(and, yes, I was on single-area AF)

It's frustrating, but not the end of the world, I guess -- just will have to go back to film (or P&S) while my baby's in the shop.

-Gian

Just to double-check since you didn't say exactly.
You're not only on single-area AF but also are sure the center area is selected?

Bill

Visit me, info and galleries at: http://home.comcast.net/~NikonD70

Not to confuse matters, but i found that the actual focus sensors on mine are positioned to the upper left corner of the central focus brackets on the viewfinder. It doesn't make a huge difference, but when shooting at angled subjects the impression would be that i had slight back focus (if the subject was angled sloping upwards away from the camera).

I determined that my focus was spot-on by shooting at flat objects and viewing them at 100%.

Guy

Regarding the upper-left placement of the actual sensor within the brackets, I'll have to shoot a flat target and see if that makes a difference -- there's a (very real) possibility taht I'm being too picky and blaming technique / subject shifting issues on the camera!

I heard that the backfocus issues were more prevalent with earlier serial numbers -- any reason to believe that Nikon changed something in later runs?

-Gian

Yes, it's true that the focus areas as shown in the viewfinder can differ in any direction from the areas actually used; your mileage may vary

In my shot the large '8' to the left of the red dot was in the "center".
So my sensor seems to be slightly to the right of where you might expect.

Gian, try a shot similar to mine.
Use the built-in flash if necessary to shorten the exposure.
Take note of where you think the center is.
When you load the image you can locate the actual center.
They should be pretty close together.

The distances you initially reported were large enough that I suspected the wrong AF sensor was used rather than just a slightly shifted sensor.
But you say it is the correct sensor.

BTW, were you testing backfocus because you had images that came out wrong?

FWIW, whether there was ever a batch of cameras with backfocus problems is immaterial.
Either your camera is OK or it is not.

Bill

Visit me, info and galleries at: http://home.comcast.net/~NikonD70

In my shots, fully 1/2" of ruler fell between the brackets (the ruler was angled 45 degrees away from the camera). On each shot, the bottom bracket was not sharp, but the area beneath the top bracket was dead-on. It appeared that about 2/3 of the DOF fell above the top focus bracket vs. the 1/2 I expected, but now we're getting into minutia.

Lesson learned -- When using the center focus sensor, align the top bracket with the actual focus point.

Thanks to all.

-Gian

P.S. I'm upgrading my membership right away -- only a fraction of the value I've gleaned from this fab site!

Great!
FWIW, here is a 260x194 crop of the image in #3.
This is approximately the size of the center sensor in the viewfinder.

My viewfinder and sensor seem very close.
As you and Guy have shown, your mileage may vary

Bill

Visit me, info and galleries at: http://home.comcast.net/~NikonD70

FWIW, on my D70, I seem to get a number of front-focus issues on my 50mm @ f1.8 at close range. Often when I take closeish pics of my dog (but outside min focus distance), focusing on the eyes, her nose seems in better focus than the eyes, which look soft. Whereas my 80-210 seems SLIGHTLY backfocused in that the focus point is reasonably sharp, but anything right in front is OOF and the depth of field extends further back than I would expect. Its weird, seems to be different situations with different lenses.