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So far, I have been taking my pictures with a Sony F717 (a dinosaur of digital photography). Nevertheless the F717 has a nice preview feature for shutter speeds. Up to 1 sec, it simulated nicely the effect of the chosen timing. So before even taking one picture I can adjust the shutter speed.

With contemporary cameras (DSLR, DSLM) I am really missing this feature. They have live view, but mostly only allow to preview the effect of exposure compensation. Some provide a preview for depth of field when in aperture mode.

  • Why do professional cameras not allow to preview (live view) the effect of chosen shutter speed?
  • Is my thinking/workflow not professional enough? Maybe a preview of the effect of the shutter speed is not necessary when doing it right.
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    \$\begingroup\$ You mean like a blurred image on slow shutter speeds? My old cellphone used to do that, and I guess my syster's Cybershot does it. I think it's because nowadays expensive cameras can boost up the ISO to make the image steady even at low shutter speeds. There might be an option to disable that in some cameras. If you can provide your camera model or brand maybe someone can help you with that. \$\endgroup\$
    – Alex
    Commented Mar 26, 2013 at 19:18
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    \$\begingroup\$ How do you preview shutter speed? If you switch to a faster shutter speed do you mean the preview in live view becomes darker to indicate how the final image will look? Or do you mean as Alex mentions above? \$\endgroup\$
    – MikeW
    Commented Mar 26, 2013 at 19:19
  • \$\begingroup\$ I mean preview in the sense of lighter/darker image. I do not need to preview motion blurring. \$\endgroup\$
    – Andre
    Commented Mar 26, 2013 at 20:54
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    \$\begingroup\$ The best way to judge exposure is to take a test shot and look at the histogram. Judging exposure by the brightness level on the screen is not very accurate, as the brightness level setting of the screen itself will affect the way the exposure looks. \$\endgroup\$
    – Michael C
    Commented Mar 26, 2013 at 21:41
  • \$\begingroup\$ It should be easy enough to learn quickly from experience how the photo would be exposed. Electronic viewfinder (like in Sony alpha SLT cameras) is well visible even in sunlight, and it does not have the effect that using live-view on an OVF DSLR does. \$\endgroup\$ Commented Mar 26, 2013 at 22:01

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It actually depends on the camera that you have. You basically have two kinds of "Live Preview", the first using an automatic gain fonction to help you with the framing. It's the most basic one and for this, no matter what exposure setting you choose or modify, the screen will keep showing the same scene.

The second type of live preview is called Real time exposure simulation live preview (name may vary depending on your camera make), where if you chance something (aperture, ISO or shutter speed) it will affect what you see on the LiveView screen.

I just made this simple test on my Canon EOS 1100D (which is very entry level)

  1. switch to manual, ISO100, f3.8, 1s
  2. switch to live view
  3. turn the main dial to modify shutter speed to 1/1000s: screen turned completely black.
  4. turn it the other way to modify shutter speed to 30s: screen turned completely white
  5. turn the dial to modify aperture and narrow it down to f12: screen went back to more or less properly exposed.

It is likely that you either are using a camera that did not feature this capability yet, or where it is disabled via menu.

Or you are shooting in a semi-auto mode (Aperture Priority, Shutter Priority) where the camera adjusts the other exposition settings for you as you change your settings so that the end image still stays properly exposed.

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  • \$\begingroup\$ This simulates the exposure effect for shutter-speed, yes, but it does not simulate the motion-blur from it and is normally called Exposure-Priority. \$\endgroup\$
    – Itai
    Commented Mar 26, 2013 at 19:35
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    \$\begingroup\$ The exposure simulation is what he is looking for. He clarified this with a later comment. \$\endgroup\$
    – Michael C
    Commented Mar 26, 2013 at 21:37
  • \$\begingroup\$ Two hours after my comment.... can't know the future but the entire question text is misleading considering the comment. He might as well have said previewed ISO to name another random parameter! \$\endgroup\$
    – Itai
    Commented Mar 26, 2013 at 22:39
  • \$\begingroup\$ @Itai you are supposed to be able to read minds and foresee the future (isn't there a badge for that?). Your "two hours after my comment" comment is therefore invalid :). \$\endgroup\$ Commented Mar 27, 2013 at 9:22
  • \$\begingroup\$ @Itai: That's what I meant by later. Later than your comment. ;-) \$\endgroup\$
    – Michael C
    Commented Mar 27, 2013 at 23:17
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Previewing exposure correctly should be most important but most DSLRs do not even get that right! The full effect of shutter-speed is rarely previewed but there is a good reason for that.

Better Live-View systems such as those by Canon and Sony, simulate the exposure by boosting the signal according to shutter-speed and aperture but still refresh the display at a reasonable speed, usually between 15 and 60 Hz. This means that the brightness you see takes into account shutter-speed but not motion in the scene.

Simulating the motion from shutter-speed is very difficult, not accurate and increases the latency of the display. Anything faster than the read-out speed is impossible to simulate because the camera reads the sensor at a certain-speed and anything slower requires to accumulate the signal over the shutter-speed duration. If you would instead expose for the duration of the shutter-speed, it would be much worse even.

You can actually see this work on some Panasonic mirrorless cameras and makes it very difficult to use because the display becomes unresponsive. It happens because what is shown on the display depends on several or even hundreds of prior frames.

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The Canon 5D Mark iii does take in to account Exposure simulation when in LiveView if you have the setting turned on. Shutter is one of the factors of exposure, but not the only one. I don't think it is turned on by default though. It is possible that other cameras also have it and simply require turning it on. I can't think of any particular reason why a DSLR wouldn't bother having it. They need to be able to approximate the settings for doing proper metering and exposure adjustments.

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