Taking my lens apart... - DPChallenge Forums

Canon EF 24-105mm f/4.0L IS

08/27/2007 04:41:00 AM · #1

So I bought a Canon 80-200 f3.5-5.6 II off of Craigslist for $40 about 5 months ago.
It's done its job while i've had it, but recently it stopped working.
It gave the camera an ERR99, and I soon discovered that one of the aperture blades came loose.

Rather than get it repaired(which would likely cost more than the lens), I tried to see what i could do.

So tonight I started unscrewing, after carefully removing a few hunks of glass, and realizing i couldn't save the aperture mechanism, things got a little violent, and I ended up snapping off plastic pieces and glass.

After trying different combinations of optical pieces removed, I now have just the front lens element. It actually works like a magnifying glass.

After hooking it up to the 20D body, it won't take a short and gives Err01.(dirty lens contacts).

Now the contacts aren't dirty, they're just not controlling anything.

Is there any way I can stop the lens from trying to converse with the body (or vis versa). I've heard there's a switch that EF lenses trip on the body telling it to communicate.

I'd like to be able to use this much like a manual aperture lens, or just something fun to use.

Should I just try to remove the contacts? Any other ideas?

Thanks for the help.

PaulE

Canon EOS-50D

08/27/2007 05:26:36 AM · #2

Hi,
I can't help you, but I'm watchign with interest. Please post photos - a) of the taken apart lens, and B) picture staken with the hack lens once built.
Paul

MrEd

Sony DSLR-A100

Sigma 15-30mm f/3.5-4.5 EX Aspherical DG DF for Minolta

08/27/2007 06:36:43 AM · #3

There's an option on my Minolta to turn off the 'lens checker', pretty sure your Canon has the same? I need to turn it off when I use my fisheye.

FireBird

08/27/2007 07:30:56 AM · #4

Originally posted by davidlinder:

Should I just try to remove the contacts? Any other ideas?

Thanks for the help.

Sorry, I travel a different path......

kirbic

Canon EOS R5

Canon RF 24-70mm f/2.8 L IS

08/27/2007 07:34:21 AM · #5

At this point, just remove the contacts, that's the easiest solution. As long as they are there, the body will think it needs to communicate with the lens, which of course no longer has a brain and thus is permanently incommunicado ;-)

Camabs

Canon EF 35mm f/2.0

08/27/2007 07:41:25 AM · #6

Originally posted by kirbic:

would this help for any lens that stopped communicating with the camera? I have Sigma that tells me ERR99 all the time, will it become a manual focus lens if I just remove the contacts?

(worth a try, doesn't work anyway)

MelonMusketeer

Nikon D7000

Nikon MF 50mm f/1.4

08/27/2007 07:56:34 AM · #7

There may be some way you can coat the contacts to insulate them from the body, like a tiny touch of nail polish on each one, applied with a tooth pick. It would be bad if the chips of polish came off inside the camera though.

Camabs

Canon EF 35mm f/2.0

08/28/2007 04:21:47 AM · #8

Originally posted by MelonMusketeer:

Great tip. It made me think of something even simpler: covering the contacts with Scotch tape. It works. I can not set the aperture and I have to focus manually, but the lens works fine now. :)

Samsung Galaxy S24, S24+, S24 Ultra

09/18/2007 09:27:57 PM · #9

so here's a late update:
I finished taking everything apart and put back together.

In the end, I took/broke everything out, except for the front element and effective turned it into a macro lens. Oh yeah, and it has a fixed aperture(probably bigger than 1, since there isn't even any aperture blades, just the diameter of the inside of the lens), fixed zoom(had to tape/glue it together), and fixed focus(took that glass out). So you basically just set it on AV mode, and walk back and forth until you get something you like. It's pretty fun.

I ended up super gluing and electrical taping over the contacts so the camera wouldn't freak out.

Flickr Gallery of the Build, and test shots

ETA: all of the test shots are straight from the camera, no processing.
also, i smudged the front element before i put it back in, and don't have the tool to get it out(just moved up to school) so i can clean it.
so for now, everything is a little soft/smudged.

Message edited by author 2007-09-18 21:29:22.

Bear_Music

Sony 24-70mm f/4 Vario-Tessar T* FE OSS

09/18/2007 09:51:26 PM · #10

I nominate this for the funniest post/thread of the week... I am giggling like a maniac and karma is looking at me like I am out of my freaking mind, which of course is what OP really is, not me... I admire the enterprise, the devil-may-care approach to life's ills, displayed herein.

R.

09/18/2007 11:05:14 PM · #11

call me funny, crazy, or whatever.

but i now have a psuedo- macro lens...

:)

And it was a fun little project too.

Message edited by author 2007-09-18 23:05:25.