Dust inside lens body

Geekxin · Dec 15, 2014

Just noticed my Canon 24-104L has a few pecks of dust inside the lens body. I am not sure how they got there, but its noticeable in the pictures I take. I tried opening the back of the lens but that there are wires and circuits and i cant reach the inner glass where the dust seems to have settled. Is there any way to clean up or should I just take it to a Canon service center? Are there any other recommended lens cleaning service providers? Any pointers would be helpful.

Overread · Dec 15, 2014

Generally its best to send it to Canon for this kind of cleaning job since they'll also have all the proper tech to put it back together again.

That said its not al that common for small dust particles to have much effect on image quality until they are quite extensive - any chance you could share a shot or two - could be the dust (I know that front element dust is basically invisible - whilst rear-element can be more noticeable) or could be something else.

Geekxin · Dec 15, 2014

It is more visible on blue backgrounds like skies like the one below

http://i.imgur.com/Bqqtehx.jpg

imgur: the simple image sharer

Overread · Dec 15, 2014

Good news - those specks are NOT dust on the lens in any form.

It's tiny dust particles on the sensor inside the camera (or rather upon the glass filter that is right infront of the sensor). They will indeed typically show up both on a very clean/blank surface (like the blue sky) and also where you are using a smaller aperture. If you're shooting at f2.8 chances are you wouldn't see them at all even on the blue sky - close down to f13 and they'll pop right up.

Good news too is that you can clean your sensor yourself - a simple natural air blow (like a rocket blower) can be used to puff the dust off the sensor. There are also direct contact methods for both dry and wet cleaning (lots of instructions on these online as well as youtube videos). I would advise against using any form of compressed air - if you must use it then use 100% natural air (often sold as specifically for electronic cleaning). This is because most common natural air canisters are not pure air, but contain a liquid (blow some of that air on black fabric and you'll see all the flecks of chemical appear). You must also only ever use it in short bursts (people have frozen their sensor by using too much all at once).

In addition most camera shops offer a sensor cleaning service if you don't feel like doing it. It's not too expensive and generally very quick (drop it off - ready 10-30 mins later affairs)

In addition in editing you can use the "spot heal" tool to fix the dust-spots. Lightroom can also fix this (in most versions) with a similar tool.

Geekxin · Dec 15, 2014

Thanks a ton. Its a relief! I do have a sensor cleaning pen and Giottos Air Blaster. I will give it a shot with that first.

Overread · Dec 15, 2014

Good - just remember that sensor cleaning can take a while - sometimes youll be blowing the dust around inside so always hold the camera facing down and let it has a moment for dust to fall out in-between puffs. It can take several rounds to get dust out even if you're wet/dry cleaning the sensor so clean - check - reclean as needed.

Tinderbox (UK) · Dec 16, 2014

I would blow it out in a low dust area, say in the bathroom after a shower, as on a sunny day i got a shock of how much dust i was sucking in and blowing out with my rocket blower, my next one will be an new air-filter type, also keep the camera opening facing down when you blow it out.

John.

KmH · Dec 16, 2014

A sensor cleaning pen? Or a lens pen?
Don't use a lens pen.
The last thing you want is a scratch on the filter array that is actually what you clean.
The filter array is in front of the image sensor.
Digital Camera Sensor Cleaning

Geekxin · Dec 16, 2014

Yeah you are right, there is no 'sensor pen'. I had 3 pens from a long time ago, 1 for the lens, one for the view finder and 1 for the filter. Got the filter one mixed.

TCampbell · Dec 16, 2014

There are lots of tools to clean sensors... including the camera's self-clean feature.

You can remove the lens and body cap, point the camera at the ground, and invoke the camera's self-clean feature which may break the dust loose and let it fall out of the camera.

If that doesn't work, an air-blower may break the dust loose.

If that doesn't work, then I want to know what I'm dealing with before I proceed farther... I use a magnifier ("sensor scope") to inspect the sensor to find out if I've got dust, oil, etc.

A pristinely clean and very soft brush may do the trick -- a few light strokes.

If that doesn't work, then I typically resort to "wet" cleaning the sensor. This involves using "Eclipse" solution and "Sensor Swabs". Both are made by "Photographic Solutions, Inc" and can be found at most real camera stores or ordered online. Eclipse is nearly pure methanol... which means it evaporates almost immediately and leaves no residue behind. Follow instructions (there are numerous YouTube videos showing how to use it... but basically 3-4 drops of solution on the swab and a single swipe across the sensor surface. Don't risk a scratch by reusing a swab that may have dirt on it... one swipe and toss it out.

I recently learned about a new gummy/gel stick for sensor cleaning... I've not used one of these myself, but here's the link:
Sensor Gel Stick: Safely Clean Your Sensor Like They Do at the Service Center

Whenever you clean your sensor... don't be in a rush... take your time, and be gentle (don't use much pressure.) Heavy pressure just makes it more likely that something could scratch the surface.