Trying to repair a Vivitar 24-48mm lens

[Kozhe]

Hi guys,

I got an old Vivitar 24-48 lens from my dad which aperture control didn´t work. Since a repair may cost a lot more than a new one, I decided to give it a try and see wheter I can fix it by myself.

I open it yesterday an found that everything seems to be perfect, but there´s a small spring (about 1 inch long, 1mm wide, the only spring I have found so far) which is attached to the aperture ring and seems to be really soft.

Do you think this is the fault and changing this spring would solve the problem, or there must be something else I should check? Also, where can I get a spring like this?

 

[ClaremontPhoto]

What exactly isn't working?

On many lenses changing the aperture ring does not change the actual aperture at that time.

Pressing the shutter, or using the 'stop down' button, will change the aperture when needed.

 

[zuikologist]

It might be oil on the blades which is stopping them moving at all. I have not seen the 24-48mm. If it was made by Kiron or Cosina, lenses from these makers are known to have gummy blades from time to time. Exercise the stop down pin and see if the blades move. You might then see the oil.

 

[Kozhe]

The aperture ring does nothing, neither the "dof preview" button. When I open it, I saw that both controls where completely free, with no effect at all, like that spring didn´t push the aperture blades against the angle set by the control ring. I also have a Vivitar 70-210 and works perfectly.

My initial idea is that either the spring is too soft after 30 years or the ap. blades are not lubricated enough, although they look pretty nice so far. I can see some nice looking oil on the blades when I push and pull their actuator.

 

[ClaremontPhoto]

Just to get this right: have you set the aperture to f22 and then pressed the stop down button (after making certain you're not pressing the bayonet release button)?

 

[Kozhe]

Yep, but nothing happens

 

[Peter_Jones]

Get rid of the oil on the blades - lighter fuel should do that very well. The oil makes them stick together, they should run dry.

Hope this helps sort the lens out.