Focusing Problem with N1

[se_kp_sg]

BTW, with respect to my first post:

My 50mm f1.4 is faulty. So I sent the lens and the body back to Japan for calibration.

The system is still focussing slight shorter than the correct distance.

My 24-85 is more forgiving of focussing mistake because of its larger f-no.

 

[drmccoy]

Mike and Se,

Thanks very much for your insight. From your comments, other material on the site, and my own very limited experience, what I infer is that if there's an advantage to buying new, it's not necessarily what I was thinking of--i.e. having a more recent s&le in which early bugs have been ironed out or corrected. The advantage, if there is one, may only be the warranty that allows you to send it back to Contax for adjustment or replacement, if necessary. Even then, it seems, that might not necessarily put things completely right. Or so I gather. Thanks again,

Drew

 

[dormant]

Most of AF cameras I've used have shown near focus, focusing slightly in front of the object. I'm talking only about using the central focus point, and I've seen this phenomenon in Canon, Nikon, Minolta and Contax N units. Some may have dead-on AF, but most have a slight near focus.

The reason for this phenomenon, as I've been told, is that, since it is very difficult to manufacture dead-on accurate AF in every unit, the permissible margin of error allows for a slight near focus, because the back focus area is deeper than the front focus area. So when you stop down, it is more likely to have object in focus with near focus than far focus.

Now, I don't know how reliable this explanation is, but it is indeed interesting to find so many near focusing units rather than far focusing ones.

In my case, I never did send any of cameras back to factory to have its AF adjusted, because I could still use it no problem despite the slight near focus, unless the object was very close up...about three feet and less.

Well, I'm a lazy lazy man who'd rather do MF than sending camera back for three weeks.

 

[drmccoy]

I had a chance to play with the demo N1 and 24-85mm at a nearby dealer a couple of days ago. The serial number on the camera was very low, much lower than others I have tried (and presumably manufactured quite early in the production run of N1s), and it focused perfectly at all distances at all focal lengths--i.e. none of the conspicuous "near focusing" I had found on the two used N1's I had worked with in the past (and returned). When I focused with the central sensor on this body at 85mm on a very distant object, the focus ring went to infinity, rather than stop short of it, and the viewfinder image was tack sharp rather than a tad soft. Even taking into account Taylor's point--that most autofocus systems tend to err on the side of near focus (for good reason)--my experience with this N1 confirmed my sense that something was awry with the others. And clearly serial number, or date of production, has little to do with the problem on the N1 when it rears its ugly head. I know it's supposed to be a "dual focus" camera, and like Taylor I had no problem touching up the focus manually when I needed to and had the time; but I still balk at the idea that an expensive camera (that takes the finest lenses I've ever used) can't be relied on to autofocus reasonably accurately without intervention. Maybe I'm asking for too much and should get over it.

 

[johnw]

Does anyone know if the NX has the same focusing quirks/problems as the N1? They supposedly have the same autofocus system. I haven't noticed any problems with my NX, but....

 

[dormant]

The word is that NX has a marginally better, if at all, AF system than that of N1. I personally didn't feel much difference between the two though.

As Drew said, and I concur, any quirk in the AF system is mostly just your luck...or karma point. If you have a dead-on AF unit, you must have done something good in life that the gods of AF look kindly upon you. Date of manufacture doesn't really tell the whole story either, unless there had heen a serious defect that was later resolved after a certain serial number.

The bottom line is, yes, some NX are bound to have near focus. But if yours doesn't, then thank heaven and shoot away. If yours does, send it back to Kyocera and keep at it until you get the dead-on AF. Or, if possible, you can choose to live with it as just another of life's imperfections, as there are so many of those to begin with.

 

[dormant]

It has come to my attention that you can indeed change the internal AF setting of your N1 and NX. There are certain procedures that let you into the "configuration mode" of your camera, and there you can adjust your AF point for near or far focus.

For instance, if you feel that your camera has persistent near or far focus, you can get into this configuration mode and change the parameter value until you hit dead-on with your AF.

Also, if you have a problem with your split not exactly agreeing with your AF, you can change AF to achieve a dead-on focus. (This of course requires that the split has the correct focus.)

Contax of course strongly advises against end users fiddling with the camera's internal setup, and you must do it at your own peril. As this "configuration mode" seems to have many changeable setting parameters beside AF, changing the wrong parameter may cause serious problems.

 

[charlie]

Taylor,

Where we can find you mentioned "configuration mode"? Anyway document could show us how?

 

[dormant]

Charlie,

I should think that the source is the service manual, but I doubt it is available online anywhere.

 

[Contaxcam]

<<I should think that the source is the service manual>>

Taylor, do you have an idea as to where to obtain one of these service manuals? Cheers, Vincent