Focusing Problem with N1

se_kp_sg

Member
My 24-85 is dead-on accurate in terms of focussing.

But my 50mm f1.4 and 17-35mm are ALWAYS focusing at a shorter distance than necessary. So, I have to manually turn the focussing ring to the right to achieve sharpness. Very irritating!

Is this inherent again? Or am I getting a faulty N1. I am not keen in sending for repair as god knows what they would do to the insides of the camera, as well as it may come back with some scratches on the body.
 

wolfgang

Active Member
Se, I would send it in, because N1 is supposed to focus precisley, but slowley. Try it!

Regards
Wolfgang
 

se_kp_sg

Member
Thanks Wolfgang.

I have sent my N1 about a month ago to the agent in Singapore, Tithes Marketing. They are taking soooo looong to get it done.

Well, so much for service from Contax and it agents. It had better come back soon. Otherwise, I am going making a hell of racquet.
 
M

mogrkaku

Anyone else face the same problem? I have the same problem with NX and 28-80...very annoying..
 
C

charlie

I am not sure if you guys notice that N1 seems didn't focus well with its 5 auto-focus; I mean the other corner than center position didn't give me the same result when I use wide range side of 24-85.
Is your machine has the same problem?
 

fotografz

Well-Known Member
Charlie, all AF cameras act that way. The center position is always the most sensitive. My Canon EOS 1v and 1Ds act that way, and they are the fastest AF you can get. In fact, most AF sensors will not work at all with lenses who's maximum aperture is above f/5.6, (for ex&le, a f/4 lens with a 2X extender = f/8). One exception to that is some of the Pro level Canon AF cameras, which are so sensitive that you can use a f/8 lens...BUT only if you use the center position.
 
C

charlie

Marc, really appreciate that you made me released from this case. :)
 

drmccoy

New Member
I'm still confused about whether the autofocusing glitches on the N1 that require adjustment or recalibration are less likely to occur in recently manufactured s&les. Is there an advantage to buying new over used, and looking for a high serial number? Or is the problem random, no matter when the camera was made? I've worked on two separate occasions with used N1/24-85mm combos, and both tended to autofocus a bit short of perfect focus at longer distances. Is it the opinion of forum membrs that I would be just as likely to encounter this problem with new s&les of the body and lens? Any insight would be appreciated.
 
M

mikel

Drew,

When I still had my N1, I had sent it together with VS24-85mm to Kyocera for few adjustments. One of the things I wanted fixed was zoom creep and another was a problem with focusing in dim light. At the end, although they did fix the problem with the zoom creep, I insisted they simply give me brand new lens as replacement. So, I got new lens, which had OLDER serial number that mine and it didn't exhibit focusing problems, nor did it have zoom creep.

So, I'm not sure there is a difference between older serial numbers or newer serial numbers. I'm thinking, maybe there was simply a bad batch one day?

Also, just keep in mind. Central sensor is the most accurate, the rest aren't. So, if it focuses short of subject when using any other 4 sensors in difficult situations - it's probably normal.

Mike.
 

se_kp_sg

Member
Hi Drew.

You'd hit the problem right on!

Yes, it seems that the camera/lens ALWAYS focuses shorter than the correct distance.

So, what I normally do is once the lens has stop focussing, I will just turn the focussing ring A LITTLE to the anticlockwise direction (to a slightly longer distance).

Sometimes the slight turn is too slight, but most of the time it works!

Don't expect too much of the Contax focusing compared to the Canons and Nikons.
 

se_kp_sg

Member
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

New Member
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
 
D

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

New Member
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

Member
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....
 
D

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.
 
D

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.
 
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charlie

Taylor,

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

dormant

Charlie,

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

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
 
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