Sensor Dust - DSLR vs Mirrorless

[pharp]

One of the arguments I often see from those not enthused with mirrorless cameras is that the sensor is more apt to get dusty - that the mirror somehow magically keeps dust off the sensor.  My OM-D requires less attention than my Canon in that regard. Is anyone aware of a thorough review/test on the subject? I'm inclined to think that the argument has no real merit.

I've seen this, but ...
http://www.dpreview.com/forums/post/50766602

[dgatwood]

Seems like a pretty good argument, IMO.  Every time you change lenses, some amount of atmospheric dust gets into the camera body.  On a traditional DSLR, the majority of it settles on the mirror because it is there.  If it isn't there, some of that dust will presumably end up on the sensor, though more of it will end up on the bottom surface of the interior rather than on the sensor.

[wickidwombat]

what happens to the dust on the mirror when it starts violently flapping around?
I would think it is remobilised and likely to end up on the sensor anyway

Personally I would place this kind of concern squarely at the bottom of and list of reasons to differentiate between the
2 systems

[rs]

It's more than just the mirror. In normal use (no live view, no video) a DSLR sensor is covered by the shutter at all times except for the duration of the exposure.

In a mirrorless camera, the shutter is only deployed to cover up the sensor just before the exposure, allowing the physical shutter to control the exposure like a DSLR, then it's off out of the way straight away afterwards. And I'm probably wrong in thinking this, but don't some mirrorless cameras leave the sensor exposed to the elements (no shutter covering it up) when changing lenses?

[Fuzzy Caveman]

And I'm probably wrong in thinking this, but don't some mirrorless cameras leave the sensor exposed to the elements (no shutter covering it up) when changing lenses?

My NEX C3 is exposed when changing lenses.

[pharp]

And I'm probably wrong in thinking this, but don't some mirrorless cameras leave the sensor exposed to the elements (no shutter covering it up) when changing lenses?

My NEX C3 is exposed when changing lenses.

OK - I'll assume you also have a DSLR - not scientific, but does your NEX have more problems with dust?

[takesome1]

More than once I have chased dust around the sensor because the mirror fans it.

The mirror isn't going to stop dust from getting in, if anything it will make it harder to clean and keep out. The mirror has the chamber up to the viewer and it is hard to clean that area. You can clean the sensor but if there is anything up above the mirror can fan it back down to the sensor.

The larger and more intricate the area inside the camera, the harder it will be to keep clean.

Less moving parts is better.

[AlanF]

When you open and close Petri dishes for bacteriology you learn to minimise any chance cross-contamination by spores and airborne bacteria by having the lid plate always pointing its inside surface down and turning over the bottom plate so that the agar is pointing down. That way, particles do not settle on the inside. I do the same when changing lens: take off the rear lens cap of the new lens and place the cap with the open end down and the lens with the open rear down; twist off the body and place it facing down; immediately put the cap on the removed lens; reassemble the camera and the other lens. I never have problems with dust on the sensor or in the rear end of the lens.(And I use the 100-400mm L and 24-105 L, which supposedly suck in dust.)

[neuroanatomist]

When you open and close Petri dishes for bacteriology you learn to minimise any chance cross-contamination by spores and airborne bacteria by having the lid plate always pointing its inside surface down and turning over the bottom plate so that the agar is pointing down. That way, particles do not settle on the inside.  I do the same when changing lens...

Ever considered carrying around a portable HEPA laminar flow hood?   

take off the rear lens cap of the new lens and place the cap with the open end down and the lens with the open rear down

Fine for most lenses, but I wouldn't recommend trying that with the 85L.

[CarlTN]

When you open and close Petri dishes for bacteriology you learn to minimise any chance cross-contamination by spores and airborne bacteria by having the lid plate always pointing its inside surface down and turning over the bottom plate so that the agar is pointing down. That way, particles do not settle on the inside. I do the same when changing lens: take off the rear lens cap of the new lens and place the cap with the open end down and the lens with the open rear down; twist off the body and place it facing down; immediately put the cap on the removed lens; reassemble the camera and the other lens. I never have problems with dust on the sensor or in the rear end of the lens.(And I use the 100-400mm L and 24-105 L, which supposedly suck in dust.)

Very good advice as usual, Alan...but doesn't it presume that you are changing lenses on a very clean surface to begin with (by laying the lenses and open body facing down)?  For instance, if you're changing them on a dusty car seat, or a pollen covered park bench or something...it wouldn't be as good as changing in a cleaner setting. 

I recall seeing a lady changing lenses at one of my nephew's soccer games a few years ago.  She obviously didn't care much about sensor cleanliness...the camera body was facing the sky, and it had started to rain.  The mirror of that camera, wherever it is now, is probably covered with water spots and no telling what else.

I too mentioned that the 100-400 could suck in dust, in another thread, and was promptly told that I didn't know what I was talking about.  But I do.  I recently bought the 24-105.  It has a bit of dust sealing at the zoom juncture, but this obviously wears out over time.  Mine is still tight, but the one I rented last year, was pretty loose.  Once it stops being tight, there's a bigger crack for the dust to get through.

As for mirrorless cameras leaving the shutter open and the sensor exposed all the time...I did not know dattt...I enjoy learning new things every time I come on this website!!

[Dylan777]

When you open and close Petri dishes for bacteriology you learn to minimise any chance cross-contamination by spores and airborne bacteria by having the lid plate always pointing its inside surface down and turning over the bottom plate so that the agar is pointing down. That way, particles do not settle on the inside. I do the same when changing lens: take off the rear lens cap of the new lens and place the cap with the open end down and the lens with the open rear down; twist off the body and place it facing down; immediately put the cap on the removed lens; reassemble the camera and the other lens. I never have problems with dust on the sensor or in the rear end of the lens.(And I use the 100-400mm L and 24-105 L, which supposedly suck in dust.)

Alan, you and I have same method here

Always one less lens cap in the bag.

[sdsr]

One of the arguments I often see from those not enthused with mirrorless cameras is that the sensor is more apt to get dusty - that the mirror somehow magically keeps dust off the sensor.  My OM-D requires less attention than my Canon in that regard. Is anyone aware of a thorough review/test on the subject? I'm inclined to think that the argument has no real merit.

I can't answer your question, but will merely note that my experience, um, mirrors yours - I probably change lenses on my OM-D more often than I do any my dslrs (I mainly use primes on my OM-D), and I've never seen evidence of dust on a photo, whereas I have a couple of times on dslrs (easy enough to remove, though).  Perhaps Olympus has uncommonly effective sensor-cleaning technology?

[ecka]

What really matters is that mirrorless camera sensor cleaning is much easier, because dust WILL get inside any interchangeable lens camera, eventually.

[infared]

When you open and close Petri dishes for bacteriology you learn to minimise any chance cross-contamination by spores and airborne bacteria by having the lid plate always pointing its inside surface down and turning over the bottom plate so that the agar is pointing down. That way, particles do not settle on the inside.  I do the same when changing lens...

Ever considered carrying around a portable HEPA laminar flow hood?   

This is my favorite response, above...too funny!

I have 2 MFT cameras and a Canon 5DIII.  I don't have dust issues with either type of camera.  I know that it makes sense that the exposed sensor on the mirrorless would welcome debris but I am not coming across anything that is monumental... i.e. that I am seeing in my images.  I use common sense when changing lenses and occasionally give the blow out treatment with a dust blower....but I do not see scads of dust that I need to PhotoShop out etc. in my images.  Do anyone really have a consistent problem with this??

[takesome1]

  Do anyone really have a consistent problem with this??

Unlike some people who only change their lenses in a sterile environment in a sealed room and always have a clean table close at hand I sometimes change lenses outside when the wind is blowing up a dust storm or it is raining. The only place to lay a lens down is on a tree stump or in the mud.
So occasionally I do get a dust particle or two on the sensor.