Handling dirt on sensor and/or lenses

[Chrissie]

Intended as a start of a collection of tips and tricks on this topic:

If you have a mirrorless, exchangeable lens camera, then sooner or later you will likely be affected by this: dust (or worse) spots, specks or stains that become visible on your pictures.

How to detect: well this part is easy. They become visible when reviewing pictures at or near full resolution on a computer screen. Typically as dark spots against an otherwise bright, or at least uniformly colored background.

Are the particles on the sensor, or on the lens? this is not quite so easy to differentiate. And there may be cases when both components are affected.

I typically exchange lenses first, in order to see if the problem is confined to one lens, and does not occur with the other. If the problem persists regardless of lens, then that's a strong indication that the problem sits on the sensor. If the problem only occurs with one lens and not with any other, then this is again a strong indication that the problem sits on this one lens.

For instance, I identified a lens problem with my 100-400GM by mounting it to the body, setting it to aperture priority and setting the aperture to the smallest possible value (38), then aiming at a bright, cloudy sky: spots then became visible in a 5 o'clock position of the EVF. Up to this moment, the cause could have been the sensor, or the lens. But when I turned the zoom ring towards 400mm, the spots sort of moved a little towards the center, still at the 5 o'clock direction, and became more blurred. That's when I figured it was a lens related problem.

What to do about it: of course, you can always resort to a professional cleaning service. But this is both costly and, at least in my case, time consuming. As I'll have to bring it in to the dealer who is situated a 45 minutes drive away and leave it there for a couple of days. Then later I'll have to pick it up again. So for me this is not a sustainable option, considering my typical usage pattern: which is mostly outdoors, hiking through the alps, and exchanging lenses quite frequently along the way. So, the risk is always with me.

But I've had good results with these do-it-yourself cleaning swabs. And, against their expressed recommendation, I'm still on my first swab as I keep re-using it as long as it works well. What I've found out though is, that it's worth while to well lubricate the swab, before doing the cleaning. I'm saving on the swabs themselves, but am generous on the cleaning liquid.

As far as the 100-400GM is concerned: the problem was in fact sitting on the rear end of the lens. And it was visible when using a good glass-glass magnifying glass when looking into the rear end at slightly varying angles and having really bright LED lights. (I'm 60 years old and my natural vision has deteriorated with age, so I' taking every help I can get hold of).  Apparently there is a flat protective glass inside the rear end to keep dirt from getting really deep inside the lens. Well done, Sony! So I was able to use the same swab that's intended for sensor cleaning to also clean the rear end of the lens, too.

Maybe your mileage varies, and maybe you'd like to share your experience, too.

[LiveShots]

I use the clean mode first before reaching for a swab. I usually remove the lens first, place the cap on the camera and point it downward before activating it.

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[martynhicks]

Try using the Kenai , Air Duster. Which is a can of compressed air to clean out dust. Be careful though to use at a distance and not get too close to the sensor as it's pretty powerful. It's a great way to clean gear before using swabs.