[adwb]

I have a k10d fitted with a katz eye split prism focus screen.
Through the viewfinder with the auto focus on, fitted to a tripod with using time delay actuation, and auto focus single the image in the split screen is always slightly out of line but the focus hexagon is lit up.
.
If I now set the focus on manual and line the lines on the split screen up perfectly again the focus confirmation hex comes on.

If I take two images with an object with a vertical line with a sharp edge so I can clearly see what the screen is showing to aid focusing then the manual image is much sharper when zoomed on the screen on my computer to view that edge.

If there is an an object or foliage behind the vertical line object it will be more in focus with the auto focus than with the manual .

I assume therefore that the k10 is back focusing but why is the focus confirmation coming on for both manual and auto when there is a difference in the focus ring setting?

Is possible the katz eye is effecting the focus? I thought the focus screen had no effect on the auto focus?

Finally I should mention this difference in the viewed focus via the split prism and the aforementioned focus results are the same with any lens I try.

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Last edited by adwb; 05-14-2012 at 10:14 AM.

[sterretje]

I assume therefore that the k10 is back focusing but why is the focus confirmation coming on for both manual and auto when there is a difference in the focus ring setting?

The autofocus hexagon 'covers' a small range; it is therefore not as accurate as the split prism.

Is possible the katz eye is effecting the focus? I thought the focus screen had no effect on the auto focus?

It indeed does not affect the AF; the AF sensor is in the bottom of the camera.

With regards to the foliage: I assume you're focusing on the foliage and not on the straight subject in front of it. Do you use the split prism or the microprism collar as the focusing aid in MF?

[bobpur]

Those are two completely independent adjustments, don't mix them together for setting up.
First ignore the split screen and using the Debug method and the center spot adjust your AF system, then if the split
does not agree or is not sharp adjust the focus screen using shims.
I used an aluminum tape on only the sides of the screen just around 1/16 " ( it took 3 layers ) to get the manual focus spot on.
As there is a bit of " play " in the AF system use the same direction to adjust them Eg. from Infinity to close or close up then the target.
If you turn the lens one way for AF and the other for manual to setup they probably won't be synced.
It takes a bit of work but can be done. Makes it a lot easier to use and only has to be done once.

[adwb]

The autofocus hexagon 'covers' a small range; it is therefore not as accurate as the split prism.

With regards to the foliage: I assume you're focusing on the foliage and not on the straight subject in front of it. Do you use the split prism or the microprism collar as the focusing aid in MF?

I am using the split with single centre spot on the object previously described.
when focused with the split screen not in line the background is softer than when I focus manually and get the object in line in the split prism view.

[adwb]

Those are two completely independent adjustments, don't mix them together for setting up.
First ignore the split screen and using the Debug method and the center spot adjust your AF system, then if the split
does not agree or is not sharp adjust the focus screen using shims.
I used an aluminum tape on only the sides of the screen just around 1/16 " ( it took 3 layers ) to get the manual focus spot on.
As there is a bit of " play " in the AF system use the same direction to adjust them Eg. from Infinity to close or close up then the target.
If you turn the lens one way for AF and the other for manual to setup they probably won't be synced.
It takes a bit of work but can be done. Makes it a lot easier to use and only has to be done once.

Thank you I understand and assume that since I have to manually adjust fictionally from the auto focus position that the camera is out and needs adjusting via the debug mode

I once got into the debug mode on this camera long ago, can you point me to a thread that will tell me how to get in and out of this mode as I have forgotten how to do it.?

[bobpur]

Debug mode