How to Expand the ISO Range on Your Canon EOS 6D - dummies

How to Expand the ISO Range on Your Canon EOS 6D

By Doug Sahlin

You can extend the ISO range of your Canon EOS 6D to give you a range from ISO 50 to ISO 102400. The extended ISO range will definitely enable you to capture images in very dim lighting conditions, but there is a payback in the form of some pretty gnarly digital noise.

On the low end of the spectrum, ISO 50, you’ll be able to shoot at slower shutter speeds, which is a definite bonus when you photograph beautiful waterfalls. To extend the ISO range of your camera:

  1. Press the Menu button.

    The last-used menu command is displayed.

  2. Use the Multi-controller to navigate to the Shooting Settings 3 tab and then use the Multi-controller or the Quick Control dial to highlight ISO Speed Settings.

  3. Press Set.

    The ISO Speed Settings options are displayed. Note that you can manually set the ISO using the first menu command. Although, it’s easy to question the wisdom of that command when you can quickly set the ISO using a button and dial. (Perhaps that command exists for gluttons for punishment who have used menu-concentric cameras in the past. You know who you are.)


  4. Use the Multi-controller or Quick Control dial to highlight ISO Speed Range and then press Set.

    The Minimum ISO setting box is highlighted.

  5. Press Set.

    An arrow appears above and below the current minimum setting. That’s right, if you wanted to, you could increase the minimum setting. You always get the best-quality images shooting with the lowest possible ISO setting.

  6. Use the Multi-controller to select 50.

    A dialog box appears, showing you that the ISO setting of 50 will appear as L when you select it. You’re also warned that the low ISO setting will be bumped to 100 when you capture video.

  7. Press Set.

    The change is applied. If you only want to change the minimum ISO setting go to Step 10.

  8. Use the Multi-controller right to highlight the current maximum ISO setting and then press Set.

    An arrow appears above and below the current maximum ISO setting. If you’re not happy with the results you’re getting at the current maximum ISO settings, press the Multi-controller down to select a lower maximum ISO setting.

  9. To increase the maximum ISO setting, press the top of the Multi-controller once to select H1(102400) and a second time to select H2(512400). After highlighting the desired setting, press Set.

    The change is applied.

  10. Use the Multi-controller highlight OK and then press Set.

    The changes are applied and the ISO settings you have to work with have been extended.


In addition to expanding the ISO range, you can specify the Auto ISO Range by choosing that command from the ISO menu. If you use Auto ISO, you may find it useful to specify the minimum and maximum ISO that can be used when you let the camera automatically choose the ISO setting.

Another option you may find useful is setting the minimum shutter speed that will be used when Auto ISO is in effect. This prevents using an ISO that would result in a slow shutter speed, potentially causing a blurred picture. This option is set to Auto by default, however, you can modify it by choosing Min Shutter Spd under the ISO Speed Settings menu.