# Using pencil eraser to clean Camera / Lens contacts?



## J.R. (Feb 4, 2013)

Hi,

Stumbled across this in one of the Canon DLC articles earlier today - thought I'd share - 

_"Warning: do not clean lens contacts on either a Canon lens or the camera body with an eraser! It’s incredibly easy to rub off the gold plating on these contacts, and end up with data communication problems, even if that wasn’t the original source of the problem! It’s obviously a good idea to clean the contacts if a lens communication error is reported, but our strong recommendation is to use a soft, clean cloth, perhaps moistened with isopropyl alcohol if you feel the contacts are smudged with fingerprint oil or similar debris and really need a cleaning agent. Again, do not use anything abrasive, and to repeat: do not use an eraser!"_

Apologies if this has been covered before ... I've seen this for the first time!

Cheers ... J.R.


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## AprilForever (Feb 4, 2013)

J.R. said:


> Hi,
> 
> Stumbled across this in one of the Canon DLC articles earlier today - thought I'd share -
> 
> ...



Interesting....


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## Camerajah (Feb 4, 2013)

I have only used the eraser method a few times,now I use lightly damped cotton swabs for the lens contacts and lightly damped cotton cloth for the pins in the camera all light pressure a single drop of WD40,LIGHTLY DAMPED not dripping,then wipe with dry end of swab and cotton cloth,then point body and rear of lens down and blow with a hand blower-have been working for decades


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## Don Haines (Feb 5, 2013)

As an electronics technologist, who has cleaned many thousands of contacts, i agree. The contacts inside your camera or on the lens will never get very dirty or corroded. Just go to an electronics store, get some contact cleaner, spray it on a Q-tip, and gently wipe.

The pencil eraser is a bad idea.... drafting erasers work better, but you only use them when there is a considerable deposit on the contacts and you WILL remove some of the plating... no matter how carefull you are... and there is not a lot on them to start with.. You will also introduce small abrasive particles into your camera.... BAD IDEA!

I have seen corrosion and deposits so bad that I have had to use knives and sandpaper... but these are last ditch efforts to get things running until replacement connectors can be found... you will not be replacing the connectors so you have to be carefull with what you have.


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## wickidwombat (Feb 5, 2013)

yep not a good idea,

file it in the same category as using a pipe wrench to remove your lens from the body


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## Mt Spokane Photography (Feb 5, 2013)

Having worked with specifying, manufacturing and testing gold contacts for many years, its a bit of a poor situation with the tips of the contacts being used to make electrical contact. Gold is a lot like a thick paste and pushes around and smears much easier than some metals, and the pressure is pretty high on the end of those contacts. Plating the ends of the contacts is also quite difficult, thats where the gold will always be the thinest, and where gaps or cracks in the plating are most likely to occur.

You do not want a gap or crack in the gold, since you then will get dry circuit corrosion with the nickel underplate. Dry circuit corrosion cannot be seen, because it it a thin electrical insulator for low voltages. The wiping action of installing a lens will normally wipe the film away.

There are tons of inventors who have created cleaning solutioons for electrical contacts, but most of them also wipe away some gold, and in the end, ruin the contacts. They beat a path to our door, but most don't understand the issue because they can demonstrate that it cleans, but we look at the surfaces under a scannng electron microscope and can see the damage. You can also see damage by cross sectioning a part, but gold is so soft and easy to smear that only the most talented and able technicians can section and polish a gold plated part successfully. We also use x-ray fluorescent test machines to measure for proper gold thickness, but they cannot see cracks or pores.

Generally, a wipe with a smooth clean cloth is well able to clean away any dry circuit film, and it should only be done sparingly. Non aprasive cleaners are ok, but they may get into the camera body and wreak havoc. Most of the time, just removing and remounting a lens fixes the issue. The issue could originally be a manufacturing defect, but if a eraser or contact cleaner has been used, that is also a suspect. Once the damage has been done, it will only get worse, so beware, even one time can mess things up.


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## Waterdonkey (Feb 5, 2013)

I think this is an "In a Pinch" solution. 
It worked for my 7d and a 10-22mm I had. But I have to agree Clean them proper when you get home.


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## picturesbyme (Feb 5, 2013)

Microfiber (always have a few in my bags, cases) works fine.


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## Don Haines (Feb 6, 2013)

Waterdonkey said:


> I think this is an "In a Pinch" solution.
> It worked for my 7d and a 10-22mm I had. But I have to agree Clean them proper when you get home.



It's not an "in a pinch solution".... you can seriously damage the pins VERY easily.

The use of erasers to clean contacts goes with cleaning the contacts on printed circuit boards..... and you do remove the plating... clean them a few times and you can clearly see where the gold is worn away and the copper is showing. On the printed circuit board the contact is flat and easily plated.... not so on edges of materials... like pin ends. When you clean a circuit board connector the contact is over a much wider area than the tip of a pin so the pressure per square inch, and abrasiveness, is much less. The use of an eraser is destructive cleaning, I can't say it any plainer.

If you are spraying anything.... do not spray directly on the contacts as the solvent will also splash around either the camera body or the lens.... spray on something outside of the lens or the body and then use it to clean the contacts.

If you use a cleaner... you need to use something that will not leave a non-conductive residue. Things like WD40 will make electrical contact problems worse.


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