Andreas Thaler
Subscriber
I actually didn't want this nice telephoto as a repair project, but rather as a problem-free access to my Tamron collection.
But things turned out differently and I realized once again that every lens is designed differently.
With this telephoto, which was highly praised for its imaging performance and high-quality in its time, the aperture on the camera did not work.
It was noticeable that the lens stopped down when it was removed from the camera and the aperture blades were therefore visible. With Adaptall-2 there should only be an open aperture when the lens is removed.
When the aperture lever was pressed, the aperture remained closed, and it didn't work even with Adaptall-2 adapters for different camera systems.
So I had get to the bottom of the matter.
The candidate without an Adaptall 2 adapter attached.
The cause of the problem becomes apparent even without disassembly.
The aperture lever does not contact its counterpart on the aperture register. It should connect to this where the arrow points.
Therefore, the aperture set in each case remains closed. There is no open aperture and you can therefore only take photos with the working aperture.
Dismantling the rear components.
When you press the wheel, the aperture lever should swing to the right against the spring tension and release the lever underneath. This moves the lens from open aperture to working aperture. But the lever points too far to the left and is too far back. Therefore no contact is possible.
The aperture lever removed.
And now it becomes clear that the aperture lever cannot do its job because it is severely bent horizontally and vertically.
Using the small combination pliers, I straighten the lever by eye.
Now the lever contacts its counterpart ...
… and with the spring attached, the aperture lever pushes the aperture into the open position.
And when you press the wheel, the aperture closes to the set value.
The attached adapter then makes contact here and transmits the movement of the aperture lever in the camera's mirror box, so that the aperture closes during the exposure time.
On this occasion there is the usual cleaning and lubrication service for the aperture ring, aperture catch and ball.
Putting on the aperture ring with the ball inserted doesn't work. The aperture ring refuses to take its intended position.
After a thorough search for the cause, I found the solution.
But things turned out differently and I realized once again that every lens is designed differently.
With this telephoto, which was highly praised for its imaging performance and high-quality in its time, the aperture on the camera did not work.
It was noticeable that the lens stopped down when it was removed from the camera and the aperture blades were therefore visible. With Adaptall-2 there should only be an open aperture when the lens is removed.
When the aperture lever was pressed, the aperture remained closed, and it didn't work even with Adaptall-2 adapters for different camera systems.
So I had get to the bottom of the matter.
The candidate without an Adaptall 2 adapter attached.
The cause of the problem becomes apparent even without disassembly.
The aperture lever does not contact its counterpart on the aperture register. It should connect to this where the arrow points.
Therefore, the aperture set in each case remains closed. There is no open aperture and you can therefore only take photos with the working aperture.
Dismantling the rear components.
When you press the wheel, the aperture lever should swing to the right against the spring tension and release the lever underneath. This moves the lens from open aperture to working aperture. But the lever points too far to the left and is too far back. Therefore no contact is possible.
The aperture lever removed.
And now it becomes clear that the aperture lever cannot do its job because it is severely bent horizontally and vertically.
Using the small combination pliers, I straighten the lever by eye.
Now the lever contacts its counterpart ...
… and with the spring attached, the aperture lever pushes the aperture into the open position.
And when you press the wheel, the aperture closes to the set value.
The attached adapter then makes contact here and transmits the movement of the aperture lever in the camera's mirror box, so that the aperture closes during the exposure time.
On this occasion there is the usual cleaning and lubrication service for the aperture ring, aperture catch and ball.
Putting on the aperture ring with the ball inserted doesn't work. The aperture ring refuses to take its intended position.
After a thorough search for the cause, I found the solution.