Canon 500D (T1i) erratic exposure problem
This video is shot with the Canon 500D (AKA Rebel T1i). While the footage looks great (considering the fact that I didn’t really have much light in the room, Canon really needs to give us manual aperture and exposure control for video mode on this camera because of the erratic exposure behavior in video recording mode. When I zoom in or out, you can see a quick change in brightness and hear some clicking noises when the aperture mechanism becomes erratic. Canon added manual controls for video mode on their higher end 5D Mark II in a firmware upgrade, so all the 500D owners need to unite and demand the same firmware upgrade for the 500D (Note that full manual control is already supported in still photo mode).
Regarding the movie star in this video, this cute little orange tabby was feral 2 weeks ago when he came to my house looking for mommy, and now he’s nearly doubled his weight and became tame (and spoiled).
Note that despite the fact that I set the embedded video to so called “HD” 720P mode (which is actually only ~2 Mbps meaning it’s lower than DVD quality for everything other than completely still footage), Google changed it so that you have to manually toggle the “HD” button to see the higher quality. I’m sure the bandwidth costs are killing Google so they’re hoping that most people won’t opt in on the higher quality.
Update 7/26/2009 – This guy hacked a Sigma lens to do manual aperture.
Update 7/27/2009 – This problem appears only when I’m using the Tokina 28-70 2.8 lens, which happens to be my favorite lens as far as optics and zoom characteristics are concerned. It doesn’t appear on the 18-55 USM/IS 3.5-5.6 Canon lens that came with the Canon 500D camera, nor does it happen with an older Sigma 70-300 macro-capable lens. Also noteworthy is I can pretty much shoot ants with the 300 mm Sigma. And because the resolution demands of even 720P and 1080P video isn’t that high compared to still photography, I can pretty much use any lens with great results.
There is a petition. Hopefully they will listen. http://www.petitiononline.com/firm500d/petition.html
Manual aperture in video mode can be “forced”. In AV mode, dial desired aperture then press the lens release button as if you were going to remove the lens. While holding the button in turn the lens barrel slightly as if removing it and watch the LCD. When the aperture value changes to F00 stop. You have disconnected the lens to body contacts and the camera can no longer communicate with or control the lens.
The selected aperture will remain in effect even after turning the camera off and back on again.
Now turn the mode dial on top to “movie” mode, the LCD will display a warning to insure a lens is attached (remember, body cannot access the lens and no longer “knows” you still have a lens attached), this warning can be ignored and you press the video start button to flip the mirror up and you have “live view” for video.
Focus is manual only, so be sure you have the selector switch on the lens set to manual. The aperture you have selected will not indicate what it is so you have to mentally remember what you set, camera will set shutter and ISO to get you exposure.
You have an exposure “lock” in video mode, it is the ISO button on top and once you press it the lock remains until you shut off the camera, or until you “lock” on another scene. In “lock” mode you can bias the exposure two stops under and over with the AV button above the video start button. Hold it down and turn the control wheel.
This all may work better with 2.8 and faster lenses. I use the Canon 50mm F1.8
A tutorial video about this is on vimeo at: http://www.vimeo.com/6266026
Hope this info helps.
P.S. I have a yellow tabby that moved in with us, seems to have been on her own twice that I can find out about. She has “bonded” to me so tight it is scary. I can’t get her to play hardly at all, she has no front claws so I guess she’s been pretty badly traumatized in the past.
I’m not a “cat” person although I’ve always respected them. More a “dog” person, so I keep telling her she’s the funniest looking dog I’ve ever had. She is very sweet natured and very “mannerly” and I’ve become attached. I enjoyed watching your video.
Bruce Foreman