Ronald M
Veteran
There are lots of issues with manual focus and they present major problems for Nikon and for Katz.
Previous communications I have had with Rachel indicate they sized the "billet" or blank form for DX or perhaps a D700 with is a 95% screen. They can not make a full 100% 24x36 mm screen from the blanks . Replacing the billet is not economically feasible because of low volume sales.
Based on previous knowledge, the angle of the split prism is set for 5.6 or 2.8 lenses, I do not remember which. This was the proper decision when cameras used slower lenses, but now we are trying to use 1.4 and the accuracy is not sufficient.
If the angle is changed to optimize 1.4, then we get the dreaded half black split.
Back in the day, Nikon furnished different screens for for different speed lenses and they were field interchangeable. The frame precision required in manufacturing the camera was very high as was the screen/frame assembly. I believe no adjustment was possible. The camera was right or wrong. On todays consumer grade cameras, the screen is adjusted by shims to raise and lower to get it in the proper position.
On the better cameras, D200, D800, D3, there is a nice handy hex screw to accomplish the same thing.
Years back, screen position was never perfect and when the Katz screen was installed, perfect focus still could not be achieved unless it could be fine tuned with shims or hex. Katz provided this service, or if you were not fumble fingered they would get you the Nikon part numbers
for the shims. It was trial and error to remove and replace shims and dirt/damage easily resulted. I would not do it, so my 7000 remains Katzless.
I have no idea how the Df is constructed, shims or hex, or if it is 100% view at .7 magnification which disqualifies a Katz, but they need to speak for themselves on that.
Adding the split prism also compromises certain metering functions that rely heavily on the center area.
So it is not that Nikon hates manual focus, it is that the whole camera needs to be redesigned to accommodate it. They certainly know how, but the world has gone AF. Cost would escalate considerably.
I will say if the screen height is adjusted properly, Auto focus, green dot, and visual on the screen can all be made to agree as I have done it to several cameras, but not one that requires shim replacement. The shims are less than paper thin and require careful handling and without a supply of replacements, I would not do it.
I just checked the F2 and there is no screen height adjustment. only a stop adjustment for the mirror. You can fiddle with it, but it throws the picture off in an attempt to repair focus.
Previous communications I have had with Rachel indicate they sized the "billet" or blank form for DX or perhaps a D700 with is a 95% screen. They can not make a full 100% 24x36 mm screen from the blanks . Replacing the billet is not economically feasible because of low volume sales.
Based on previous knowledge, the angle of the split prism is set for 5.6 or 2.8 lenses, I do not remember which. This was the proper decision when cameras used slower lenses, but now we are trying to use 1.4 and the accuracy is not sufficient.
If the angle is changed to optimize 1.4, then we get the dreaded half black split.
Back in the day, Nikon furnished different screens for for different speed lenses and they were field interchangeable. The frame precision required in manufacturing the camera was very high as was the screen/frame assembly. I believe no adjustment was possible. The camera was right or wrong. On todays consumer grade cameras, the screen is adjusted by shims to raise and lower to get it in the proper position.
On the better cameras, D200, D800, D3, there is a nice handy hex screw to accomplish the same thing.
Years back, screen position was never perfect and when the Katz screen was installed, perfect focus still could not be achieved unless it could be fine tuned with shims or hex. Katz provided this service, or if you were not fumble fingered they would get you the Nikon part numbers
for the shims. It was trial and error to remove and replace shims and dirt/damage easily resulted. I would not do it, so my 7000 remains Katzless.
I have no idea how the Df is constructed, shims or hex, or if it is 100% view at .7 magnification which disqualifies a Katz, but they need to speak for themselves on that.
Adding the split prism also compromises certain metering functions that rely heavily on the center area.
So it is not that Nikon hates manual focus, it is that the whole camera needs to be redesigned to accommodate it. They certainly know how, but the world has gone AF. Cost would escalate considerably.
I will say if the screen height is adjusted properly, Auto focus, green dot, and visual on the screen can all be made to agree as I have done it to several cameras, but not one that requires shim replacement. The shims are less than paper thin and require careful handling and without a supply of replacements, I would not do it.
I just checked the F2 and there is no screen height adjustment. only a stop adjustment for the mirror. You can fiddle with it, but it throws the picture off in an attempt to repair focus.
