johnf3f said:
bycostello said:
takesome1 said:
johnf3f said:
I have tried all my 9 Canon AF lenses (ranging from 17 to 800mm) and ended up with micro adjustment at or very near 0 on my1D4, they also focus just fine on my other EOS cameras (5Dc, EOS3, EOS 33V and EOS 50E) am I just lucky?
I am not questioning that micro AF adjustment is not a great confidence builder, just saying that I have not found a use for it - except for confidence building!
If you were using a yard stick and duck tape like the OP then yes you are lucky.
;D ;D ;D
Maybe so, but having said that within the small circle of photographers I know well (including 1 pro) none of us have used this facility on any of our lenses to the best of my knowledge. The only Nikon shooter I know well has not needed to use it either. The cameras in question are a 40D, 5Dc and half a dozen 1D Mk4s, lenses are nearly all Canon (mainly L series) from 16mm to 800mm, sorry I can't remember the details of the 2 bodies that our Nikonian friend uses. I have also had no AF accuracy issues with my EOS 3, EOS 33V and EOS 50E - I must be really lucky!
P.S. the only camera I have used the Yardstick method with was my Leica IIIg - still spot on (within 1/2 inch or less at 6 feet) after all these years with all 3 lenses and has never been serviced.
Of course this quote was just a rehash of an earlier post you responded to.
The thing is that the ruler method is not very accurate, it will probably get most people close enough.
Even the other methods like Lens Align and Reiken Focal are only accurate to a certain point.
Both will give you a value at 25x or 50x the distance from the target (or the distance you pick).
You will know what your values are at the light level you use.
With lens align if you just use it once, and do not repeat your tests several times and get the exact same results you will not know if you are getting accurate results.
What you find out if you do enough testing with Lens Align (Not Reiken because it will just fail the test at low light levels) is if you repeat the exact same test and vary the lighting at different levels you will get different results. Do this and you are developing an understanding of how your AF system is performing.
One thing you find is that often a lens can be of +/- quit a few points before you may notice. For instance I have a 300mm f/2.8 IS that is off by +5 on every body I have. Without any adjustment I can get a 80% keeper rate with my 1D IV. Adjust the AFMA it gets about a 97% keeper rate.
I could pick up any of my lenses and put them on my 1D IV or 5D with no adjustments and get a respectable keeper rate. A few of the L lenses I have I can tweak the adjustment a bit and get the keeper rate up.
I find the reason for doing the AFMA is just increasing the keeper rate up by a few percent. It is not correcting a lens that is so far off it doesn't take a decent picture. If a lens is that bad I am shipping it to Canon.