Did I mess up?

Didn't know not to do this but I cleaned the mirror of my 30D with lens cleaning solution and lens cloth. Did I do any harm? There does not appear to be any scratches on it by viewing it directly or through the view finder and camara functions fine.

If you don't see anything wrong with it then don't worry about it. I've used a micro fiber cloth on mine and its fine.

Take Care,
Cheers, Patrick

Thanks, I have read on other threads here that the mirror is very sensitive and not to touch it. Didn't realize that at the time and was trying to clean dust off of it that showed up in the view finder.

In the future use an air blower such as this: Giottos Rocket Blaster

There's a lot of myths and paranoia about cleaning the mirror.
Yes, it is sensitive but giving it a gentle wipe with a clean soft cloth (or something similar) won't suddenly cause your camera to self destruct.
Neither will it cause the world to end or the sky to fall in or any of the other doom and gloom that gets perpetuated on the interwebs.
If that was the case, I would have had to replace mirrors on a regular basis on every camera I've owned since the 1980's.
In a pinch I've used a tshirt more times than I can count.
Using a bit of care and and a common sense approach you'll have no problems.

I've had to do it a couple of times. Most recently a drop of rain landed on my 5D's mirror when I was changing a lens. No amount of blowing with a rocket was going to remove a water mark.

I used lens cleaner + microfibre cloth/lens tissue. Don't press down or you can send the mirror out of alignment, and then manual focus won't work properly any more.

IMO if it only needs a blast of air to clean I would not go further than that.

Be careful and you are fine. There are those that say don't touch and clean the focusing screen too, but again, be careful and you will be fine. I use microfiber "q tips" on the mirror and focus screens, along with very small amount of distilled water. After all is cleaned, and put back, a quick burst of air will remove any remaining fibers, if any.

There are too many scaredy cats on the boards.

stock28 wrote in post #13521711
was trying to clean dust off of it that showed up in the view finder.

Dust on the mirror doesn't usually show up in the viewfinder as it is way out of focus. Usually the dust is on the focus screen, either above or below it. There is no real need to risk the mirror by cleaning it, at least not more than using a rocket blower.

I had a couple of bad dust and fluff particles on my 5D2 mirror, I could see it in the viewfinder but it wasnt showing on the pictures, I used a microfibre cloth and lighty wiped the mirror and have had no problems since. The camera still works as well as ever but now I can see what im looking at cinstead of a fluff ball.

As long as it still focuses right, you should be okay, but I wouldn't make it a practice

Thanks, all works well and I'll leave it alone from now on.

Having some training and experience with camera repairs, one of the most common user mistakes is damaging the mirror and/or focus screen. The repairs can be expensive and the specks on the mirror or focus screen do no actual harm, are merely a nuisance and will not show up in your images (the mirror is flipped up out of the way, covering the focus screen during exposure). So it's a somewhat senseless and expensive mistake. That's why I normally suggest leaving it alone and handing it over to a pro to clean. It's simply safer doing that.

In general, learn to properly clean your sensor and lenses, and leave it at that.

But, yes, mirrors and focus screens can be cleaned too. And they sometimes need it. I have my cameras serviced periodically and screen/mirror cleaning is always a part of that. I have on rare occasion cleaned something particularly nasty off a focus screen or mirror myself, too... But normally, in between regular servicing, I won't do anything more than give it a puff of air and just live with the minor inconvenience of more adhered, small particles .

One thing in particular to watch out for in there is the light seals that can starting to break down and failing. Those seals are usually good for 5 or 10 years, but might fail more rapidly if the camera is often used in hotter environments. Also those seals can be damaged when doing self-cleaning, or might be loosened if the adhesive is dampened with some sort of cleaning fluid. Often light seals going bad show up as the open cell foam crumbling and shedding particles and/or the adhesive that holds them in place leaving black smears around the edges of the mirror. Worst case, the mirror might stick in the flipped up position. If you see any of these things, take the camera in to have the light seals replaced. The mirror and focus screen will be cleaned at the same time. (Note: some or most cameras also have some internal seals of the same materials, which quite likely would need replacement too if the mirror seals are failing, but require disassembly.)

And, because "q-tips" were mentioned above, please never use standard cotton Q-Tips (aka "cotton swabs") - such as you can commonly buy at your local pharmacy or grocery store. This is one of the first things they teach camera repair techs, to never use these inside a camera. They shed tiny, tough cotton fibers that can jam and destroy a cameras shutter and other mechanisms. There are better/safer swabs made for the purpose, that don't shed fibers.

If using any sort of cleaning fluids, you have to be very careful, too. The focus screen is made from optical plastic and can be "melted" and damaged by some strong cleaning fluids.

Finally, if you must clean it yourself, in particular don't use cheap paper "lens tissues" on focus screen or mirror (or lens, or sensor). Paper that's made from wood pulp often contains minerals that can all too easily scratch these delicate surfaces or coatings. There are "optical" papers and wipes (Pecs are one brand) made from rag or other materials, that are much safer to use and less likely to scratch mirrors, focus screens, digital sensors and lenses.

I use microfiber q-tips. I make my own, but you could use VisibleDust Focusing Screen Swabs without issue.