Check on AF accuracy

[JJLoke]

Hi guys!

I went to a concert on last night and was happily snapping pictures away on my 85 1.8 and 28 1.8.

While browsing through the pictures I realise that most of the pictures are a little bit soft, but very acceptable.

I switched to Live View mode and all the pictures came out tack sharp.

So is there something wrong with the AF sensor? Im using center point all the way.

Thanks for the help!

 

[daredevil123]

Hi guys!

I went to a concert on last night and was happily snapping pictures away on my 85 1.8 and 28 1.8.

While browsing through the pictures I realise that most of the pictures are a little bit soft, but very acceptable.

I switched to Live View mode and all the pictures came out tack sharp.

So is there something wrong with the AF sensor? Im using center point all the way.

Thanks for the help!

maybe you can post some of your blur pics, and a sample of your sharp pics. With exif info.. so we can take a look and figure out why?

 

[JJLoke]

I have uploaded 2 photos on Flickr

the sharper one is using liveview and the oof is using center point AF.

http://www.flickr.com/photos/56155021@N07/5194201510/in/photostream/

Here is the 2 photo data:

Canon 85mm f1.8 USM

Canon EOS 450D

Shutter Speed - 1/320 sec.
Lens Aperture - F/2.2
ISO Speed - ISO-1600
Metering Mode - Partial
Exposure Program - Manual

 

[daredevil123]

I have uploaded 2 photos on Flickr

the sharper one is using liveview and the oof is using center point AF.

http://www.flickr.com/photos/56155021@N07/5194201510/in/photostream/

Here is the 2 photo data:

Canon 85mm f1.8 USM

Canon EOS 450D

Shutter Speed - 1/320 sec.
Lens Aperture - F/2.2
ISO Speed - ISO-1600
Metering Mode - Partial
Exposure Program - Manual

There is a big chance your lens AF accuracy is off (front focusing or back focusing).

You should confirm this by testing your lens on a focus test chart (download here).

If there indeed is a problem, send it into CSC for a calibration.

 

[JJLoke]

I have send down my lens for calibration once and the technician reset the lens.

If its lens problem, shouldnt the live view be oof as well?

 

[zhuangzhou]

i think it has something to do with where you set your focus point as well.

 

[JJLoke]

Its center point AF all the way

If that is unreliable in low light, the rest wun do much better

 

[sherchoo]

At F2.2 the DOF is quite shallow and the margin for AF error if quite big. If I were to guess, I would say it could be the way you hold to cam. Prolly when using liveview, your stance is a litlle bit more steady (less movement).... I'm just guessing here.

 

[daredevil123]

I have send down my lens for calibration once and the technician reset the lens.

If its lens problem, shouldnt the live view be oof as well?

LV and viewfinder uses different AF sensors.

For LV, it will do contrast detection, and that contrast detection is based on the image captured on the sensor. So definitely no problem in LV.

you need to bring your lens and camera into the service center.