I Love my 400/4 DO lens and over the years wonderful images were captured with it, until.......
recently there was something loose inside. It was the AF distance scale which is normally visible through the clear window as the AF is rotating.
I found out that Canon USA does not support this lens any more.
Desperately, I thought to fix it by myself. I was hoping that this loose part can be pulled out through the control switches opening. The four screws were carefully removed exposing the loose scale which is a plastic part.
To my surprise this part is not secured to the AF internal real with nothing other than contact glue.
Over the years the glue was drying out causing the scale to become loose, wondering around in the internal cavity.
What a shame.
It is a bit tricky to pull the curved plastic out, but it is doable.
If anybody encounters the same problem I am willing to provide more info.
The bottom line is:
My beloved 400/4 DO is now convertible.
I am wondering if this is the practice used in "L" lenses, and I own quite few of them.
In case same thing happens to "L" lens, it shall not be as forgiving as the 400/4 especially if Canon is not willing to re-glue the AF scale.
Not an "L" lens. The post was corrected.
My opinion is that if using glue in a product which is expected to withstand shocks during field use, at least add some snap pins which can be made from nylon.
I paid 55K for brand new SUV which the engineers who designed it thought the same as you.
They attached the back doors cover panels with double sided tape. In this case they also used nylon pins. With all the above, after several car washes the panels started to separate.
It seems that certain glues are reducing the longevity of a product.
Now I pray the my 600/4 IS "L" is not relaying on glue as well.
