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Any known Problems WIth Focusing a 28mm Zeiss Biogon Lens

G

Guest

The autofocus on my 28mm Biogen appears to be extreemly inaccurate. The camera will fire off in SAF when the camera is less than a half metere way from a subject. THe lens is brand new, although that means nothing and that is why we have warranties. Am I doing something wrong?
 
G

Guest

Your lens and body aren't communicating correctly, and the camera is firing without focusing.

Watch the lens to see whether it moves from park while you press the focus button. My guess is that it isn't, even though you hear the focus motor whir. Try switching the camera off and removing and remounting the lens. Several repetitions may clear up the problem. Also, *carefully* clean the camera and lens contacts.

I have a 45 that exhibits this problem intermittantly on my G2. None of my other lenses does. Two trips to Contax USA (lens and body) have failed to correct the problem. I have to test the 45 each time I mount it to ensure it's operating correctly. It's maddening, and I suspect it's an intermittant electrical problem in the lens itself.

--Rick
 
G

Guest

What kills me is that you purchase something brand new expecting it to work and then this happens. I cleaned the camera contacs and also the lens contacts. When I place my hand 12 inches from the lens, the camera tells me I'm focused at 1 meter away. I just picked this lens up as part of a lens kit from B&H. I'm retuning it to them.
 
G

Guest

> Hi, Before you send the lens back, try focusing a little further away. I don't have a 28, but I don't think it will focus as close as 12 inches. Check Page 92 of the camera manual: "If the mark (focus indicator square) blinks on the right side of the Focusing Indicator, the shutter does not trip when the dirve moe is set to "SAF" because your subject is too close to the camera. However, when the drive motor is set at "CAF", the shutter trips although the subject is not sharply focused." IN ENGLISH: In "Single Auto Focus" the shutter will not fire if the lens is not in focus. But, in "Continuous Auto Focus" the shutter will fire even if the subject is out of focus.

Sending stuff back to B&H is a pain. They take forever and you have to hound them to death. Their after-sales support sucks. If you do have a problem and your equipment is under warranty, you much better off sending it to Contax in New Jersey, or elsewhere. I have found their service to be excellent, courteous and fast. Good luck. Art P.
 
G

Guest

I wish I had the manual to the camera. But the problem is that the lens will fire unfocused in SAF with this lens. B&H sucks in general. But I 'm not getting into that. I was forced to purchase this kit because no one else had it. I'm more of an Adorama or Focus Camera person. The guys in Adorama and Focus are much nicer.

Going back to B&H is not a problem. I live in NYC.
 
G

Guest

Listen to this! The problem is now happening with the 45 mm lens too! But it does not happen at all with my 35-70 zoom. What do you think? This is bothering the living <font color="ff0000">•<font color="ff0000">•<font color="ff0000">•<font color="ff0000">•<font color="ff0000">•<font color="ff0000">•<font color="ff0000">•<font color="ff0000">• of me! I don't like to spned this kind of cash for problems.
 
G

Guest

For what it is worth all my prime 'G' lenses (28 / 35 / 45 / 90)will allow the camera to fire even if the subject is closer than the minimum focus distance. And there is no indication in the viewfinder that the focus is inappropriate.

I have not tried it with the zoom yet, but I personally believe that it is an oversight in the programing of the camera, not a fault with the lens.

Clive
 
G

Guest

It's possible we're talking about two or even three separate problems here:

a. Camera firing in SAF mode w/o achieving correct focus (which manual says isnt' possible)
b. Camera readout indicating incorrect focus distance
c. Camera not coupling with lens focusing mechanism

My (intermittant) problem, with the G2+45 only, is a combination of a. and c. It has never happened with any of my other lenses, nor with a camera-store 45. And Contax USA hasn't managed to fix it.

BTW, this problem is how I discovered that the G lenses don't park at infinity.

--Rick
 
G

Guest

It appears that I have a similar problem but with my G1 using the 90mm lens. When I change to the 90, sometimes it won't focus or fire - I just see the two flashing LCDs in the finder, indicating it can't focus. So, I unlock the lens, re-seat it, and it is then usually fine. I also occasionally use a sort of 'pencil' made of fiberglass strands to clean the contacts. This seems to help. It's something I've learned to live with, although I should probably have the lens checked at Kyocera (I live near Tokyo), since the problem DOES NOT occur when I use my Planar 35 (which I love, by the way; what a versatile lens!).
 
O

ojingoh

Member
the same issue happened to me viz the 45mm lens -- i was shooting that way for 2 years! i avoided my g2 b/c of 'focusing problems' until i sent the camera to kyocera in new jersey. all is good now.
 
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