Dust or what?

<p>I had been experiencing shots that have what I thought were dust spots on the images. So prior to a recent interior shoot I had the sensor of my Canon 60D cleaned at Canon HQ (in Jamesburg, NJ). After receiving the camera back I went off on another assignment. But I'm still experiencing the same spotting as before the cleaning. So my question is could this be something happening with the Canon 10-22mm lens? <br /><br />See a link to the image here: http://www.tlphoto.net/_MG_5404.jpg</p>

<p>Thanks for your help!<br />Terry</p>

<p>P.S Excuse any post processing or lack there of. Saved at a jpeg 10% compression, not straightened or color corrected.</p>

<p>They seem too distinct for dust on the sensor. </p>

<p>Does it only happen with the 10-22mm lens? </p>

<p>Were you using any fill flash?</p>

<p>I'd also wonder about the lens being the factor, since in the example, the 'spots' look like reflection -- a particular problem with 'ultra-wide' lenses like the 10-22mm lens, with their acceptance of light from the sides, especially when that light is much brighter as from your window.</p>

<p>Dust on the sensor shows as sharp-edged black shapes.</p>

<p>Those are white and translucent. They're vaguely hexagonal, and the EF-S 10-22mm has a six-bladed aperture, which makes me think the source is in front of the aperture. Either lens flare - though I don't see a bright light source that would account for it - or possibly dust on the front of the lens, or on a filter that's on the lens. Could also be dust floating in the air, illuminated by a fill flash.</p>

<p>- Are you using a filter on the lens, and is it clean?<br>

- Did you use any flash?<br>

- Are there spots in every picture and are they in the same spots?</p>

<p>Check the glass on the back end of the lens, not the front end. It is easy to miss this critical area when looking for problems.</p>

<p>Not using a flash nor a filter. Yes, the spots appear on every one. Appears worse on the darker images.<br /><br />So if it's possible that its dust on the inside glass, then that would be a common problem with any lens. I don't experience this with the 24-105mm.</p>

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<p>Dust on the sensor shows as sharp-edged black shapes.</p>

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<p>Point of order, having shot with the original Canon EOS 5D, a dust catcher if ever there is one, the dust/dirt on the sensor will show up differentially depending on the aperture setting, etc.<br>

Usually as blurred spots as shown in the following illustration</p>

<p> </p><div></div>

<p>Its hard for me to think that this is just dust. I'm pretty anal about cleaning my lenses before and after a shoot and will even lightly dust them during shooting. So the emergence of these spots is pretty frustrating. And now, add in the fact that it's taking me anywhere from 5 to 10 minutes extra to meticulous clone or paint out these spots which, with up to 40 shots per shoot, is taking a lot longer than I should be spending on them.<br>

This problem really just kind of popped up the past few months but I've been using the lens for over a year. Surely it must have been dusty during that time as well. Do you think I should bring the lens to Canon and have them look at it?</p>

<p>All I've got to go on is the one picture, but I repeat that lens flare is common with these lenses, especially when you've got a bright light source like that window off to the side.</p>

<p>Did you have a lens hood on it? <br /> Hexagonal spots are almost guaranteed to be lens flare working together with the diaphragm.</p>

<p>What happens if you stop down and shoot, say, the sky?</p>

<p>No, no lens hood. Though it wouldn't be feasible for interior photography as I'm always shooting at the near the widest angle capturing the most space. Using a hood would also vignette the image slightly as well.<br>

Can the lens coating wear away of be rubbed off. Would something like that have anything to do with this?</p>

<p>My Canon 10-22 mm lens is, in my view, is one of the best super wide lenses that do not not show flare.<br>

However I have used it with the sun in the shot and seen similar of spot type flare that you have seen.</p><div></div>

<p>From your photo, I vote for internal reflection of a strong light source through the window and / or from the lamps. It seems silly, but I would opt for the lamps. Can't think there is anything actually wrong with lens; good luck</p>

<p>With the three light sources in the frame this could easily be flare, but it looks more like dirt/residue on/in the lens than anything else to me. It's just that the in-frame light sources are emphasizing it.</p>

<p>Have you checked down the throat of the lens? (ie. dismounted, and examined through the lens), if this is dust/dirt on/in it should be pretty blatantly obvious.</p>

<p>The fact that it has emerged recently supports the idea that something about the <em>lens</em> has <em>changed</em>... How do you clean it? (sometimes cleaning does more damage than it solves)<br>

Residue left on the glass from a cleaning agent may only be clearly visible when there is a light source shining through it (such as in your image), but you should be able to detect it's presence by examining the cleaned element with a light source reflected across the element. </p>

<p>Here are some out takes from this year. All are taken at the with the Canon 10-22mm at 7.1. the same aperture as the problem shot. There's one there with three different light sources florescent, tungsten, and daylight. None had the lens hood on as well. No blobs. <br /><br />I've been using this camera /Canon lens combo to shoot interiors since May. On every shoot the lighting situations are pretty much the same. This is a change that has occurred in the last two months or so.<br>

<br />Can this be condensation inside the lens?<br /><br />http://www.tlphoto.net/spots/_MG_1582.jpg<br>

http://www.tlphoto.net/spots/_MG_2219.jpg<br>

http://www.tlphoto.net/spots/_MG_2230.jpg</p>

<p>I've used the EF-S 10-22mm lens for years and it is remarkably good at controlling flare when the light source is in front of the lens. In my experience, it is more prone to flare with light sources off to the sides. The Canon lens hood (EW-83E) is designed to work at the widest angle and does not cause significant vignetting - and even if it did, it is much easier to correct than the flare you are experiencing. I would suggest you try taking some shots with and without the hood to see it you notice a difference.</p>

<p>Wouldn't I see flares in Live View? I don't.</p>

<p>"Wouldn't I see flares in Live View?"<br>

Probably not easily - however, if you can set it up in live view and detect a strong flare you could then shade the lens from strong light sources to see if changes. </p>

<p>Looks like I'll start using the lens hood religiously for now on!</p>

<p>If you use the lens hood specified for the lens (EW 83E) there shouldn't be any vignetting.<br>

However, on these ultrawides, again, the hood can't be as effective for most of the focal lengths as one made for a given fixed focal-length lens.</p>

<p>Looks like lens flare to me or perhaps something on or in the lens. Sensor spots will be lens independent and will be most visibly discrete at f22 or higher. </p>

<p>Dirty lens: spots on the filter and/or front element?</p>

<p>@Robin Smith<br /><br />No. I clean and wipe all the time.</p>