Lenses on mirrorless body need Focus calibration ?

neilt3 wrote:

Photato wrote:

neilt3 wrote:

Is that an EF mount lens your using on an R body via an adapter?

It is a third party adapter Ykeasu, which has worked well with a Tokina EF lens, or other Canon EF lenses, no AF issues.

I'm using Canon EF lenses on E mount cameras with a Sigma MC-11 adapter with no problems.

Apart from a Sigma 15-30mm lens , all my EF lenses are Canon , mostly "L" lenses .

I did have a Commlite adapter that I used on a NEX 7 , but this doesn't work well with my a7Riv or a6600 .

Some lens/camera/adapter combinations don't always work well together.

If so , which adapter?

You sometimes find using lenses via an adapter perform much better in AF-C mode than AF-S .

Did not know. But AF-C fdpepletes the battery faster and takes a toll on the focus motors over time when no needed.

Not really .

AF only functions while you press the shutter button to obtain focus

Perhaps on  Sony, but not on a Canon.

I suspect that you are thinking that AF-C is referring to what Canon calls Servo AF, when the camera continues focusing as long as you hold the button down.

In Canon world, AF-C is Continuous AF where the camera will continue trying to focus when it is sitting on a table with no-one touching it (or hanging around your neck). The theory behind this is that the lens is always very close to being focused when you touch the shutter (or back button focus) to take a shot. It does, however, mean that the camera is focusing almost continuously (as long as the camera is turned on) and does consume more battery doing so.

, when your focussed , you take the picture . When your not wanting to focus on anything, you take your finger off the shutter release and to camera stops using the AF motors .

You don't really wear the motors out any more as your using them the same amount to obtain focus .

See above.

Your only adding unnecessary wear if your holding the shutter button half way down when your not tracking anything.

If you are tracking something, then the camera needs to be set to AF-C anyway.

See above.

Otherwise you'll lock focus somewhere other than what your shooting.

If you want to prefocus on a point while you wait for the subject to be there ( sports , racing etc ) then you can prefocus in whichever mode works best .

Also , is the lens focussing with the aperture wide open , then stopping down on exposure?

If so , there could be some focus shift .

But that is how AF is supposed to work, it opens up temporarily then return to the set aperture when taking the shot, the focus plane should not change.

Do a search on "focus shift" . Some lenses suffer more from it than others .

Yes that's how DSLRs work , but most mirror less cameras focus with the lens stopped down with native lenses so you should have 100% accurate focus every time , preventing focus shift .

When adapting lenses , they mostly seem to focus wide open , then stop down after AF is locked , before taking the image .

Try taking some shots wide open with a stationary target ( a wall for eg ) and see how it behaves .

Then do the same shot stopped down , and see it behaves differently.