Canon 28-70 EF Macro

[j-dogg]

Is an incredibly easy lens to repair.

Just wanted to say that.

 

[j-dogg]

and its broken permanently......someone dropped it. The front element is loose and the part that holds it is snapped.

 

[dnjl]

Duct tape?

 

[j-dogg]

Lol

The front element only moves like 2 mm I'm thinking I might glue it in place or something and sacrifice 5 or 10mm or focal length for an awesome macro lens. I rarely shoot macro anything over 50mm anyway.

 

[Andrew K]

you've broken the front focus barrel. It's a plastic part that is held in place by 2 screws (these are zoom guides that move the front element when you zoom the lens)

It is a very common part to break. I've probably repaired a hundred or more over the years when I was a camera tech. The replacement part is basically the same as the front barrel from a EF 35-70 of the same period.

They are pretty straight forward to pull apart once you've done a few...but without a replacement part??

 

[j-dogg]

same as the ef 35-70? what about the 35-80 there's a couple cheapies in the local pawn shop.

I'll take a picture and post up what I broke exactly. I will probably need your help in getting it apart and back together lol. I know my way around tools I just did a timing belt and water pump on my Ford Probe 2.0L 4 cyl so a lens shouldn't be too bad

 

[Andrew K]

sorry the 35-80 is totally different, adn about 20 times easier to repair.....it's always the way

Not to wory - post a photo of what is broken, and I'll see if I can't help you get it fixed

Cheers

 

[j-dogg]

Okay, here is what I am working with.

This is the front element, the part next to it is what broke.

This is where it is supposed to be, as noted by the arrows.

So basically I have to find a Canon 35-70? I'm going to go check the pawnshop up the street see if they have one. Someone brought it a ton of old EF Canon stuff.

Here's a part that looks like what I need but doesn't look like the part I have in front of me. I've actually thought about disassembling the original lens and just gluing the whole thing back together and being really careful when I handle the lens lol.

The lens I have is actually an EF 28-70 Macro f3.5-4.5 II. Looks like a great piece of glass just needs fixing. I need a macro lens for my Rebel.

 

[Andrew K]

Hi

yes the part on ebay is the same part - someone has removed it from a used lens and it is a second hand part (probably). The lens unit and the front barrell were seperate parts with different part numbers...

All you need is the barrell - which you can take from either a EF28-70 or a old EF35-70 lens - they were pretty much interchangable. Your only problem is that this is also the most common part to break...

I'll have a search around and see if I can locate the part you need - I may have one in a drawer - or one of my tech friends may have one..

BTW - have you already de-soldered the back end of the lens and removed the inner barrel from the lens to ge tto the front focus barrell?

 

[j-dogg]

No, actually I put it back together except the front element and figured I'd get it apart again when the time came. How the hell do you do all that? I've got a nice iron here and I'm no stranger to soldering, just to lens disassembly.

 

[j-dogg]

This here looks like exactly what I need

It's for a 35-70, but it doesn't say if it was a macro. Are the all the same. Might pull the trigger on this one and save me some bucks, I have heard a lot of good reviews on the 28-70

 

[AgX]

I guess one of those noses is broken. In case there is space on the outside of the barrel, you could cement it with pre-heated epoxy glue and a lug on the outside.

 

[ath]

Have you tried to contact Canon for the part? The price in your last link seems pretty high.

 

[Andrew K]

it will fit. I can't recall the actual part number for the 28-70 barrel - but they were the same part as the 35-70.

If it's a bit loose then thats fine - I've used loose ones in the past without a priblem. If its a bit tight when you fit it and you zoom it then you can shave the "bumps" off the outside of the barrel with the edge of a scalpel/box cutter/razor blade...I've done this in the past when I couldn;t get the barrel I needed..

if you need any help send me a pm

 

[clarkhdl]

How do you get this lens apart, and the 35-70?

I need to dismantle one of the 28-70 lenses because the focus is stiff.

I'm practising on a 35-70. I've got the mount off, the electroncis out, the diaphragm assembly out, the front decorator ring off, but now I'm stuck.

I've now removed the rubber grip from the zoom ring, and undone on of the pins, but can't get at the one on the opposite side.

I can't get the zoom/focus assembly out of the barrel.

I can't even find a parts catalog. This thread is the only reference I can find.

Can you help please?

Thanks.

Henry