# Canon and lens calibration



## NWPhil (Mar 8, 2012)

How come Canon does allow for lens calibration in some camera models, and yet does not supply any sort of software or technicalsupport for such?
Do they rather have people keep on sending lenses back and forth with those silly complaints about being not sharp/focusing well, etc?
Why are they letting others make money out of something they could easly provide for a small fee? - actually should be free, or with a simpler free version available

Does not make sense to me.
Yes, I like the fact I can micro-adjust focus of a specific lens to a specific camera - I don't like that Canon does not provide any help or support for it.
Shame on you Canon


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## Mt Spokane Photography (Mar 8, 2012)

NWPhil said:


> How come Canon does allow for lens calibration in some camera models, and yet does not supply any sort of software or technicalsupport for such?
> Do they rather have people keep on sending lenses back and forth with those silly complaints about being not sharp/focusing well, etc?
> Why are they letting others make money out of something they could easly provide for a small fee? - actually should be free, or with a simpler free version available
> 
> ...



Try out the FoCal software. Then you might get a hint as to why Canon does not provide something like it. It demonstrates clearly the variability of autofocus on a camera and lens combination, and in particular, the autofocus issues at close versus far distances, and with low end lenses. It seems to be more of a lens property.

It would have less experienced users screaming that their cameras and lenses were broken, when AF variability is a fact of life. Even though I was aware of the variability, when I started seeing the data that FoCal provides, it was a eye opener.

However, if you look at the shape of the AF bell curves, once you set the AFMA to the best value for the focal length and distance you use, a few points of AFMA off the perfect setting might not have much effect. 

Its pretty clear that AF systems are still not as precise as we'd like. I think we need to see digital lens focus position sensors rather than some wipers on a 1 inch strip of carbon resistor. I would think that a chip in the lens would be able to handle a digital position signal, its just that the carbon sliders are so cheap to make.

A digital lens should be able to go to the exact point commanded by the camera body, Of course, there will always be error from mechanical friction and other causes, but its possible to be much more accurate. Right now, the final position varies depending on the initial lens focus position.


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