G2 Af problems

K

klemcg

Hi!
I have shot a roll of newspaper attached against wall testing AF of G2 with 28,45,90 all fully open (on a tripod of-course). Neither of shots very accurately in focus. Best performer was 90, when 28 and 45 were disastrous (not even close of being in focus). G2 and each lens were bought separately and never calibrated. Did anybody have similar problems? Would sending the camera and the lenses to Kyocera help?
 
F

fastfashn

Calibrated? You don't "calibrate" the lenses and the camera together, there isn't any need.

How far was the paper from the camera, and DID YOU CHECK manual focus or the distance readout in the G2 displays and see whether they correlated to an actual physical measurement with a tape?

Did you try a higher contast image that a newspaper? What was the F-stop used?

-Dana

"Posted by klemen gabrijelcic on Monday, June 30, 2003 - 7:56 pm:

Hi! I have shot a roll of newspaper attached against wall testing AF of G2 with 28,45,90 all fully open (on a tripod of-course). Neither of shots very accurately in focus. Best performer was 90, when 28 and 45 were disastrous (not even close of being in focus). G2 and each lens were bought separately and never calibrated. Did anybody have similar problems? Would sending the camera and the lenses to Kyocera help?"
 
K

klemcg

> Calibrated? You don't "calibrate" the lenses and the camera together, there isn't any need

I am not sure that is true. My N1 AF with 24-85 was performing better after calibration.

I took shots from about 0.6m, 2.5m and 5 m. I did not check the distance with a tape, but the distance readings from the camera were always the same. The newspaper was actually a magazine with large black and white rectangular shapes.
 
F

fastfashn

Check the distance with the tape and see if it agrees with the digital display.

"I did not check the distance with a tape, but the distance readings from the camera were always the same."
 

smartrav

Well-Known Member
> I had this problem with my G-1 and sent it to Contax and they repaired it. They only needed one lens.

Tests I ran: I put a yardstick on a upside garbage can and cereal box with detailed printing on it at the 18 inch point. Yardstick was running away from the camera which was placed on a tripod at 2.5 meters from the 18 inch focus point. I then exposed wide open, mid and smallest aperture. I found the range finder would focus correctly but the lens would move (change focus) when I pushed the shutter. I did this for all lenses. Both for AF and manual. Obviously the worse case was at wide open aperture where DOF is most critical. Fortunately I had a USA warrenty and the camera was fixed at no charge.

I repeated this test with my G-2 and found focusing is perfect (except the 90mm focuses an inch closer than aim at 5 feet. Big deal.) But the reason I got the G-2 was to improve the focus uncertainty issues I was having with th G-1. I use my G-2 mostly in manual mode because I use the camera more like a view camera. Always on a tripod and frequently focusing on some completely apart from the center.

Dave
 

albert4321

Well-Known Member
I remember sometimes ago a member posted a site describe in great details why all AF cameras, including F5 and EOS1 as tested, are not as accurate as true MF camera.

klemen, did you send in both the N1 body and lens to have Contax to "calibrate"? If it did fix the AF problem in N1, it would not be a bad idea to send in your G2 system to do the same.
 

rak996

Member
Help, I just shot my first roll with my new G2 and I was underwelmed. The pictures are worst than my wife's Leica minilux zoom point and shoot. After reading all of your posts about the zeiss lense quality I can only surmise that I am doing something wrong. The people in the pictures are simply not in focus and in some case are blurry. The indoor flash shots are either over or under exposed. I have been using a Nikon f100 previously and selected the Contax over a Leica M7 I hope I did not make a mistake. I would appreciate any helpful suggestions. I read all of your posts and thats what helped me make the Contax Leica decision. Thank You in advance.
 
M

mmermag

Although I am also new to the G system, I can tell you that this camera does not do any 'thinking' for you. Just because there are people in the picture doesn't mean the AF will lock onto them. It may lock onto the wall behind the people. If you want the people to be in focus, you must carefully choose the object you want to be in focus and then lock the focus by depressing the shutter button halfway. Then recompose your view and take to photo. I imagine that this will also effect the flash exposure. If the camera is focussing on the wall 5-10 feet behind the people, then it will expose the wall correctly and not the people. You may have to do some exposure compensation anyway to be sure it comes out the way you want it.

You can always double check if the AF is tracking your subject by looking at the distance gauge inside the finder. See if the distance shown in the finder is about the same as you subject is from you.

Hope this helps.

Mike
 

hdfuhrman

Active Member
Richard,
I agree with Michael. I have no problem with focus other than operator error. Center your subject, depress and hold the focus lock, then recompose your photo and take your picture. My photos are generally in perfect focus, unless I mess up.

Good luck.

Howard
 
U

usa_tarou2000

Hi RICHARD

Did you check out the following things? If there are no problem, you should send your G2 to your camera shop. (1) Is Forcus selecter on the back in SAF (or CAF)? (2) Does Distance indicator on the top of G2 indicate correct distance when you lock the focus using AF lock button on the back? (3) Does your Flash support TTL mode of Kyocera/CONTAX?
 

jhslater

Member
Richard -

I agree with Michael and Howard. Most of the out-of-focus pictures taken with autofacus cameras are operator error. The G2 has a very well defined autofocus window (the small frame in the finder). You need to have a vertical line for horizontal photos or horizontal line for vertical photos splitting the AF frame. There must be enough contrast for the AF system to react. Try another roll of film and carefully select a part of the subject on which to focus. As lon as there is a "line" differentiating parts of the subject, you should get good AF. By holding the shutter release you will lock in the AF results. Then compose and shoot.

Jim
 

robgo2

Active Member
Richard,

The most common reason for mis-focusing with the G2 is failing to realize that if you lift your finger from the shutter button after locking focus, the camera will revert to infinity focus. You must then re-lock focus on your subject before releasing the shutter. This is a quirk of the G focusing system that takes some time to get used to. It is certainly different from your F100, in which the lens stays in focus even after you lift your finger from the shutter button. Once you adapt to the G2, you will find that the process becomes entirely automatic, and you will get the brilliant images that you seek.

Re flash problems, understand that the G's flash and metering systems are far less sophisticated than the F100's, and it tends to overexpose. My solution is simply to set exposure compensation to -1 whenever using the flash. (Fill-flash is an entirely different issue.) Like the Ms, the Gs are mainly used for available light photography, but with a little practice, they can function quite well with a flash.

Have fun with your G2. If you are like many of the members of this forum, your SLR will henceforth get very little use. My N90s hasn't been off the shelf in over two years.

Rob
 

yogi

Well-Known Member
One more note from a fellow user who uses both an F100 and the G2. On the F100 in single focus mode there is a "closest" priority working if there are more multiple objects ad differing distances withing the AF focus brackets. With the G2 you have to have the object fill the entire AF frame. Otherwise it will almost always focus onto the object behind. So for ex&le when I take a facial portrait with the F100 the AF area bracket may only cover half the face and I can confidently be sure that it focused properly through the view finder with closest priority focusing. With the G2, it must be focused completely on the persons face and then recomposed to get the same shot. This is what makes close focusing so difficult on the G2.

I made a small diffucer for my TLA-200 flash using the semi-transparent film cannister from the Fuji Velvia ;) works great. No need to dial-in any compensation and the flash output is softened so a lot less harsh shadows. I got the idea from a fellow member.
 

yogi

Well-Known Member
One more note - on a different list there has been reports of AF error on the G2 that got repaired by Contax. But this was pretty rare. Most of the reporst were with the G1 not the G2.
 
R

robinadshead

> Almon is right - the transparent diffuser is the easy way to go. I got the > tip off this forum too. The other way to crack the overexposed problem is to > leave the TLA 200 permanently on the 28mm setting. By the time you use the > 90mm, the fill is really quite accurate, more so if you combine both the > diffuser and the 28mm position.

Albest, Robin
 

evb

New Member
Once more on G2 + 90mm

Quite a while after the last post in this thread... :) But maybe someone is still here, eh? :)

I'm interested especially in the accuracy of the pair G2 and Sonnar 90. It seems to me that both other my lenses (28 & 45 as well as 35 which I sold) focus correctly while 90 sometimes is completely out of focus, or gives a little blurry pictures. Of course I understand the danger of longer focus length, so use fast film (ISO 800) and shorter exposure time.
 

aposmaragos

New Member
I've recently purchased a G2 with 28mm 45mm and 90mm lenses. All my photos taken with the 90mm are out of focus...Is there anything i can do about it? Please help.
 

evb

New Member
I've recently purchased a G2 with 28mm 45mm and 90mm lenses. All my photos taken with the 90mm are out of focus...Is there anything i can do about it? Please help.
Ah, I see you have the same problem. Seems, this problem is quite usual with the G-system. :(
 

aposmaragos

New Member
So... that means that this is not a problem of the particular lense i own. It's a general problem and thus i can do nothing about it...it's not a matter of calibration or something like that...(although i noticed that my lense always focuses a few cm closer than desired)
I'll keep on searching for a solutionand and i'll let you know if i have an answer. Please let me know if ever you have a solution on this problem.
 

evb

New Member
Thanks.

Some time ago I've read that there was a problem with the 90mm Sonnar but it was usually solved by Contax. The camera and the lens were sent to Contax and it made calibration. At present it seems there is no solution.

I have some sharp or almost sharp photos made with the Sonnar - most of them made at f/4 and f/5.6. So, the lens is better than nothing but it isn't what I expected of it.
 
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