If you thought getting dust inside of your lens was annoying, imagine how terrible a fly would be. That may sound like a joke, but it’s exactly what LensRentals founder Roger Cicala found inside a weather sealed Canon 24-105mm f/4 L IS recently when returned to their shipping center.
With the high volume of camera gear rentals LensRentals.com handles, there is bound to be some interesting things that come across the bench. We all know that there is no such thing as a completely sealed lens, but I never thought something as large as a spider or a fly could manage to get in. As you can see below there is actually quite a large space for something to find it’s way inside the lens, despite it being weather sealed. All the more reason to diligently keep the back cap on your lens when not in use.
Once inside the barrel of the lens this little guy was able to wedge himself between a couple of the innermost elements. This made retrieval of the insect more of a full blown lens surgery, lasting upwards of 4 hours. This included full teardown of the autofocus system and removal of the inner barrel. The fly was then extracted using needle nose forceps. The elements were able to be cleaned from this point as well. Due to the extensive teardown the lens had to be optically calibrated and recentered to ensure sharpness.
Interestingly enough the fly had very little to no effect on image quality and was a challenge for the Lens Rentals team to photograph. Quite the set up was needed to even get a photo of the culprit. To see how they managed that and the rest of the images head over to LensRentals.com
[Via LensRentals]
"We all know that there is no such thing as a completely sealed lens, but I never thought something as large as a spider or a fly could manage to get in."
The sealing is relative to the front, sides, and rear gasket that you can see around the edge of the lens. Once inside it's "wide open", as you can see through the rear opening.
"All the more reason to diligently keep the back cap on your lens when not in use. "
Do people actually NOT put a cap on a lens when not in use?
"Dude, it's a rental"...
I think an interesting takeaway is that they weren't able to get the fly to affect the image quality. It just goes to show you that all those rumors of dust in your lens affecting your image quality are bullshit.
They proved that one a while back with decent pictures from a lens with a broken front element... http://www.lensrentals.com/blog/2008/10/front-element-scratches
I shattered my filter shooting gymnastics once and it became cross threaded. I had to keep shooting and aside from a few lens flares you couldn't tell at all.
If it was a lot it could affect contrast and light transmission, but what you typically find in most lenses is negligible.
I'm sure there is a Photoshop plugin for fly correction.