
 

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