Contax IIa shutter speed dial sensitive

[shawn]

I just picked up a IIa that is in beautiful condition and was said to be CLA. Shutter is firing at all speeds and it seems to be accurate from 1/100 and lower. The 1/250 speed setting is very sensitive to dial position. If it is at 1/250 or slightly closer to 1/100 it seems like the shutter speed is about 1/25 of a second. If the dial is a little past 1/250 the shutter speed is much closer sounding to where it should be.

I assume this isn't typical. Any thoughts what could be the cause?

Thanks,

Shawn

 

[Pioneer]

Neither of mine have this problem. Once set to 1/250 the shutter should lock in with very little play. Certainly not enough to cause the shutter speeds to drift the way you are describing.

 

[shawn]

Thanks, my shutter speed dial doesn't really lock into any setting. It turns easily without lifting it up so it is easy for the 1/250 setting to be firing wrong.

Shawn

 

[Gregm61]

To be honest, there's no telling what else is wrong with it. Hopefully you were given some sort of return policy. Otherwise, you've probably been taken.

 

[popavvakum]

Thanks, my shutter speed dial doesn't really lock into any setting. It turns easily without lifting it up so it is easy for the 1/250 setting to be firing wrong.

Shawn

This is certainly not normal and it may be caused by a number of things the most innocent of which would be trying to wind a frame when the shutter was open on B position. Are the colour dots on the shutter disk and button aligned? Does it fire normally at B?

 

[johank]

Some parts seems to lack since your settings floats. On my II and IIa they have definitive positions. You have got a sick IIa.

 

[shawn]

This is certainly not normal and it may be caused by a number of things the most innocent of which would be trying to wind a frame when the shutter was open on B position. Are the colour dots on the shutter disk and button aligned? Does it fire normally at B?

I am not sure what you mean about the color dots on the shutter disk? This is a black dial model. The B setting works perfectly and the slow speeds (1 through 1/100) are within a 1/3 of a stop accurate per Shutter-Speed. Above that it is tougher to measure except for the 1/250 when it is firing slow.

Thanks,

Shawn

 

[shawn]

Some parts seems to lack since your settings floats. On my II and IIa they have definitive positions. You have got a sick IIa.

I think I may pull the cover just to see if anything is missing from the shutter speed dial.

This site http://rick_oleson.tripod.com/index-95.html gives a decent exploded view of all the parts.

Thanks,

Shawn

 

[sevo]

The times are hard slotted - there should be no way to set an intermediate.

 

[Steve Bellayr]

The Contax system is very delicate. Buying one off the internet is risky, especially if the prices run into the hundreds. More than like the camera will need an overhaul and there is only one person who does that work and he is backed up you years.

 

[Grytpype]

Below is a picture of what should be below the speed setting ring. There are a series of holes in the underside of the ring that should engage with the screw-in pin I've arrowed in green when you lift the ring and turn it. If this was missing or broken off it could account for your problem.

​

You would not have to take the top-cover off to get at it; just the wind-knob and the speed ring.

 

[shawn]

Thanks to all for the information. I opened up the shutter speed selector and it turns out this was an easy fix. The shutter selector dial has holes in the bottom that a pin engages in to have the hard shutter positions.

You can see the holes in the dial at:

https://youtu.be/NjJ-1DT-r6c?t=3m55s

And the pin on the body is at about at the 1 oclock position.

This wasn't happening on my IIa.The top cover was loose on that side as the two screws to hold the cover down were missing and that prevented the pin from engaging in the holes on the shutter dial. I borrowed one screw from the other side to hold down the cover and now the shutter dial locks into place. When locked at 1/250 the shutter is firing properly as it is at all other settings.

Anyone happen to know the size of the screws that hold down the cover? I want to replace the two missing screws.

Here is the camera (functioning properly now) with the f2 lens it came with.

And this is it with the post war Carl Zeiss f1.5 I will shoot it with.

Rangefinder is clean and clear with great contrast, focus is smooth. Should be ready for a film test.

Thanks again,

Shawn

 

[shawn]

Below is a picture of what should be below the speed setting ring. There are a series of holes in the underside of the ring that should engage with the screw-in pin I've arrowed in green when you lift the ring and turn it. If this was missing or broken off it could account for your problem.

​

You would not have to take the top-cover off to get at it; just the wind-knob and the speed ring.

Thanks, great information. In my case the top cover was loose (missing screws) so that pin wasn't engaging. Now I just need to find two screws for the cover.

Shawn

 

[Steve Bellayr]

Congratulations!

 

[Highway 61]

Anyone happen to know the size of the screws that hold down the cover? I want to replace the two missing screws.

IIRC they're screws with 1.2mm metric threads and flat heads, about 2.5mm long.

 

[shawn]

Thanks, I will see if I can find some locally.

In other news I put a short test roll through the camera today. Nothing special, just shots at the park with my kids. The camera appears to be working great. I tried a pair at 1/500 f2 and the same shot at 1/1250 f1.5 and there is very little difference in exposure between the two. The faster shutter speeds are looking good.

Shawn

 

[Sarcophilus Harrisii]

Nobby sparrow sells replacements for pre-war Contax and Nikon on eBay. If the post war models take the same types (I don't know) you could acquire the required fasteners via him.
Cheers
Brett

 

[shawn]

Hi Brett,

Thanks, I tried Nobby Sparrow and he didn't have them.

EDIT: Found a cheap parts IIIa so I should be all set.

Shawn