How I fixed a dropped AFS ED 28-70 F2.8


Wow, as a 28-70mm f2.8 owner myself, I was fascinated to see what was inside 'The Beast'.. Nice work fatigue! :thumbsup:
 

Very off topic, but does this 28-70 f2.8 lens have any mechanism to prevent water leakage? I would rather hear from a person who actually take these things apart rather than go by publicity material of the manufacturers.

Just like majority of DSLR lenses, none
 

Impressive work David! I should have documented my work like this when I dismantled a Calibre 16 movement last time ;)
 

thanks for sharing. You make it look so simple. I always wondered about yr back ground... hahaha...

btw, when i was younger, i bought a second hand lens. In a few weeks after i bought it, fungus consumed the lens. How true it is that only the original manufacturers have special equipments that keep the fungus at bay when they carry out the repairs?
 

thanks for sharing. You make it look so simple. I always wondered about yr back ground... hahaha...

btw, when i was younger, i bought a second hand lens. In a few weeks after i bought it, fungus consumed the lens. How true it is that only the original manufacturers have special equipments that keep the fungus at bay when they carry out the repairs?

I signed an NDA....hahaha
 

NDA on your background or disclosing whether there were special techniques to prevent fungus if it were repaired by a non-manufacturer repair man? haha...
 

Just want to say a word of thanks for taking the effort to show us the intricacies of an AFS lens. An eye-opener for many of us for sure. Really doubt I will try this myself -- but I'll be a lot more careful the next time I use the 28-70/2.8...
 

Coming up next...17-55mm F2.8 AF-S
 

Do a series on youtube :)
 

Coming up next...17-55mm F2.8 AF-S

.....wow u have a habit of dropping your lenses?....just joking.....great job there.....I took apart an old canon manual lens....all the little balls just drop out....never got around putting the whole thing back...hahahaa.
 

Amazing handiwork! :thumbsup::thumbsup:
 

wow that's amazing man.
I wish i can do that to my beloved afs 28-70 lens. But once i noted the lens did not response to my F5 autofocus, i had sold it. I dont know what & why. The same thing happen to AFS300mm f/4. A bit off topic, but i love what you've shared here!
Cheers,
 

Hi Fatigue,
Thank you very much for posting this.
At least I am not the only one that dare to dismantle such a lens!
I have the same lens and the zoom ring became very hard around 50-55 mm and also the focus was giving some issues. So I decided to open it... very carefully!
I did not open the lens completely so far. I only checked inside. As the ring was now turning freely, I decided to re-assemble. I am stuck at the aperture ring.
I have open another lens 17-35/2.8 to check and there I find the trick. The pin attached to the aperture ring needs to slide in between 2 tiny pieces of metal inside which are both attached to a string in opposite direction. I re-assembled that lens 17-35/2.8 with no major problem.
However with the 28-70/2.8, when I do the same - sliding the aperture guide inside the 2 pieces of metal commanding the aperture inside the lens, the aperture ring does not move enough to the left. The top piece on the right is touching a little triangle on the bottom piece on the left and so stop the aperture to open fully. It seems that the way I slide the aperture is the only possible way. For that, I introduce a tiny screwdriver on its left side to move the bottom piece of the mechanism inside the lens to the max to the right, which aperture fully closed at 22. Then I introduce the aperture ring but not completely so that the aperture guide is only touching the top piece of the mechanism inside the lens. When I slighly move the aperture top guide (the one going into the camera body) to the left, the bottom aperture guide then only moves the top piece inside and as soon as that piece is far enough to the left, I only have to push the aperture ring inside... et voila! Quite easy but something is wrong.
I hope my explanation are clear enough for you to understand... I am doing something wrong? Can you help?
Paul
 

Hi Fatigue,
Thank you very much for posting this.
At least I am not the only one that dare to dismantle such a lens!
I have the same lens and the zoom ring became very hard around 50-55 mm and also the focus was giving some issues. So I decided to open it... very carefully!
I did not open the lens completely so far. I only checked inside. As the ring was now turning freely, I decided to re-assemble. I am stuck at the aperture ring.
I have open another lens 17-35/2.8 to check and there I find the trick. The pin attached to the aperture ring needs to slide in between 2 tiny pieces of metal inside which are both attached to a string in opposite direction. I re-assembled that lens 17-35/2.8 with no major problem.
However with the 28-70/2.8, when I do the same - sliding the aperture guide inside the 2 pieces of metal commanding the aperture inside the lens, the aperture ring does not move enough to the left. The top piece on the right is touching a little triangle on the bottom piece on the left and so stop the aperture to open fully. It seems that the way I slide the aperture is the only possible way. For that, I introduce a tiny screwdriver on its left side to move the bottom piece of the mechanism inside the lens to the max to the right, which aperture fully closed at 22. Then I introduce the aperture ring but not completely so that the aperture guide is only touching the top piece of the mechanism inside the lens. When I slighly move the aperture top guide (the one going into the camera body) to the left, the bottom aperture guide then only moves the top piece inside and as soon as that piece is far enough to the left, I only have to push the aperture ring inside... et voila! Quite easy but something is wrong.
I hope my explanation are clear enough for you to understand... I am doing something wrong? Can you help?
Paul
 

nice share!
now no one can complain why it's so costly to repair their lenses :bsmilie:

hope i wont have a chance to patronize you to do the above that u shared ;p
 

Thanks for sharing.
 

nice sharing..................:)
 

You looked like you've just diffused a plutonium bomb! :thumbsup: Impressive!
 

Hi Fatigue,
Thank you very much for posting this.
At least I am not the only one that dare to dismantle such a lens!
I have the same lens and the zoom ring became very hard around 50-55 mm and also the focus was giving some issues. So I decided to open it... very carefully!
I did not open the lens completely so far. I only checked inside. As the ring was now turning freely, I decided to re-assemble. I am stuck at the aperture ring.
I have open another lens 17-35/2.8 to check and there I find the trick. The pin attached to the aperture ring needs to slide in between 2 tiny pieces of metal inside which are both attached to a string in opposite direction. I re-assembled that lens 17-35/2.8 with no major problem.
However with the 28-70/2.8, when I do the same - sliding the aperture guide inside the 2 pieces of metal commanding the aperture inside the lens, the aperture ring does not move enough to the left. The top piece on the right is touching a little triangle on the bottom piece on the left and so stop the aperture to open fully. It seems that the way I slide the aperture is the only possible way. For that, I introduce a tiny screwdriver on its left side to move the bottom piece of the mechanism inside the lens to the max to the right, which aperture fully closed at 22. Then I introduce the aperture ring but not completely so that the aperture guide is only touching the top piece of the mechanism inside the lens. When I slighly move the aperture top guide (the one going into the camera body) to the left, the bottom aperture guide then only moves the top piece inside and as soon as that piece is far enough to the left, I only have to push the aperture ring inside... et voila! Quite easy but something is wrong.
I hope my explanation are clear enough for you to understand... I am doing something wrong? Can you help?
Paul

Hi Paul, first of all, welcome to Clubsnap. I’m glad your 1st and 2nd posts are on the thread I started. ;)

Your procedure is great!
Sometimes, you can take advantage of the difference in height of the 2 small metal pieces to slide-in the aperture control. If the 2 small pieces doesn’t want to cooperate, then I use my sharpened chopstick.

Thank for helping me out! I find it really hard to describe the procedure of sliding the aperture control, a procedure that usually takes a few seconds to perform.
 

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