Sinar Sinaron S 180/5.6 MC Copal No. 1, very loose aperature?

[buggz]

Hello,
Newbie question.
The lens that came w/ my Sinar f2 kit purchase is a Sinar Sinaron S 180/5.6 MC Copal No. 1 shutter.
Is the aperture adjustment supposed be like really loose?
Does it tighten up when mounted on a lens board?
I hope so, as it is, it is far to easy to be changed by any slight movement.

Oh how good is this lens?
Characteristics, etc?

[cdholden]

The lens is a Sinar branded Rodenstock Sironar-N, which should be fine if you're looking for a plasmat that can offer a sharp photo if given the opportunity.
The iris should move smoothly, but I'm not sure how you define "really loose". The thing to check is that it isn't moving once it's on the camera and on the tripod. Once set to it's intended value, it should remain until changed. Mounting it to a lensboard should not be a reason for that to change.

[Frank Petronio]

No it is not supposed to be "really loose" but it is probably a simple tightening that a technician like Frank Marshman or Bob Watkins can do for not much money. You could probably still use the lens for a while if it is not "really really loose".

They are excellent, desirable lenses worth the repair. They're as good as anything out there in that focal length.

[buggz]

Many thanks for the informative replies, I will play with this for a while, and then eventually send it to someone for CLA.

[redu]

It's not the lens but the shutter where you have the problem. actually it's a very simple repair task but in case it would be costly to find the right person and to deliver the lens both ways, just get a second hand copal, compur or prontor #1 shutter (you might find for around $50-100) off of the auction site and throw the faulty one to my direction.

[SMBooth]

My Copal#0 is very loose too, I was told it normal and put some tape on the lens board under the lever area to add a bit of resistance

[Leigh]

Aperture tension on a Copal shutter is a very simple adjustment, requiring only a small flat-blade jeweler's screwdriver.

To protect the shutter, I suggest...

Remove both front and rear cells. Place them open-end down on a clean 3x5 card or similar lint-free surface.
Activate the preview lever to open the shutter blades. Open the aperture fully.
Opening both the shutter and the aperture will prevent damage to same if the screwdriver slips.

Observe a scalloped silver ring around the threaded barrel.
Look around the perimeter of that ring and you'll find a screw engaging one of the scallops.

The screw has a flat on one side of the head. The flat should point out, away from the lens axis.
Since the adjustment is loose, the screw is probably not in the correct position.

Rotate the screw counter-clockwise so the scalloped ring clears the flat (usually 1/2 turn).

Rotate the ring clockwise by one scallop distance and try the aperture control. Repeat if needed.
When properly adjusted you should be able to move the aperture lever easily with a finger nail.

When you're done, rotate the locking screw clockwise 1/2 turn (must align with a scallop).

Remount the cells.

- Leigh

[buggz]

- Leigh,
Thanks for this info, I will save this and try this someday.

[ic-racer]

Rotate the ring clockwise by one scallop distance and try the aperture control. Repeat if needed.

So now he won't be able to turn the shutter speed dial. The aperture lever should be very free moving. There is nothing wrong with the OP's shutter.

[Sal Santamaura]

...Observe a scalloped silver ring around the threaded barrel.
Look around the perimeter of that ring and you'll find a screw engaging one of the scallops.

The screw has a flat on one side of the head. The flat should point out, away from the lens axis.
Since the adjustment is loose, the screw is probably not in the correct position.

Rotate the screw counter-clockwise so the scalloped ring clears the flat (usually 1/2 turn).

Rotate the ring clockwise by one scallop distance and try the aperture control. Repeat if needed.
When properly adjusted you should be able to move the aperture lever easily with a finger nail.

When you're done, rotate the locking screw clockwise 1/2 turn (must align with a scallop)...

So now he won't be able to turn the shutter speed dial...

I have a lens that exhibits the same loose behavior. Set taking aperture and then barely look at the lever (or make a breeze near it when cocking the shutter) and it'll move off the setting. So, since adjusting the scalloped dial is a reversible process, I decided to see who's right.

It only took clockwise rotation of one scallop distance for the shutter speed dial to become immovable. Had no tightening effect on the aperture lever. I rotated things back to where they were and locked them in place.

The effective solution was to remove the entire chromed aperture-adjusting piece (it's held in place by two small Phillips-head screws), apply a small piece of tape behind the lever as a drag brake, then reassemble. Works like a charm.