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I've recently upgraded to the full-frame sensor Canon 6D and am used to using Canon's Rebel series cameras with the added Magic Lantern firmware add-on hacks. I have a question about the auto-exposure-bracketing (AEB) quirks of the 6D.

AFAIK, best practices for capturing "tack sharp" images is to use a tripod, remote trigger, mid-range aperture, and use the camera's mirror lockup delay feature. I was able to do this fine on the Rebel series cameras--once the AEB series was triggered remotely, the camera would lock the mirror, wait about a second, expose, and repeat the process through the series of bracketed exposures.

However, on the 6D (firmware 1.1.6), the default AEB behavior is for the camera to require each exposure to be manually triggered (either remotely or using the shutter button). After searching online, others acknowledge this problem and say the solution is to turn on Live View before triggering the bracketed series. However, in that configuration the 6D slaps through the exposures as fast as possible using just the mechanical shutter (the mirror doesn't move during Live View).

While this is better, it's still not "ideal" insofar as the slapping shutter could very well be introducing vibration and increasing movement/shake as more exposures are taken. I could feel the slight vibration when placing by finger on the camera while it was going though the exposures.

Using the Magic Lantern AEB was a little better. Outside of live view, it did run through all AEB exposures, but didn't honor the mirror lockup after the first exposure. In Live View, it did run through all AEB exposures quickly, but did give a slightly longer delay between exposures than the native Canon firmware.

Given these limitations and default behaviors, is the camera shake introduced by the slapping shutter in Canon's default firmware enough to notice or worry about (I haven't noticed a difference in a few tests, but my test conditions weren't lab-quality). Have others figured out a better method of getting tack-sharp AEB images with the 6D?

  • Someone recently tested the Canon's AEB camera shake (dpreview.com/forums/thread/3869438) and found that it does indeed happen. Thus far, I've found that the best automated method is to use Magic Lantern (ML) to direct the AEB series, and set it to "auto-detect," then while in live-view, start the AEB series. ML auto-detect introduces a healthy delay between each exposure, perhaps enough to allow the vibrations to settle. Of course, manually remotely triggering each AEB exposure with mirror-lock-up enabled will keep the camera from vibrating (assuming your delays are sufficient). – Jon Paul Vivere Jul 10 '15 at 15:00
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is the camera shake introduced by the slapping shutter in Canon's default firmware enough to notice or worry about

All AEB does is to set up a sequence of 3 shots with different exposures. Camera shake between exposures won't affect your images. Camera shake during a single exposure could obviously be a problem, but it's no different than when you're using the continuous drive mode. In particular, AEB doesn't say anything about shutter speed except that in some cases it'll use a slower shutter than what you have selected to increase the exposure in the brighter bracketed image. You can use AEB handheld just as effectively as with a tripod, provided of course that you're shooting at a speed that allows hand holding.

I'm not sure how Live View makes a difference in how the camera shoots with AEB: on my 6D, you have to trip the shutter manually for each AEB shot whether or not you're using Live View. Perhaps there's a setting (other than continuous drive) that will get the camera to shoot all three exposures automatically?

With all that in mind, the cases where camera movement might be a problem with AEB are pretty much the same cases where it'd be a problem without AEB: relatively long exposures. Here are some strategies that might help:

  • Shoot in shutter priority (Tv) mode, where you can set the shutter and let the camera vary the aperture to change exposures.

  • If shooting in aperture priority (Av), adjust ISO to allow a sufficiently fast shutter even at the longest exposure in the series.

  • Use a sturdy tripod.

  • If you're shooting at a shutter speed where you feel it's important to let the camera settle between shots, use a remote shutter release. A wired release is fine, but the 6D has built-in wifi and an app that lets you trip the shutter from your smart phone, so your "remote trigger" is always close at hand.

  • Use lenses that have image stabilization to counteract minor movement.

I haven't noticed a difference in a few tests, but my test conditions weren't lab-quality

Maybe you're putting the cart before the horse. I don't use AEB all that often, but I haven't noticed any problems with AEB images either.

  • Thanks...It appears that a moderator edited my posting title (at minimum), and of course, I'm not concerned with camera shake "between" images as the moderator worded it. I'm just concerned with the effect the rapid shutter 'click-click-click-click-click' has on camera vibration during the AEB series exposures... Thus far, the best procedure I've found is to use mirror lockup, 2-sec delay, Live View, and let Magic Lantern run the AEB series, since that at least puts a bit of delay between the AEB shots, while automatically executing the entire AEB series. – Jon Paul Vivere Jul 9 '15 at 21:47
  • FYI, you're free to edit the title if it doesn't express what you meant. It doesn't look like anything else was changed. – Caleb Jul 9 '15 at 21:52

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