EOS 30D Strange (shutter?) artefact problem

someone else here had the same problem before. I believe the shutter was the issue. can anyone remember? I am sure the vets will remember. This person had the same crescent moon light thing like your pictures showed. I think at the end, it needed repair.

Looks like a bad shutter to me. Same symptom as other bad shutters.

Yup, based on responses in previous threads about the same problem, your shutter is broken and needs repair.

Conceptually, a focal plane shutter is a single device which progressively and in a straight line exposes the image (as the first curtain moves) and ends the exposure (as the second curtain moves). And in the old days of horizontal-travel focal plane shutters, that was indeed the case, at least for some cameras. But to achieve higher maximum X-sync speeds, the shutter should travel vertically, since it has a third less distance to travel to do so. Since there isn't room above or below the film/sensor plane to hold the entire shutter in this case, modern vertical-travel focal plane shutters are made out of multiple (usually 4) segments; each segment is now only a fraction of the size of the frame, so the segments don't take up much space above or below the frame. Machinery is required to make the edge of what's exposed and what isn't move as if the shutter were a single, all-moving object.

What you're seeing is that some of the blades are damaged, or the machinery that's supposed to make them move in sync isn't working properly. I don't know which, but either way, it's not something the average user can fix for themselves. It requires repair.

I posted the same problem on photo.net less than two months ago. I wound up sending my 30D to a Canon service center where they replaced the shutter mechanism. Fortunately it was still under warranty. Here is a sample image I included with that post:

http://www.photo.net/photodb/photo?photo_id=5837158

When I called the service center to arrange for the repair, I was somewhat surprised that the technician was not aware that this has become a fairly common problem, at least with shutters in Canon's APS-C sensor size cameras. As I researched the problem further on photo.net and other websites, apparently this has been happening in everything from the Digital Rebel to the 30D. I saw at least a dozen examples of this failure, and three of them were posted within a few days of each other on photo.net (Mine included). I raised the question at one point of whether this indicates some pervasive problem with the shutters in this line of cameras, but the "powers that be" didn't seem to think so. Still, it seems an unusually high rate of this exact same failure to me.

Oh, by the way, one of the posts I saw on this problem was from someone who also delayed having the shutter repaired. He finally suffered a catastrophic shutter failure with the blades getting all mangled and scrunched together. So I advise anyone experiencing this problem to get it taken care of ASAP.

joel,

thats right. You were the poster from 2 months ago. I remember that crescent moon pic now. Looks like Canon got you all fixed up.

I remember that post as well. Glad you managed to get it fixed.

If you open the back of an EOS film camera you will see that the shutter curtains are moved by a linkage that rotates about a pivot. I believe the curtains actually travel vertically (the evidence is the shadow of the second shutter curtain when trying to use too fast a shutter speed with studio strobes), but if the linkage wears it can allow a light leak that gives rise to the arc shaped artifact. If someone was feeling enterprising, photographic evidence could be provided by shooting the open back of a film camera with flash, using a variable delay circuit between the two cameras, but otherwise triggering them from the same remote.

I finally got my shutter replaced. It cost 85€ for new shutter and 50€ for work.

Here is the damaged shutter that causes this kind of problems.

You may interest.