Back focus - camera or lens calibration needed?

[JohnJon82]

Hi all,

Was trying out my camera yesterday with a friend. He noticed this thing: My camera has a back focus problem with his lens, which does not have this problem on his camera. Then I switch to my lens (50mm 1.8) on my camera, and noticed the same thing. I shoot very close at 45 degree to a poster, the letters in front of the letter I focus is sharp, but not the one I focus. Went home, tried with other 2 zooms I have but the back focus is less noticeable (probably due to the aperture, can only go to f4 compared to f1.8 of the 50mm). He shoot macro so he can notice this problem. I shoot general things and never paid attention to it, sometime when photo not sharp, I will think is my hand or skill :bsmilie: Probably can get it re-calibrated by CSC since all the lenses and camera are still under warranty. I am reading how to do a more scientific mis-focus test chart from the internet and will try later.

Calibration is done to the camera body or to the lens? Asking this because, if to the lens, mean every lens I have to ask them to calibrate? And when I buy new lens or sell the camera, I or the buyer have to redo this process again? Thanks!

 

[mds80]

Not too familiar with the Canon 600D, does it have any micro-adjustment settings? Try changing these settings if they are available.

 

[eleveninth]

they will ask you to put body and lens with them anyway.

 

[daredevil123]

If all lenses appear back focused on your camera, you need to send your camera body in for adjustment.

 

[daredevil123]

Not too familiar with the Canon 600D, does it have any micro-adjustment settings? Try changing these settings if they are available.

micro adjustment is good if only one lens is back or front focusing.

 

[JohnJon82]

Thanks all for reply!

600D don't have any micro adjustment settings. Just tested with the focus test chart download from internet with tripod and cable release for more controlled test . My 3 lens all show front focus, one weird thing is the 24-105 shows 2 back focus out of 10 photo I taken though... Miss focus about 2-4mm, later shoot macro, focus on the eyes, but end up tummy very sharp. Learnt new thing today...

Will go down to CSC on Monday. So they will adjust the body instead of the lens? Need to bring down all my lens for them?

 

[tecnica]

usually, calibration is done on the lens, meaning to say adjust the lens to fit the body.

if the body is tweaked, it will affect the focus of all the other lenses as well. unless the body can be programmed to accept different adjustments for different lenses as in the microadjustment function?

 

[Octarine]

Something to consider when hunting for 'perfect focus':
https://www.lensrentals.com/blog/2011/10/the-limits-of-variation
https://www.lensrentals.com/blog/2011/10/notes-on-lens-and-camera-variation