Soligor 28mm FD mount aperture not closing

EdH · Joined: 24 Nov 2014 Posts: 47 Location: Devon, UK

I recently bought this lens in seemingly excellent condition. It's my first FD mount lens and it took a bit of googling and fiddling before I could mount the FD-Micro 4/3 adapter. However, the aperture seems to be stuck wide open.

I'm hoping it's something to do with the way I've fitted the adapter (although it seems I've tried every way of doing it) rather than the lens actually having stuck aperture blades, although I'm starting think this might be the case.

I think it's the breechlock mount.

SoligorCD28mmf2.8_1 by Ed Herridge, on Flickr

I've made sure the Lock/unlock pin in the adapter is the correct side of its lever. With the adapter mounted, the aperture lever on the back of the lens is moving when I turn the aperture ring but to no effect.

I'd be grateful for any hints or ideas.

luisalegria · Expire: 2018-01-18

Does the aperture close with the adapter off ?
On Canon FD like this IIRC you need to press one of the fat round pins then move the big lever to close down.
Set aperture to F/16 or 22 and fiddle with the pins and levers on the FD mount.
If the aperture is working at all you should be able to do this.
If you can't close the aperture at all, its probably stuck.
Very common problem. Usually due to sticky lubricant on the blades and blade mechanism.
Usually not a hard fix.
Disassembly is usually easy on these.
Get down to where you have access to the blades and some patient work with naptha/lighter fluid and q-tips will get enough old grease off to make it work again.

Lloydy · Expire: 2022-01-01

The adapters I have for Canon FD to Sony E mount have a twist ring to move the actuating lever on the back of the lens that allows the aperture to open and close as the aperture ring on the lens is turned.
As Luis says, there can be a pin that has to be pressed as well, Canon mounts can be a mystery. Especially the breechlock Rolling Eyes

Inside your adapter there should be a lever / pin that rotates a few degrees as the ring on the adapter is moved from open to close. That pin should contact the lever on the Canon lens - 11 o clock in your picture - on the straight side, which is 'open' on my adapter. Then, when the adapter ring is turned to 'close' the lens lever is moved slightly and allows the lens aperture ring to move the aperture blades. This can all be dependent on the pin in the lens mount being pressed - but not all Canon or Canon fit lenses have that pin - I have a Soligor with breechlock in front of me that has no pin, so I can move the lens lever with my finger, move the aperture rind and the blades open or close. But a Canon non breechlock has the slightly hidden pin in the mount and has to be mounted on a camera, adapter or have the correct lens rear cap on it to enable the same operation.

The thing to remember is that the lever at 11 o clock in your picture has to be moved a few degrees anti clockwise to enable the aperture to be worked from the lens ring. Try it with the adapter off the camera so you can see through it to the back of the lens.

cooltouch · Joined: 15 Jan 2009 Posts: 9109 Location: Houston, Texas

I need to edit what I just wrote because I had some things backward:

Just to add to the above, the larger lever in your picture in many/most/all? FD breechlock lenses can be locked all the way in one position and when it is, the aperture works. You can just push on it to lock it and unlock it. It clicks in place and clicks out of place. Just looking at the pic, it looks like it's in its unlocked position. But to do this, you have to rotate the breechlock ring.

If the breechlock ring will not turn when the lens is dismounted, which is typical with Canon FD and most aftermarket FD mount lenses, you can get it to turn by depressing a small button or tab that is usually at least partially obscured by the ring itself. I can usually reach it with a fingernail, but failing that, anything narrow and thin can be maneuvered under the breechlock ring to depress the tab or button. So after you do this, you can rotate the breechlock ring, and when it's in this position, you should be able to get the aperture to work. Again, try pushing on the tall lever in the other direction from what's pictured to see if it locks in place and to see if your aperture iris works.

If it doesn't, the blades are stuck and will need to be degreased.

EdH · Joined: 24 Nov 2014 Posts: 47 Location: Devon, UK

Thanks for the advice.

The larger lever does move and is actuated by the lock/unlock ring on the adapter. It does not lock into place by itself and will spring back if released. The aperture lever also moves with aperture ring, but the silver metal you can see in its slot does not move or follow the lever as you move the aperture ring toward wide open.

None of the three pins on the top of the mount (the two narrow ones or one fat one) don't move at all. They're solid, and there's nothing on the adapter with touches them. There is a pin, which can be obscured by the mount and that I hadn't found, which does push down. However, depressing this, while holding the large lever over and moving the aperture ring (I could do with an extra set of hands for this!), doesn't seem to make any difference.

Looks like I'll be opening the lens. Thankfully it wasn't very expensive, as my previous efforts at opening lens haven't been successful, but hoepfully I've learnt from my mistakes!

Lloydy · Expire: 2022-01-01

To check Canon lenses I have a genuine Canon back lens cap that I have cut the middle out of so I can see through it and see the aperture blades clearly, and reach in and move the lever. You can use a complete cap, but it's harder to see the blades without light passing through the lens, and of course you cannot move the lever on the lens.
The proper cap will push the pin partially hidden under the mount - if there is one. The 35 / 2.8 Soligor that I have on the desk right now, with Canon breechlock, does not have a pin that the camera mount / lens cap pushes down. The lens cap just falls into place and allows the breechlock ring to be rotated.

But....there must be a pin or some mechanism attached to the breechlock ring - with no cap or adapter in place and the breechlock in the position it would be when a lens is locked on to a body, I can set a small aperture - move the lever and the aperture closes.
If I rotate the breechlock to the position for removing the lens from the camera mount and do the same thing, the aperture does not move.
Looking from the back, turn the lock ring anti clockwise, set the aperture to f16 and see if the blades move as you move the lever?

EdH · Joined: 24 Nov 2014 Posts: 47 Location: Devon, UK

I don't have a rear lens cap, but the adapter should be depressing the hidden pin. I can stick my finger in and fiddle with the levers, but the blades don't move whatever I seem to do. I think the silver metal part I can see in the aperture lever slot, that the aperture lever pushes against at f16, should push back and follow the the lever as I manipulate the aperture ring towards wide open. The strange thing is that the silver metal part is stuck at the f16 position, not the f2.8 position, and yet the aperture is stuck open, not closed. The question is, is it stuck or is there a pin or lever to release it?

luisalegria · Expire: 2018-01-18

The slot/pin you point out is for signalling the set aperture to the camera metering system.
Mechanical open aperture metering systems require something like this.
The pin will move as you move the aperture ring. That's not your problem.
For testing just set the aperture ring to f/16.

The bigger pin in its slot should get hit by the shutter mechanism to stop the lens down when taking a picture.
The trouble with Canon mounts is that yet another pin/button needs to be pressed to make this functional, which is pressed when the lens is mounted on a proper FD mount. Later Pentax screw mounts, annoyingly, have something similar.
Our problem, us would-be givers of advice, is that we aren't sure which pin it is.

On the whole if you have tried setting aperture to f/16, have tried pressing all the other pins, and it still doesnt stop down, then the aperture blades are probably stuck. This is a very common problem.

Lloydy · Expire: 2022-01-01

On my Soligor, which I think is the same as yours - rotating the breechlock ring anti clockwise allows the lever identified in your last picture to move, also anti clockwise, and then the other lever can move the aperture blades. The C/FD mark should be by the large single silver button at the top of the picture, which is the lock ring in the locked position.