Canon Lenses: EF 75-300mm 1:4-5.6 (dismantle and repair)

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

Irene Bujman - 12 Mar 2006 17:47 GMT

Hi Guys

I need to repair two of these.

The first is marked CANON ZOOM LENS EF 75-300mm 1:4-5.6 III

The zoom action has become stiff with use and I need to lubricate it. I'm
confident that I have the necessary tools and skill to dismantle it from the
bayonette end and rebuild it afterwards. However, I don't hace an
exploded-view diagram for this model. Can you help?

The second is marked CANON ZOOM LENS EF 75-300mm 1:4-5.6 and is the USM
model.

The inside of the lens nearest the filter end has become coated with a mould
or fungus and needs cleaning. I can remove the collar that has the screw
thread for the filters, but this reveals a further three screws that appear
to hold the lens in place. However, turning the screws (either way) has no
effect. They just stay where they are. So how do I get the lens out?

Much obliged to you for any assistance,

Sincerely
Irene Bujman

Reply to this Message

Måns Rullgård - 12 Mar 2006 18:02 GMT

> Hi Guys
>
> I need to repair two of these.
>
> The first is marked CANON ZOOM LENS EF 75-300mm 1:4-5.6 III

[...]

> The second is marked CANON ZOOM LENS EF 75-300mm 1:4-5.6 and is the USM
> model.

Just get new much better 70-300mm lenses instead.

Signature

Måns Rullgård
mru@inprovide.com

Reply to this Message

Irene Bujman - 12 Mar 2006 19:00 GMT

Nice one! I hadn't thought of that. Perhaps you'd like to pay for them?
Now, can anyone answer the questions?

Rene

> > Hi Guys
> >
[quoted text clipped - 12 lines]
> Måns Rullgård
> mru@inprovide.com

Reply to this Message

Mark Dunn - 12 Mar 2006 20:26 GMT

1) Removing the leatherette may expose some screws which retain the zoom
barrel. Removing this may give access to the mechanism. I seem to remember
doing this to a 28-70 a while back. Be careful though.
2) Pass.

> Hi Guys
>
[quoted text clipped - 20 lines]
> Sincerely
> Irene Bujman

Reply to this Message

Irene Bujman - 13 Mar 2006 01:38 GMT

Thanks. Nice to see someone gets the gist.

I'll give it a go and heed your warning about taking care. A day spent
getting it right is going to be cheaper then buying a new one.

ATB
Rene

> 1) Removing the leatherette may expose some screws which retain the zoom
> barrel. Removing this may give access to the mechanism. I seem to remember
[quoted text clipped - 27 lines]
> > Sincerely
> > Irene Bujman

Reply to this Message

Malcolm Stewart - 12 Mar 2006 21:12 GMT

> Hi Guys
>
[quoted text clipped - 10 lines]
> Sincerely
> Irene Bujman

Saw the results of an EF lens disassembly over on www.dpreview.com Canon SLR
lens forums a few days ago. I remember seeing lots of minute steel balls.
Might be worth a look.
Good luck.

Signature

M Stewart
Milton Keynes, UK
http://www.megalith.freeserve.co.uk/oddimage.htm

Reply to this Message

Irene Bujman - 13 Mar 2006 01:41 GMT

Ballbearingettes, eh? Hope they're bigger than leptons.

Thanks for the tip
Bless
Rene

> > Hi Guys
> >
[quoted text clipped - 21 lines]
> Milton Keynes, UK
> http://www.megalith.freeserve.co.uk/oddimage.htm

Reply to this Message

TommyT - 19 Mar 2006 20:41 GMT

Hi Irene,

I wonder if you have any luck dismantling the zoom lens.
My EF 75-300mm IS lens has an issue with the front barrel that I need
to disassemble
and repair it.

There is a service manual for the zoom lens available on ebay, but
it costs $35 + $5 shipment. I have been searching through internet to
see if
anyone has had any experience working on the lens so I can try it
myself first.

Tommy

> Hi Guys
>
[quoted text clipped - 20 lines]
> Sincerely
> Irene Bujman

Reply to this Message