Auto ETTR with external Flash turned on causes ETTR reach its limits

Issue #1716 new
Former user created an issue

I don't know if this is intended or even necessary to be fixed, I just noticed it.

I am currently using the first October 1st NB because every newer one since that version has a mission aperture stop indicator.

I noticed when using Auto ETTR (within its limits) and an external flash (430ex II), that the ETTR keeps cranking up the exposure stops and the abort with a message, that the limits have been reached, as seen in the attached (little blurry) video.

Comments (10)

  1. Alex

    Canon firmware keeps LiveView brightness constant (regardless of exposure settings), and ETTR relies on LV brightness to meter the image.

    I don't have an external flash, so here's a question: in Expo menu, does ExpSim turn off when the flash is active?

    (also try with the built-in flash; if that has the same problem, I can take a look)

  2. Former user Account Deleted


    I tried as you said and used both the external and internal flash.

    The ExpSim doesn't visibly turn off in the menu (says ON all the time), but it actually seems to turn off when flash is enabled.

    I attached a video with the external flash. I only had my crappy cell phone with me so it's blurry and the sound doesn't work properly, I'll explain what is going on there:

    -Camera in LV, External Flash turned off. Pointing out of a window, RAW Zebras enabled (you can see the blue Zebras on the window frame)

    -Using Auto ETTR with Double Click Halfshutter (works best for me)

    -Exposure correction +2.3 EV due to Auto ETTR

    -Zebras on the window frame are gone, then I turn on the 430EX II, LV screen stays at it was the whole time (so ExpSim still working)

    -then I hold down halfshutter to send the camera settings to the flash (E-TTL). When doing so, ExpSim seems to stop working, the LV screen gets darker....quite noticeably, the video doesn't really show it.

    -Turn off the external flash and everything is fine again. (I hold down halfshutter directly afterwards, you can see LV screen go bright and dark when the lens is searching for a focus point)

    What is not shown in the video is the use of the internal flash. I just have to pop it up with the Flash button and ExpSim immediatly seems to turn off and LV screen gets darker, no halfshutter press involved. When I close the pop up flash everything goes back to normal.

    And as I mentioned, ExpSim stays ON the whole time in ML menu

  3. Former user Account Deleted


    I wasn't shooting for quite a while now until yesterday. When I used my external Flash in LV (the 430 EX II) I still experienced that Exposure Simluation doesn't work when the flash is turned on, what is really inconvenient.

    Could somebody have a look at it please?

    The DSLR is use is a 550D, also using the latest Nightly Build.


  4. Former user Account Deleted

    No it doesn't.

    When I enable Expo Override the LV get's darker, so I have to manually adjust a slower shutter time to see something on the screen. Under- or overexposing via AV+Scrollwheel doesn't do anything.

    Under- and Overexposing via AV+Scrollwheel does work in LV with ExpSim enabled when the external Flash is turned off.

    When I turn it on an press halfshutter the ExpSim immediately stops working and the picture stays the same even if you under or overexpose.

  5. Alex

    "Expo Override the LV get's darker, so I have to manually adjust a slower shutter time to see something on the screen" => this means it's working, right?

    Of course, it will only show the ambient light, without the contribution of the flash.

  6. Former user Account Deleted


    I wasn't shooting. Just running LV. I assumed that ExpoSim would also work with activated flash for preview purposes, but it doesn't. I wouldn't mind if this would work even though the flash doesn't show (of course) in the preview.

    Just tried with internal flash, doesn't work with that one either

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