30D Mirror has drip marks after a rainy shoot

I opened up my 30D to change lenses and noticed the lens has a big white colored

streak on it. This is after a rainy day of shooting last weekend where the

camera might have gotten wetter than it should have (is this possibly from

condensation?)

 

I have seen a few posts regarding fingerprint marks on the mirror, but wondered

what the best way to handle this is - the fingerprint post suggested simply

doing nothing. Any advice regarding this is appreciated.

For a start you should make clear whether its the lens or the mirror that has the streak ?

If the mark is on the mirror, and you cannot see any sign of the mark when looking through the viewfinder, don't worry about it. In theory it could affect the exposure metering and autofocusing if it was opaque.

 

The reflex mirror has a very delicate surface that is easily scratched. It can be cleaned using isopropyl alcohol and very gentle wiping with a cotton bud, but only if the mark causes a problem.

 

If it's on the lens you can clean it with a soft cloth.

 

So, if it doesn't affect you photographs leave it alone.

 

Henry

I had a couple of film cameras given to me that had dirt, smudges or finger prints on their mirrors. To clean them, I soaked a Kodak Lens Tissue in 90% isopropyl alcohol and then let the tissue fall flat on the mirror surface. Dragging the wet tissue off the mirror cleaned it well in a couple of passes. The weight of the wet tissue was the only pressure applied to the delicate mirror.

 

As mentioned above, if the streak does not affect the view finder or AF, leave well enough alone.

 

Be sure that the Isopropyl alcohol, which is often sold as Rubbing Alcohol, contains no oil additive. Some rubbing alcohols do have oil added to reduce skin drying.

The mirror's reflective metallic layer is on the front surface, very fragile, small and recessed inside the lens opening. One suggestion for cleaning a similar scanner mirror was to use a Q-Tip with a half broken stalk, so that it's just dangling. You want to use the bare minimum of pressure.

 

Also, I wonder if isopropyl alchohol is the best cleaner. I find it very prone to leave streaks when cleaning lens filters. I prefer a cleaner supplied by my optometrist, described as "lens cleaner". I believe Kodak and few others make specific lens cleaners. Check with camera stores, and perhaps they can even suggest a pro to do it.

 

If you opt to clean it yourself, I would strongly suggest you experiment by cleaning a lens filter first, trying different solutions and applicators, to determine which is the most effective, efficient and streak free, before progressing to the deeply recessed and fragile front-silvered mirror.

Also, be careful shooting in the rain (maybe just don't). The 5D is by no means weather sealed and could get toasted by an electrical short.

Sorry, I realized when I read this again that I had called out the lens when I meant the mirror. I checked with one of my fellow classmates who has a Nikon and the same thing happened to her mirror. The ziploc bags we were using to shield our cameras from the rain were apparently not enough, and I agree that we were taking a risk being out without a camera that was weather sealed.