# 5D Mark II ~Help!~ order of metal shims over superimposed plate?



## R1-7D (Oct 25, 2012)

I disassembled my 5DII to get some dust out from behind the focusing screen and the superimposed indicating plate by the prism. There are two metal shims between the focusing screen and the SI indicating plate - one a gold colour and the other silver. 

When I took it a part I swore the gold shim came out first and was closest to the focusing screen, and the silver spring second and closest to the SI plate. 

Now I am not too sure...

My questions are:

*1) Does anyone know the correct order of them?, and

2) Does the order even matter as long as they are both there?*


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## R1-7D (Oct 25, 2012)

So I have seen elsewhere on the internet that there are three shims in the camera. I am 99% positive mine did not have three. There is no way I would have misplaced a part. 

The camera was bought brand new in June too. Is it possible that Canon only used two shims, or have I REALLY lost one?

Like I said, I was very careful not to misplace any parts. I was just in a hurry and didn't take the proper notice of the order the shims go in.


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## R1-7D (Oct 25, 2012)

Bump. Anyone?


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## neuroanatomist (Oct 25, 2012)

Sorry, I know that this particular ship has sailed, but Canon most likely would have cleaned it for free under warranty.


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## Mt Spokane Photography (Oct 25, 2012)

The color likely indicates the thickness of the shim. Its how the thickness of many shims are indicated that I've seen in use.

The thickness and number of shims will likely be different for different bodies, since what they are doing is allowing for tolerances in production in order to get the image on the screen in focus at same time the image on the sensor is in focus for that particular camera.
The shims are used as required on all bodies, if one is not needed, then there is none. Its part of the factory calibration process.
The order of installation should make no difference, but the thickness does.


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## R1-7D (Oct 25, 2012)

Thanks for the response. The gold Shim is definitely a little thicker than the silver one. I put the silver one in first and the gold one in second. The gold one is closest to the focusing screen and the silver one is closest to the superimposed screen. Does that sound about right?


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## Mt Spokane Photography (Oct 25, 2012)

R1-7D said:


> Thanks for the response. The gold Shim is definitely a little thicker than the silver one. I put the silver one in first and the gold one in second. The gold one is closest to the focusing screen and the silver one is closest to the superimposed screen. Does that sound about right?


It should not matter. What matters is the total thickness of all the shims togather. If 1.2mm is needed, then you would have a 1 and a 0.2 shim. if 1.4mm is needed, then a 1 plus two 0.2mm shims, for example.


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## R1-7D (Oct 25, 2012)

Thank you again for the response!

So am I understanding you correctly too in that each camera will be calibrated differently, so to speak, and some 5DII's will have more shims than others depending on how they are manufactured?


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## Stephen Melvin (Oct 25, 2012)

R1-7D said:


> Thank you again for the response!
> 
> So am I understanding you correctly too in that each camera will be calibrated differently, so to speak, and some 5DII's will have more shims than others depending on how they are manufactured?



Pretty much. Things get even more complicated when you have a 100% screen, like the Mk III. Lots of hand calibration. 

The dust you saw was probably on the bottom of the focusing screen in the first place, btw.


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## R1-7D (Oct 25, 2012)

Stephen Melvin said:


> R1-7D said:
> 
> 
> > Thank you again for the response!
> ...



Thanks!

I feel so much better now. I can go out and use my camera and finally enjoy it after all this useless tinkering!


One last question, though: Is there any particular symptom that will show to make you want to add or remove an extra shim?


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## Mt Spokane Photography (Oct 26, 2012)

R1-7D said:


> Stephen Melvin said:
> 
> 
> > R1-7D said:
> ...


If you manually focus, and when you are certain the image is sharply focused, but the image is not in focus, that indicates a problem. Once its properly calibrated, if it goes out, something is wrong and it needs to go to Canon, they do not go out unless something has broken.
Normally, a change in shims is only required when a different screen is installed, and its a slightly diferent thickness. This seldom happens unless you were to install a 5D screen in a 5D MK II, for example, and then they normally come with a shim.


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