Contax G 90mm lens - metering

[Plyn]

Hello Ladies and Gents

My 90mm seems to have developed a problem on my G! - when the lens is fitted and the shutter button is half pressed as usual the shutter speed appears in the viewfinder, as usual. But if I change the aperture on the lens the shutter speed does not change. I.e. I focus etc at an aperture of f22 and the shutter speed reads 1/35 - but if I then change the aperture to f2 the shutter speed stays at 1/35. It gets stranger - if I put my finger over the external meter the shutter speed will change. So its almost as if the camera is not metering TTL with the 90mm fitted.

I have tried another 90mm lens and the same thing happens. But the camera works fine with my 45mm and 28mm - i.e. the shutter speed changes with aperture.

This is quite bizarre. Has anyone else come across this? Any ideas what the problem might be?

Thanks,

Bill

 

[Socke]

Mine works, so I tried metering without a lens and it does meter through the lensmount. Covering the external meter didn't change anything.

 

[Plyn]

Thanks for your reply Socke - looks like my camera body needs to see the doctor.

Bill

 

[Socke]

Plyn, it can be the lenscontacts! When I put the body cap on the camera doesn't meter at all, it stays at 16".

So the external meter must be activated by one of the lens contacts.

 

[jano]

Plyn, it can be the lenscontacts! When I put the body cap on the camera doesn't meter at all, it stays at 16".

So the external meter must be activated by one of the lens contacts.

I agree he should check the lens contacts.. but you might want to check your logic 😉 What happens if instead of the body cap you leave the lens cap on your lens?

 

[Plyn]

It is a puzzle – if I put the lens cap on the 90mm when it is fitted to the camera, the camera still meters - through the external meter. If I then block the external meter window with my finger the shutter time falls to 16". This also means that if I change the aperture on the lens it does not affect the shutter speed.

I've cleaned the camera contacts as you suggest - but it looks like I have a dodgy contact and the camera is not recognising the 90mm, and so switches automatically to external metering. If I loosen the lens a little on its mount and twist it a fraction as if I was taking it off it then meters TTL normally - so perhaps one of the contacts is not making full contact with the lens- which is strange because the 45mm and 28mm lenses work fine!.

Bill

 

[Socke]

I agree he should check the lens contacts.. but you might want to check your logic 😉 What happens if instead of the body cap you leave the lens cap on your lens?

The same!

I first thought the Contax G switches to external metering when the internal meter is obstructed, so I put a lens cleaning cloth into the mount and tried it. Then I left the lens off and metered with the body cap on.

So I'm pretty sure the metering is switched by the lens contacts and not by obstructing the internal cell.

 

[Socke]

If I loosen the lens a little on its mount and twist it a fraction as if I was taking it off it then meters TTL normally - so perhaps one of the contacts is not making full contact with the lens- which is strange because the 45mm and 28mm lenses work fine!.

Bill

I had some weird focus problems with my 45 once, one of the contacts on the lens was slightly bend and shortend the two contacts to the left of the camera.

 

[Plyn]

Thanks Socke, I'll have a good look at the contacts at the weekend. One of the contacts must switch between external and TTL metering, unless it is done somehow by movement of the cam.

Maybe it will be cheaper to upgrade to a second hand G2 to replace the dud G1 🙂

Bill

 

[jano]

The same!

I first thought the Contax G switches to external metering when the internal meter is obstructed, so I put a lens cleaning cloth into the mount and tried it. Then I left the lens off and metered with the body cap on.

So I'm pretty sure the metering is switched by the lens contacts and not by obstructing the internal cell.

Hmm.. both the G1 and G2 display 16" for me with the lens cap on. I still forget to take the blasted thing off occasionally, heheh -- I'll click the shutter, and then not hear the shutter close and I wait and wait.. look at the front of the camera and :bang: :bang: :bang:

I think your conclusions here are incorrect, but I may be not reading it correctly. Oh, well. Have a nice weekend 🙂