cputeq wrote:
Completely untrue for me, in both my NEX-5N and A77 experience with MF glass. I loved it when it worked, but I'd often be off by a couple of mm.
It wasn't a vision thing either - it's just the focus peaking wasn't that accurate. Even on close targets and 1.4 speed lenses, I'd have a "DOF" of around 4 inches (according to peaking).
I think, at least for me, I'm MORE accurate if I just disable the peaking and eyeball the focus
That's too bad, its taken some practice, but its worked very well for me, although I rarely need to shoot faster than f//2.
AF focus errors are as much a part of a lens as the camera body, in my opinion, its more of a lens error.
I did a AFMA on my 15 Canon lenses using FoCal and right away noted the AF errors on some lenses were much higher than on others. Then I tried my 7D and found the same lenses had the higer rate of AF errors, and one or two had exceptionally high AF errors.
When I got my 5D MK III, it was the same story.
It might be interesting to see a manual run of focal with his settings versus the default FoCal settings to see the difference, if any.
timbop wrote:
This likely accounts for 90% of your improvement in keepers. It's also not a secret :-)
Actually I never used anything but the center point focus since I got it. So that was not a factor on the improvement I wrote about as I was still loosing 5% or more of my images to focus errors.
I shot close to 30,000 images on my 5D and 60,000 images on my current 5D2.
Seventy-five percent of all those images consisted of portraits. That is where I could actually notice the focus errors, as I always focus on eyelashes. Believe me, even at f4 there is shallow DOF.
So I ended up with random front and back focus errors on both cameras UNTIL I changed my settings and technique as shown in my OP.
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scalesusa wrote:
AF focus errors are as much a part of a lens as the camera body, in my opinion, its more of a lens error.
It might be interesting to see a manual run of focal with his settings versus the default FoCal settings to see the difference, if any.
I agree, both the lens and the camera seem to be involved. What I've seen is only the newer lenses on the newer cameras are more accurate.
I put up one example in Part 1 with a 50 f/1.2 before and after MF adjustment. It improves the average AF result greatly when a lens front or backfocuses, but it can't change the shot-to-shot variation.
