canon 50 mm f1.4 calibration

david1701

david1701

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David
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Hi all,

Think my new (secondhand) 50mm f1.4 USM is front focussing as I have been focussing in on the eyes and getting eyebrows in focus and eyes not. Is there an empirical test I can do as I have a bit of micro adjustment in camera and may be able to correct it in that...

I can post sample pics in a bit but still in camera and I have to get to dinner before it stops.

Regards,
David
 
just tried it, anyone know a way to do this without a tripod as its freaking the hell out of me

also trying to source a tripod
 
david1701 said:
just tried it, anyone know a way to do this without a tripod as its freaking the hell out of me
Click to expand...

Rest the camera on something else? (e.g. get two chairs, put the laptop on one and the camera on the other. They'll be at sufficiently similar heights to get the lens roughly calibrated)
 
Chill out :)

What sort of range are you shooting at? Remember the focus points in your camera are bigger than the dots through the viewfinder would suggest so it may be you are just focussing on the eyebrow.

To use the focus chart set it up near the edge of a table, then use the edge of a table with your hand firmly over the top of the camera/lens to make sure your camera does not move while pointing it down at the focus chart.
 
RichardtheSane said:
What sort of range are you shooting at? Remember the focus points in your camera are bigger than the dots through the viewfinder would suggest so it may be you are just focussing on the eyebrow.
Click to expand...

I agree with this. Furthermore, if your DOF is so narrow that eyebrows are sharp and eyes not, you also need to consider movement either by yourself or your subject after you've focused. If your DOF is only a few mm then the tiniest wobble by either one of you will cause problems.

With all that said, I do find that front focusing seems to be a common trait amongst most of my 10 Canon lenses, more so with my 1D3 than my 50D, so don't think you got a duff lens, just one working to Canon's usual specs.

You will need to figure out if you have an eyebrow problem rather than poor lens/body calibration and, if you don't, then a normal calibration should suffice. If the camera is picking up the eyebrow unavoidably then you could actually prposely set your AF for back focus so that when you do focus deliberately on an eyebrow it is the eye that is sharp. That will muck things up for more conventional shooting, but it is an option and the approach is actually mentioned in one of Canon's videos about the 1D3 (applies to the 50D as well).

Video - See video chapter 6 - http://cpn.canon-europe.com/content/masterclass/eos_1d_mark_iii.do - it's mentioned about 6 minutes in.
 
cheers guys soo much I am now de stressed, I set it up using a slightly ghetto method and found it was focussing spot on on the eye with +4 (just like if I mf'd it. I also tried the chart and at 0 it is ballpark right, I need to source a tripod from someone then I'dd try it properly but I know it will be within a few and i have up to 20 so I'm in no way worried now :p
 
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