I was just importing some footage from my xl1s and i noticed the four edges faded. Kind of like there was some sort of shroud showing up in the picture. So i didnt some tests with and without the stock shroud and it didnt seem to make a differnce. So then i went on to testing some more things on a white erase board and noticed that the whole imaged is like hot spoted, the center is bright white, then it fades out to the edges. Is that a common thing? There are some other weird things that happen that are hard to explain.

I was just wondernig is this a natural thing with optics or what. If you want i can take some screen captures to explain what i mean.

Thanks a lot,

Mike Waddick

Doesn't sound right.Do you have your setup levels at default?Is this stock lense?
Do the zebras show even and correct exposure?

The levels were at default and it is a stock lens. I started looking through my footage its completely noticeable. When i use zebras it does show that the center is more exposed then the edges, but its really hard to tell.

I took some screen captures and also a small video of whats happening. its not white balanced but you still see what i mean.

http://www.atmosphericentertainment.com/xl1/test2.jpg

http://www.atmosphericentertainment.com/xl1/test3.jpg

http://www.atmosphericentertainment.com/xl1/test4.jpg

Here is a short video that is pretty compressed, but you still get the idea of whats happening.
http://www.atmosphericentertainment.com/xl1/testmovie.wmv

Other things i have tried are removing the shroud, the UV filter but its still there. It seems as though when you zoom in it goes away alittle, but its still present.

Thanks a lot,

Mike Waddick

Has the camera ever made the trip in to a service depot for cleaning? If you were to email Canon service and describe the symptom, they might be able to recommend a fix. The soft vignetting you are experiencing as shown in the wmv looks like the effect of a step down ring with a filter attached. This could also be at the lens connection. Perhaps you can borrow a different lens and perform a comparison. If the trouble is identical, then explore the idea of having the body serviced.

did you ever solve the problem?

my XL-1 "kit" lens seems to have the exact same problem at wide-open apertures - i know that these small CCDs have problems with apertures lower then ~f4, but the vignetting is too intensive. i just stop the lens down to f4,4 or narrower and it sort of fixes the vignetting.

also, lighting seems to effect this phenomenon a great deal. how did you fix the problem? a new lens or did Canon service the old one?

It is the nature of ALL lenses to have some light fall off at the edges/corners especially when wide open. For most common types of image content it not noticed, but with a blank field (e.g., a white board) image the corner fall off is very noticeable.

See http://www.vanwalree.com/optics/vignetting.html for an informative discussion of this.

i knew that - but it seemed too intense.

it still didn't bother me that much - a week ago i was shooting this "fashion show" and there really wasn't much light to work with. the ~f2 setting and extra gain worked around it and i got great footage. you're right, the vignetting doesn't really show when shooting these kind of scenes

so you're saying it's completly normal for the XL video lens to show so much vignetting? it's not a problem then, thanks

It is normal to see some vignetting at the corners with the normal lens when shooting a flat, white screen in auto mode (so that the image is not totally washed out corner-to-corner), expecially when wide open. HOwever, not having seen what you have, I cannot say whether or not your situation is within normal limits.

check out the video of the author of this thread. mine is exactly the same, but it highly depends on the lighting conditions - sometimes it's more, sometimes less intensive.

As Don said, avoid shooting wide open. Lenses typically exhibit more vignetting at wide apertures.

Looks about like what I would expect for wide open.

that's all i needed to hear :)

thanks a bunch, Don