Sensor & Mirror cleaning

[Glyn R]

I need to clean the mirror and perhaps the focus screen on my A350. The sensor needs a clean too. I am disappointed this needs doing so soon. Any advice or recommentations. Being an ex Olympus user I have never cleaned a sensor.

[David Kilpatrick]

Do not try to clean the mirror. There is no way it should ever get dirty, and they are very fragile - never use a cloth or any liquid on the mirror. Just use a Giottos Rocket Blower, a Hama Dust Ex, or a similar large bulb air puffer. Try this first for the sensor too. How do you know the mirror needs cleaning? If you see specks in the viewfinder, it is the focusing screen, not the mirror, which has got dust on it. Again, it can not be cleaned except by air blowing. I have only cleaned KM/Sony sensors twice in around 30,000 total photographs between five bodies, and then just to get rid of one or two faintly visible dust spots which would not shift. I use Dust-Aid sticky pads, of the type labelled for CANON which can be used on ti-ox coated cover glasses like that in the A350 (regular Dust-Aid pads should not be used). I have found these - using no fluids - very efficient at grabbing what spots were there.

David

[Glyn R]

I realised after a little thought that the dust was on the focus screen. It would not really be visible if it was the mirror. I have removed spots fom the sensor with a blower. I guess I panicked, in 4 years of Olympus ownership I never had a single sensor spot. I am not sure why the focus screen should attract dust. I never cleaned one on any SLR before in about 30 years.

[alphamember]

I see dust on the A100 sensor and now the A700 sensor all the time. In the beginning it made me nervous because I was afraid for cleaning it.
Then one day I have encouraged myself. After reading about all the methods there are and the results they give, I use now the following methods once a week (dry cleaning) and once a month (wet cleaning).
It has become a routine and it is a 2 minutes job now. I did some 50 wet cleanings on my A100 without any problem yet.
A have some of those brushes (not the blower ones): one for the sensor and one for the inner compartment (focusing screen, mirror). For non smear dust it works just great as it collect the dust particles through the static electricity of the brush hairs.

But here's my statement and my experience which I never saw mentioned by anyone yet. For comparising: after washing your cars windows (and even if you left your car in your garage), then after a week you will find some smeary film on your windows (even without any trip making). You can see it clearly when you clean a part of the window and you look at this part with some light shyning.
The same happens with your sensor, focusing glass (just a peace of plastic) and mirror. They all become smeary over time just from air pollution. So it's not only a dust problem.
I can asure you that taking a shot of a sunset before and after a wet cleaning of the sensor is quite a difference. The halo effect around the sun is much more visible before the cleaning and is even total gone after the cleaning. I was thinking about this because after about six months (without cleaning) I couldn't get a clear sunset shot anymore, all with the same lenses. There was always some hallo effect around the sun or other very bright sources.

I made me some pads and ordered some 100% (pure) methanol in my hospital's lab. After some practice on a piece af glass I did the sensor cleaning with perfect results. It leaves no traces and evaporates instantly. With the same used pad and fluid I clean the mirror and the focusing screen (I take this screen out of the cam's house because then I can clean it at both sides. Again after a few months there is some difference in view clarity. The smeary film comes little by little so you aren't aware of its presents till you do a cleaning.

I have once opened a defective lens and even on the inner glasses of that lens there was some smeary film as we found through the microscope in our lab when we cleaned one half of the glass and one half without a cleaning.

Be aware of leaving your cams and lenses in a hot car because heat has a multiplicator effect on air pollution. You can test it by yourself by parking your car outside in the sun or inside in your garage for about 14 days (not affected by rain of course and with no trips, just static). You can see the difference for yourself.

I hope my experience has some value for you all.

regards

Rob