I'm not sure if this is a 40D or Canon problem, or simply specific to my camera. My new 40D consistently underexposes by a full stop. Even for a very evenly lit scene, the camera will tell me that the exposure is correct, but after pressing the shutter and looking at the histogram, it is all bunched up to the left. If I 'over-expose' (according to the light meter) by one full stop, then the actual exposure is right on.
This even applies to 'Auto' mode. Not that I use Auto often, but it would be nice to be able to hand the camera to someone and have them take a well-exposed shot. Also, it doesn't really make a difference what metering mode I am using.
My guess is that the light meter is simply not metering properly. Does anyone know if there is anything that can be done about this? I hate to send back to Canon for servicing, as that can take several weeks... Thanks for any input...
Posted by John Mumaw on January 29, 2009 at 5:24 PM
Are you using evaluative metering? Have you tried shooting the same subject using the different exposure modes (evaluative, centerweight, spot)?
My 40D exposes very well and I would be very concerned if it under/overexposed every image a full stop. You may very well need to send it in.
Shouldn't be more than two weeks from the time you send it in 'til you get the camera back, especially if you visit 'Repair Request' at the Canon website and use fast shipping.
Posted by Phillip Noll on January 29, 2009 at 5:25 PM
You didn't accidentally set exposure compensation at -1 stop did you? I have set it at -1 stop and then forgot about it and ruined a bunch of later shots that way!
Posted by Steve Foss on January 29, 2009 at 5:40 PM
Daniel, there should be a function in the menu that lets you clear all camera settings. Try that and see if it doesn't fix the problem. That happened a couple times on my 30D and I never did figure out what button I'd pushed to cause it to underexpose (it wasn't EC). Clearing the camera settings took care of it for me. Might for you.
Daniel - It is quite possible that the cameras meter is not calibrated correctly. Shortly after I bought my 40D, I got wiped out by a big wave at the beach, ruining my new camera. I sent it in to canon to see what they could do. It ended up being cheaper for a repair than to buy a new camera - barely, but thankfully. After I got it back from Canon I noticed It was underexposing severely. Between 2 and 3 stops under. I sent it back again, and they fixed the issue - acknowledging their mistake. They said the repair tech who did the work must not have followed the proper procedures to re-calibrate the light meter.
If you do send your camera in, I would highly suggest that you call and talk to someone first. I have been able to persuade them to rush my equipment through just by chatting up and laying a little B.S. to the repair center people. Especially if it is still under warranty. My entire turn around time for the second fixing of my 40D was only a week from Oregon to SoCal and back.
Thanks for the advice, Aaron. I am headed to the Big Island (Hawaii) in a couple of weeks and would be bummed if I didn't have the camera, but will probably send it in right after that trip if it still isn't metering right...
Dan
No problem, Dan. Hopefully things work out for you.
I actually toughed it out for a few weeks with a messed up light meter. I had a trip planned, and didn't want to be without my camera. I just got used to the inaccuracy, and shot everything in full manual mode, relying on the histogram at all times.
I never thought about it at the time, but try turning on live view as well as the real-time histogram (press info during live view until it shows). Also turn on the live view exposure simulation (C.FnIV #7). See if the simulated exposure matches what the histgram is telling you. For example - Turn cam to manual mode. Pick any aperture. Adjust the shutter speed until you lose highlight detail in the live image. Does the histogram show clipping at the same time as the live image looks blown out? Or earlier, or later? I'd be curious to see what happens.
Discussion
7 repliesThis even applies to 'Auto' mode. Not that I use Auto often, but it would be nice to be able to hand the camera to someone and have them take a well-exposed shot. Also, it doesn't really make a difference what metering mode I am using.
My guess is that the light meter is simply not metering properly. Does anyone know if there is anything that can be done about this? I hate to send back to Canon for servicing, as that can take several weeks... Thanks for any input...
My 40D exposes very well and I would be very concerned if it under/overexposed every image a full stop. You may very well need to send it in.
Shouldn't be more than two weeks from the time you send it in 'til you get the camera back, especially if you visit 'Repair Request' at the Canon website and use fast shipping.
John: I have tried using the different exposure modes, but get underexposed with all of them.
Phillip: I am fairly sure I didn't set the exposure comp at -1, but its possible! I will check that tonight for sure...
Steve: If that doesn't work, I'll try clearing the camera settings, although that's a bummer, since I have set some things the way I like 'em...
If you do send your camera in, I would highly suggest that you call and talk to someone first. I have been able to persuade them to rush my equipment through just by chatting up and laying a little B.S. to the repair center people. Especially if it is still under warranty. My entire turn around time for the second fixing of my 40D was only a week from Oregon to SoCal and back.
Hopefully this helps. Good luck.
Dan
I actually toughed it out for a few weeks with a messed up light meter. I had a trip planned, and didn't want to be without my camera. I just got used to the inaccuracy, and shot everything in full manual mode, relying on the histogram at all times.
I never thought about it at the time, but try turning on live view as well as the real-time histogram (press info during live view until it shows). Also turn on the live view exposure simulation (C.FnIV #7). See if the simulated exposure matches what the histgram is telling you. For example - Turn cam to manual mode. Pick any aperture. Adjust the shutter speed until you lose highlight detail in the live image. Does the histogram show clipping at the same time as the live image looks blown out? Or earlier, or later? I'd be curious to see what happens.