Saturday, 11 April 2009

Repair Canon 18-55mm Zoom Lens

Welcome to Macro Photography for Beginners. I recently used precision tools to take apart my canon kit lens.

The Canon 18-55mm EF-S 1:3.5-5.6 zoom lens has become known as the standard kit lens sold with most new Canon Digital SLR cameras (with a APS-C sized sensor). The lens was originally designed specifically for the Canon 300D but has since become available as a stand alone lens. It has been equally criticized and praised by photographers during its short and illustrious lifetime. In my opinion it is an almost adequate lens with a fairly average/variable performance.

There are three reasons why I decided to dissect my Canon 18-55mm EF-S 1:3.5-5.6 zoom lens. The first reason is that the auto-focusing was "hunting" or to put it another way going backwards and forwards continuously. The second reason was to resolve a common problem with the Canon 18-55mm EF-S 1:3.5-5.6 zoom lens. I have read several accounts that suggest that this lens allows moisture to accumulate inside the casing. The moisture condenses on the inside of the glass resulting in a water mark on the glass. Images from my lens became cloudy for a large proportion of the frame. When inspecting the lens for damage it was evident that my lens had succumbed to the problem mentioned above. When looking through the lens with the naked eye it was possible to see a large water mark on the inside of the glass. The lens in all honesty was rarely used and would not be sadly missed if my attempted repair went wrong. I decided to operate on the lens and find out exactly what goes on inside a Canon 18-55mm EF-S 1:3.5-5.6 zoom lens. This post is a supplementary addition to back-up recent reports that I am probably crazier than a soup sandwich (the third reason = my own curiosity).

The first point to make about this operation is that I am fairly competent person with a good knowledge of electronics. The second point to make is that the lens was useless in its present state. I would not recommend that you dismantle a Canon 18-55mm EF-S 1:3.5-5.6 zoom lens or any other piece of electrical or photographic equipment, unless you know what you are doing or are fully prepared to lose the lens/equipment as part of the learning experience. So what is inside a standard Canon 18-55mm EF-S 1:3.5-5.6 zoom lens?

How to get Inside the Lens
First of all I wanted to investigate the problems with the auto-focus on this lens. This means delving into the electronics and most importantly find the motor inside. I’ve read a few photography forum threads about how difficult it is to get inside the lens. Let me assure you that it is not actually very difficult to get inside but once inside it is rather complex and delicate. I recommend placing the lens cap onto the lens for added protection. Then turn the lens upside down on a suitable work surface. Take off the rubber seal which is present around the centre of the reverse part of the lens. To gain entry into the lens (using precision tools) remove the two screws holding the contacts in place. It will not come apart fully with these screws in place and the soldering could be damaged if the lens casing is forced open. Then remove the four holding screws that are clearly visible around the edge of the lens casing. Carefully lift the casing away from the lens to reveal the circular circuit board underneath.

Canon 18-55mm EF-S 1:3.5-5.6 zoom lensImage 1: The circular circuit board inside the Canon 18-55mm EF-S 1:3.5-5.6 zoom lens

To get further into the lens requires disconnecting the flat cables from their interfaces. These can be pulled out quit easily using the correct precision tools. They are however, not as easy to re-connect and also very delicate. If these cables are not correctly assembled (or damaged) the camera will not detect the lens and an error message will be displayed on the camera. If at this point you are still determined to go further into the lens remove the two silver-coloured holding screws.

Canon Kit LesImage 2: This is the view below the circuit board. The electronic motor can be found below the metal housing in this image.

The motor housing can also be removed and the motor examined. This requires the removal of several components that are very difficult to put back into their exact positions. In the overall image shown the electronic motor that operates the auto-focus is housed below the metal plate.

How to Remove the Water Mark
When I did manage to rebuild the lens the auto-focus was still not working. I think that there is a moral in this story somewhere. I made a tool to remove the front glass from the lens. The tool was basically a length of wood with two modified panel pins fixed through it. The pins where aligned with the two small holes on the front of the lens where it says 58mm Canon Zoom Lens EF-S 18-55mm 1:3.5-5.6 Canon Inc. The tool that I made fitted perfectly and also was designed in a way that kept it away from the glass even if it slipped (which it did several times). To remove the outer glass from the Canon 18-55mm EF-S 1:3.5-5.6 zoom lens it has to be turned anti-clockwise and it is initially very tight. It takes a lot of force to unlock the glass which gives a satisfying “crack” when it does eventually turn. When the tool I was using did slip out of position it etched unsightly marks into the plastic casing. The front glass has to be unscrewed completely from the lens casing which takes many turns. Once removed it can be easily cleaned and returned to the lens casing. I used Eclipse cleaning fluid which is designed specifically for cleaning camera equipment and dries without leaving any residue. I also used what is known to as a “magic cloth”. This is also specifically designed for cleaning camera/optical equipment and leaves no marks or dust particles on the glass surface. I used a rocket blower to ensure that no dust was left in the chamber of the lens before screwing the front glass back into the lens. This was really a very simple task.

Lens Glass Removal ToolImage 3: This is the home made tool that I used to remove the outer glass from the lens. It is crude, simple and effective (very much like myself).

In conclusion there was no real reason to take the electronic parts of the lens apart other than my own curiosity. I could not get the auto-focus to work but it was already not working properly when I started. I might re-investigate the auto-focussing problem and test the motor. In the meantime the lens can still be manually focused and after being cleaned the fog from the water mark on the glass is gone.

Macro Photography Hot DrinkImage 4: The lens is now safely reassembled and it was time for one of these! No, not a hot drink (although I did obviously drink that afterwards) but a test shot to show that the lens is still in working order (minus the auto-focus). Incidentally I used my ring-flash to take this image as well! Just a quick note: The ring-flash does not fit on this lens but it can be held in place manually.

It is a very rare occasion indeed when I remove my macro lens. It is even rarer when I replace it with the Canon 18-55mm EF-S 1:3.5-5.6 zoom lens . I can still use my lens (manually) until I get around to replacing it. Well, that concludes this post which is not strictly about macro photography but more the curious nature of the macro photographer.

Marvin Africa


urmiraj14 said...

haha so you went ahead and wrote out a post on taking apart the lens :)) I have bookmarked it for future reference (and for a chuckle :P)

"When I did manage to rebuild the lens the auto-focus was still not working. I think that there is a moral in this story somewhere." <- hilarious :D

Marvin Africa said...

Hello Urmi,
Yes, I managed to string a couple of sentences together on the subject :-)

I've also made the first prototype of my bracket to hold my Sigma EM-140DG away from the camera & lens.

Sometimes when you buy electronic goods their is a small sachet of silica gel in the box. It always says do not eat on it, which make me wonder what one would taste like. Anyway, I suggest collecting these sachets & keep them with your camera equipment to absorb any moisture. Then if you are lucky you will not be taking your kit lens apart in a couple of years time to repair it:-P

KansasA said...

Oooo I have been where you have been :) Not specifically taking apart a Canon lens, but many electronic pieces where I sort of hold my breath throughout the procedure praying that when I get it back together it won't be worse than when I started ;) Great post! lol

Marvin Africa said...

Hello Kansas A,
Sorry for the delay...I've been very busy. I've always enjoyed taking machines and devices apart to find out how they work. My fist tip would be to always use the correct tool for the job. This applies to all aspects of life not just for electronics or photography.

The problem of course is putting them back together. My top tip is simple: take photographs at each stage in case it gets too complicated. This can help with complex configurations and wiring when reassembling the gizmo. A camera can be a really useful device!

Another less helpful tip: don't hold your breath for too long, you might turn blue.

Anonymous said...

I stumbled across your blog while looking for info on repairing this same lens. In my case my toddler had dropped my 350D a couple of feet to a hard floor and the focusing tube had been knocked off of it's rail. After reading your article I decided to just open it up and have a look, as like you I had little to lose by trying.

I had to go a lot further than you however and virtually stripped the lens right down (although it turns out I didn't need to). I got the lens straightened out, but unfortunately it now doesn't auto focus.

About half way down the lens is a metal contact with 5 'finger' contacts the run across some rails. In mine they are all bent up and beyond repair when they have been forced in a position they shouldn't be in.

I'm pretty sure that this is part of the auto focus, so it might be worth you having another look there however to see if there is some minor damage to the contacts in your lens. Just one screw keeps them in place but be careful as it's pretty delicate.

Anyway, nice blog you have here. I'm just getting started with macro photography, so I'll be back to read some of your other articles soon.

Roops said...

I got this lens from someone who it fell in the ocean from. The lens had 2 water spots inside it, and the auto focus was not working. I soaked it in distilled water first for 2 days to try and get the salt water off. Water ended up getting inside the lens element. I am still hoping that it will dry out.

I searched on google for repairing this lens, and I was happy to find your tread and took the electronics apart. I cleaned everything with rubbing alcohol and put it back together. The good news is that my auto focus is working again!

I still have water spots inside my lens element though, and the camera can not "see" anything through the lens. I need to make a tool to remove the front element and clean the optics manually. I will update you on the repair in progress.

Marvin Africa said...

Hello Piratekaya,
I think we went the same distance, much further than my post suggests, but I never took a picture of the empty lens barrel!

There is a six finger connection (visible in image 2). It is obviously an important connection between the auto focus motor and circuit board.

...maybe worth heading to Ebay (or other auction sites) for a cheap replacement!

These lenses are slightly tricky, but not impossible to focus manually.


Marvin Africa said...

Hello Roops,
I wrote this post to prevent this situation happening to other people!

You can make a tool like mine but take care not to scratch the glass if it slips out of place. It takes a lot of force to unlock it (and you will grow a beard whilst unthreading it - even if you are a lady).

Use a high quality product to clean the glass (like eclipse fluid) and a magic cloth as this combo will leave no residue or ugly streaks on the glass.

Good luck with it...


TaigaAK said...
This comment has been removed by the author.
delion619 said...

Can anyone help me with my Canon EFS-18-55mm US broken lens. The outer end of the sleeve barrel where you attach the UV filter is cracked. I plan to buy the sleeve barrel from canon to replace it myself. Does anyone know whether i should start to disassemble from the back end of the lens or the front of the lens. Thanks

KB04090 said...

Thank you for your post. My problem was with zoom, so I kept searching for a solution. Found this page ( which offers detailed re-assembly of the focus mechanism to ensure that manual and auto focus work:

1. Do as the guide tells you and strip everything down to where the loose screws are accessible. [The zoom problem is caused by a loose screw on the side of the "guts" of the lens (photo provided on above page.]

2. As thydzik wrote in the comments and posted a picture about:
A 1 cm black plastic pin is marked with a green circle. Move this pin to the outermost position.

4. Position the two silver prongs, coming from the autofocus unit (the unit in the left side of this picture so they straddle the black plastic pin.
If these parts aren’t put together correctly, no focussing will take place since the focus engine/manual focus grip isn’t moving anything around.

3. Set the focus on macro and the zoom to 17 and put everything together again.

4. Voila the world isn’t blurry anymore!

//end quoted

Hope this helps you! Kris

Marvin Africa said...

Hey Kris, thanks for this comment. I've not checked all the links so I'm trusting that you've not posted a right load of old horse poo!

Retrieved from the grasping arms of the spam filter! It hates links of any kind [active or not]