Back Focus

[eason]

Hi,what is back focus?Could anybody explain?

 

[EOS20D]

when u focus on a subject it is suppose to turn up sharp. however, if the subject's background turn out to be sharp, it means u have a backfocus.

 

[erictan8888]

just like to share:

i was taught how to check back focus by a nikon staff at the recent sitex....
very helpful person, wear spects one.... and another nice nikon guy, a bit curly hair one...

anyway, they told me to check back focus, take a ruler, then focus at, say the 5cm mark and shoot the photo. then view the photo, and if the 5cm mark in the pic is in focus, then camera ok. but if the 5 cm mark is not in focus, then you have a back focus issue.... got to send to agent for calibration....

hope that helps...

 

[Del_CtrlnoAlt]

just like to share:

i was taught how to check back focus by a nikon staff at the recent sitex....
very helpful person, wear spects one.... and another nice nikon guy, a bit curly hair one...

anyway, they told me to check back focus, take a ruler, then focus at, say the 5cm mark and shoot the photo. then view the photo, and if the 5cm mark in the pic is in focus, then camera ok. but if the 5 cm mark is not in focus, then you have a back focus issue.... got to send to agent for calibration....

hope that helps...

hmm... so what shutter speed & aperture to use? should use flash?

 

[EOS20D]

just set your aperture to the largest, 1/60s, focus the "5" cm on the ruler and shoot with flash. if the sharpness falls on 6 and above, u might have a back focus issue. btw, shoot at an angle ~30 degrees in the direction of 1,2,3cm....