Help mounting Canon FD 300f4

[Skinny Dennis]

Picked up a used Canon FD 300f4 (not an f4L) and having a heck of a time. I can't seem to set the aperture. Right now it's stuck wide open. I'm using a Fotodiox FD-NEX apapter for my a6000.

 

Turning the aperture ring on the lens has no effect. Seems there should be a manual mode where that would work, there's a green "A" next to a tiny button on the aperture select ring, but it doesn't seem to do anything. Any ideas? Couple of photos of the lens attached.

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[hansh]

Hi Skinny,

 

depends on your FD adapter. If you have an adapter with an “Open” and “Lock” mark, select “Open” and mount the lens. Now turn the ring to “Lock”. You should now be able to change the aperture.

If you have a Novoflex adapter:

• align the red dot with the white dot on the Novoflex adpter
• turn the lens to the left (align the red dot on the lens with the red dot on the adapter)
• turn the lens to the right

 

Hope it help’s.

 

Hans

[Skinny Dennis]

Hans, thanks for answering.

 

I have the 1st scenario, the Open and Lock adapter.

 

Still no manual aperture operation. The selector ring turns, but the diaphragm doesn't operate.

 

I'm still wondering what that "A" button is for.

[Bounet]

Hi Skinny, the A button is for the auto aperture function.

It's a little lock that allows you to put the aperture ring in the A position.

When mounted to a Canon SLR like a AE1 program the aperture will be fully automatic.

For you problem, when the lens is not mounted on anything, is the aperture Halfway closed like it's supposed to be?

When you put the adapter on the lens should go wide open.

If it's not doing any of that your lens have a problem.

I hope this help.

[hansh]

Hi Skinny,

 

please check if you have the adapter mounted as on the attached picture. On the adpater I have selected the "Lock" position.

 

 

 

If the adapter is mounted as shown above, the apertue can (hopefully) be closed an opend.

 

Hans

 

Sorry failed to upload the picture.

Edited September 10, 2015 by hansh

[JColeman]

Hi Skinny,

Canon FD lenses are a little different than other legacy lenses. As has been described above you have to do it in a sequence.

First with you adaptor off the lens turn the lock ring to open. Line up the dots from adaptor to lens. twist on, when fully on turn lock ring to open.

If you look into the rear of the lens you will see a pin move the lever on the lens. At this point you should be able to move the aperture ring on the lens.

Hold the lens where you can see through it. Rotating the aperture ring you should see the aperture blades open and shut.

If these do not move they are stuck. This happens if the lens has not been in a dry storage or has been left in a hot car of exposed to high heat.

These old lenses have a type of grease on the barrel screw that if left in a hot car will run onto the aperture blades. I hope this is not the case because you have gotten ahold of nice lens.

 

The A button is for the old film camera, it was for locking the aperture and allowing the camera to control.

[Skinny Dennis]

JC

 

Yeah, I'm afraid the blades are stuck. That's a shame. I suppose there's no cure?

[Skinny Dennis]

Thank you Hans and Bounet, looks like I have a problem.

[JColeman]

Skinny,

One thing you might try is heating up the lens. Keep the temp. as low as you can. I would not go over 150°F. Let it soak in for about an hour and pull out and try turning the aperture ring when it is warm. Leave the adaptor on the lens.

There is a very small spring that pull the blades. It is not strong enough to over come what is sticking the blades.

Understand too I have not tried the above and not read it anywhere. But I have taken apart the FD lenses.

If the lens is clean and optics clear most likely it is grease on the blades.

The other options is taking out the elements. Just whatever you do don't start taking apart the back of the lens.

[Skinny Dennis]

JC

 

OK I'll give that a shot, I was wondering about leaving it in the car on a hot day for awhile, and monitoring temp. Also found a forum where some success has been had giving the lens a few raps by hand and working the ring over a period of days. Overall the lens is pretty clean and doesn't look like it's had much use. Hence the stuck blades.

 

Disassembly is not in the cards. I think it's stuck a stop or 2 from fully open, so I have been able to use it, as it is it's not a total loss.

[wildlightphoto]

I had trouble with my Fotodiox adapter and the 500mm f/4.5 L.  The adapter's pin to stop the lens down was not long enough and did not engage the lens' aperture lever properly.  The same adapter works fine with my other FD lens, so check the adapter to be sure it's working properly.

[Skinny Dennis]

That pin seems long enough, moves the lever full sweep.

 

Should I be able, without the adapter mounted, to move the lens' aperture lever by hand and work the aperture selection? This I can do, but the diaphragm does not move.

[1800daniel]

You are probably just using the adapter incorrectly, as others have suggested. 
1. Unmount everything
2. Set adapter to "Open" position
3. Attach adapter to lens
4. Set adapter to "lock" position - if you look inside the back of the lens to see what is going on while you go from "open" to "lock," you should see the pin moving; the aperture should now be functional when ring is set to "lock"
5. Attach lens and adapter to camera 

If the lock ring on the adapter is not set to "open" when attaching a lens, the aperture will not operate.
I have many FD lenses and the Fotodiox adapter for my a6000 as well.
Let us know how the lens performs. I was looking at getting the L version sometime.

[wildlightphoto]

Should I be able, without the adapter mounted, to move the lens' aperture lever by hand and work the aperture selection? 

 

No.

[wildlightphoto]

Let us know how the lens performs. I was looking at getting the L version sometime.

 

I've had the L version for a week.  My initial testing suggests it's  'keeper'

 

There's some lateral chromatic aberration which can be corrected in Photoshop.  Once corrected the images are quite sharp as long as you don't pixel-peep in the corners.

 

full image:

 

 

 

crop (click on image to enlarge):

 

[Skinny Dennis]

You are probably just using the adapter incorrectly, as others have suggested. 

1. Unmount everything

2. Set adapter to "Open" position

3. Attach adapter to lens

4. Set adapter to "lock" position - if you look inside the back of the lens to see what is going on while you go from "open" to "lock," you should see the pin moving; the aperture should now be functional when ring is set to "lock"

5. Attach lens and adapter to camera 

 

If the lock ring on the adapter is not set to "open" when attaching a lens, the aperture will not operate.

I have many FD lenses and the Fotodiox adapter for my a6000 as well.

Let us know how the lens performs. I was looking at getting the L version sometime.

I've used this method previous to your post many times, and I gave it another shot today, per your steps.

 

I can see the pin moving. The diaphragm doesn't operate. I think I have a dead horse here.