which sensor cleaner from ebay? for my 20D

Started Sep 23, 2010 | Discussions thread
Gregory Chang
Regular MemberPosts: 283
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Re: Still my favorite sensor cleaner:
In reply to JimH, Sep 25, 2010

thanks JimH.

Your site has very good description and very helpful. Since you have done this many times, I will study it very carefully.

thanks again.

gychang

JimH wrote:

I simply breathe carefully into the mirror box so that my breath will condense onto the sensor's upper filter.

I then carefully wipe the sensor filter with a cotton swab using the condensed water from my breath as the "solvent".

That condensed water is, by definition, distilled, and also contains a trace of carbonic acid from the CO2 from your breath that is absorbed by the water. That ionizes the water slightly, making it somewhat conductive, and that helps dissipate any static charge that may be holding the dust to the sensor filter.

Condensed breath has been used for hundreds of years as the "solvent" for cleaning optical devices.

The nice thing about using cotton swabs is that they're so inexpensive that you won't be tempted to re-use them.

I open the package in a clean area and transfer them into zip-lock bags and then work from the zip lock bags. If I feel that I may have contaminated one of the bags of swabs, I just relegate them to "ear cleaning" use

The most critical thing for sensor cleaning is to avoid scratching the sensor filter. If you scratch the sensor filter, you're pooched! If you smear it with something, that can be cleaned off, so it's not the end of the world.

And the way one scratches the sensor filter is by dragging something hard and sharp (like a small particle of sand or grit) over the filter.

This can happen with any swab, be it a specially prepared one or a special store-bought sensor swab. So it's critical that you swab the sensor filter only after you've done everything you can to assure that there is no hard grit on the sensor filter.

So I try a bulb blower first. If that doesn't get the dust off, I use "canned air" (commercial aerosol cans of propellant sold for dusting). If that doesn't get it, I move on to the condensed breath and cotton swab treatment.

SOME "canned air" can be used safely if you're careful. Do not dispense any liquid! It will chill whatever it hits immediately and could crack the sensor filter! So use a partially used can, and hold it upright so none of the liquid can make it to the exit opening for the can.

Try to avoid the stuff with the "bittering agents" in it. Some of that may be harmful to you or the camera. Test the canned air on a filter, mirror, or some other optical surface to assure that it does not contain anything that leaves a residue!

Avoid blasting things too hard with it to avoid physical damage (like blowing the mirror right out of the camera - or blasting the shutter curtains out of position, etc.). Be gentle with it. In short, use common sense, and practice with the "canned air" on other objects to get a feel for it. Always do a test blast outside the camera first to assure that you're not dispensing any liquid.

The one drawback to cotton swabs is that they can leave behind fibers. But those fibers are huge and can be blown out or pulled out with tweezers if they get stuck. The hard thing to remove is always fairly tiny dust that seems to stick to the sensor filter by static attraction. The moisture from your breath and the swab seems to do a decent job of getting that.

Then just blow the camera out again with a bulb blower (or the canned air - carefully) as the final step to remove any dust that remains.

Sometimes you have to do it a couple of times, but again, the swabs are so cheap that it doesn't matter, and they're "pre-made", so you don't have any time invested in preparing them. If it takes a few tries - that's OK.

I've done this, literally, HUNDREDS of times to my 20D, and it works fine and has never done any harm. I also do it occasionally to my 40D because while the anti-dust features of the 40D are helpful, they're not 100% effective.

BUT, be advised that you COULD damage your sensor filter with ANY method where you rub it with anything. So I can't take any responsibility for what anyone else might do! If you feel comfortable with precision tasks, it should be no problem. If not, then you may want to think hard about it.

I prepared a web page to describe what I did many years ago. That page is here:

http://www.tribcsp.com/~sigma2/SensorDust01.html

Some of that data may be out of date due to the advent of newer cameras. But it's still valid for the 20D and 40D.

Again, do any of this entirely at your own risk. I can only relate what I do, and how I do it. It's always worked just fine for me.

And remember: Dragging any sand or other hard grit across your sensor filter could easily scratch it. So that's what you must avoid.

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Jim H.

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