HELP Need~ My 35/1.8 had its aperture blades wedged.

nahlene

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Hi guys i didn't post much in this section of the forum.... Just to say Hello first. I guess i am in a little trouble now, thanks for any helps and advices.

Tonight when i took my camera out of the coat pocket, i notice that the aperture ring become a little loose and the blades stick at a strange position without any response to my turning of the ring. It seems that something is wedged.... 🙁 This is my only 35mm lens, and i always loved it... i want to try solving the problem myself because sending it to the States for services will cost too much (i am in Canada).

Before i start doing that, i just want to get some advices about whether i should do that myself... and also, since i don't have any service manual of this lens, i am not sure how i should dissemble it. If i am only going to fix the aperture blades, should i only open the front elements and leave the rear ones alone? Is there anything particular that i should be careful with?

The aperture blades look like this now:

canon3518.jpg


Thank you for your helps. 😛

£££££
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Take one of those gripy rubber can opener helpers. Plop that on the front. Find a can or bottle ruffly the same diameter and unscrew it. That should give you direct access to the aperture blades. From there it might be pretty logical fix, but I'm not sure. I have no clue how the Canon 35/1.9 is set up inside.
 
I have experience working on that lens. I'm afraid TWoK's recommendation is less than ideal.

The first thing is to remove the outer slotted ring on the rear of the lens. That holds the optics into the focusing mount. When you pull the optics out the front, be careful not to lose the shim ring(s) used to space it for collimation.

Now, make scribe marks to show how tightly the front and rear lens cells are screwed into the center aperture ring shell. These are matched marks on both pieces of metal where they mate.

Now you can unscrew the front and rear cells from the aperture ring shell. Put them aside in tissue for safekeeping.

Take off all the hardware for the aperture ring. There's a snap ring you'll need to ease out. There's a peg screwed into the moving slotted actuator for the aperture sticking out that connect to the aperture ring -- remove that peg.

Now you should be able to lift the internal slotted actuator ring out from the front.

Remove blades. Pray that you didn't shear the operating pins off of either end of any of them. If you did you are totally screwed.

Clean them REALLY THOROUGHLY with naptha (lighter fluid). Same with everything inside the aperture shell, including the actuator ring.

Go absolutely nuts trying to put the blades back in, getting the bottom pins in the matching holes. Putting in the last one under the first one without knocking them all back out of the holes is maddening. Don't try and do this when you are tired and frustrated!

Put the slotted actuator ring back in with the hole for the peg at the correct end of the slot through the aperture barrel. Replace peg.

The rest of the reassembly is hopefully obvious. Only place for a very little grease is the where the f-stop ring slides.
 
I have experience working on that lens. I'm afraid TWoK's recommendation is less than ideal.

The first thing is to remove the outer slotted ring on the rear of the lens. That holds the optics into the focusing mount. When you pull the optics out the front, be careful not to lose the shim ring(s) used to space it for collimation.

Now, make scribe marks to show how tightly the front and rear lens cells are screwed into the center aperture ring shell. These are matched marks on both pieces of metal where they mate.

Now you can unscrew the front and rear cells from the aperture ring shell. Put them aside in tissue for safekeeping.

Take off all the hardware for the aperture ring. There's a snap ring you'll need to ease out. There's a peg screwed into the moving slotted actuator for the aperture sticking out that connect to the aperture ring -- remove that peg.

Now you should be able to lift the internal slotted actuator ring out from the front.

Remove blades. Pray that you didn't shear the operating pins off of either end of any of them. If you did you are totally screwed.

Clean them REALLY THOROUGHLY with naptha (lighter fluid). Same with everything inside the aperture shell, including the actuator ring.

Go absolutely nuts trying to put the blades back in, getting the bottom pins in the matching holes. Putting in the last one under the first one without knocking them all back out of the holes is maddening. Don't try and do this when you are tired and frustrated!

Put the slotted actuator ring back in with the hole for the peg at the correct end of the slot through the aperture barrel. Replace peg.

The rest of the reassembly is hopefully obvious. Only place for a very little grease is the where the f-stop ring slides.

Thank you so much for your help~ and Twok too, i will try doing it this weekend.
 
During the process

During the process

Hi thx for the instructions, i managed to take the lens apart to this point that every screws i could find had been taken off, the rear optic has a black slotted ring with it, i guess it should be removed too, since the inner one is removable, but it doesn't move no matter how i turn it... Is it the right one to dissemble? i tried everything but this place seems to be the only place that i left before reaching the blades. Thx.

repair.jpg
 
That ring should easily come out. I use a rubber mat, and have not resorted to using one of my three spanners. The three range from light duty to taking pipes apart. Something mught be jamming it.
 
The aperture mechanism comes out the front, so it's not necessary to remove the rear lens cell, just desirable to protect it while you work. You do have to get the front cell out. Rubber dishwashing gloves will give you a better grip.

The front cell is black anodized aluminum, where the aperture shell is clear aluminum.
 
I have a Zeiss 85/1.4 with a messed up aperture mechansim that not even DAG has spare parts for, so I use it wide open. I have a Konica III with a similar problem, but the shutter is also messed up, and the camera is a pretty paper weight.

It is not a total loss if the repair of the Canon 35/1.8 is not possible.
 
hi guys i tried to continue the work today, as John suggested i tried to open the front element, but no matter how much for i apply, and with hands or rubber mat or leather mat, it doesn't move a little bit... now my hands are very tired 🙂 just want to double check, this is the ring that i should screw off, isn't it? i believe i have unscrewed everything possible, so it is a little strange.

repair2.jpg



Thx alot for all your helps.
 
I have a Zeiss 85/1.4 with a messed up aperture mechansim that not even DAG has spare parts for, so I use it wide open. I have a Konica III with a similar problem, but the shutter is also messed up, and the camera is a pretty paper weight.

It is not a total loss if the repair of the Canon 35/1.8 is not possible.

yeah i have that in mind, even if it turnout to be messed up, at least i can keep it as it is my first ever owned RF lens and which dead in my hand... I will try my best before i bury it under my bed, as i cannot afford another fast 35mm lens at the moment. 😛
 
I was trying to clean the oily blade. I dissembled the rear elements with wrench and was able to access the rear part of the blade... I didn't know how to open it from the front.

btw. anyone has a graph to show how the six elements arranged? Thank you.
 
A (rubber) strap wrench works wonders in this situation....and pretty handy w/ new glass jars w/ metal lids too.

You can exert a lot of force w/ one w/o marring the surface. They are available at most hardware stores. Try it!
 
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