# Viewport brightness/contrast adjustments broken in Big Sur?

**URL:** <https://discourse.slicer.org/t/viewport-brightness-contrast-adjustments-broken-in-big-sur/14678>\
**Category:** Support\
**Created:** [November 18, 2020, 8:36pm UTC](https://discourse.slicer.org/t/viewport-brightness-contrast-adjustments-broken-in-big-sur/14678 "2020-11-18T20:36:01Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![pll\_llq](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pll_llq/32/9408_2.png) [@pll\_llq](https://discourse.slicer.org/u/pll_llq)\
**Post date:** [November 18, 2020, 8:36pm UTC](https://discourse.slicer.org/t/viewport-brightness-contrast-adjustments-broken-in-big-sur/14678/1 "2020-11-18T20:36:01Z")

</div>

Hi there,

After the Big Sur update on my Mac I noticed that clicking and dragging over viewport windows with slices does not change the image brightness/contrast as it used to.

Is this a bug or did I miss a migration of this feature to the Volumes tab?

---

<div class="post-metadata">

**Author:** ![muratmaga](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/muratmaga/32/3622_2.png) [@muratmaga](https://discourse.slicer.org/u/muratmaga)\
**Post date:** [November 18, 2020, 8:40pm UTC](https://discourse.slicer.org/t/viewport-brightness-contrast-adjustments-broken-in-big-sur/14678/2 "2020-11-18T20:40:10Z")

</div>

Did you also upgrade your Slicer version too? For a while now you need to use the window/level mode mouse mode (see below).

> **[User Interface — 3D Slicer documentation](https://slicer.readthedocs.io/en/latest/user_guide/user_interface.html#mouse-modes)**

---

<div class="post-metadata">

**Author:** ![pll\_llq](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pll_llq/32/9408_2.png) [@pll\_llq](https://discourse.slicer.org/u/pll_llq)\
**Post date:** [November 18, 2020, 9:06pm UTC](https://discourse.slicer.org/t/viewport-brightness-contrast-adjustments-broken-in-big-sur/14678/3 "2020-11-18T21:06:26Z")

</div>

Hi, thanks for the link.  
My Slicer version is 4.11.20200930  
With the mouse mode selected

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/f/1/f1b435c6aa3503417e8d316e69798c3c281f7033.jpeg)  
Ctrl+click’n’drag zooms the image and Cmd+click’n’drag and simple click’n’drag do nothing

---

<div class="post-metadata">

**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [November 18, 2020, 9:10pm UTC](https://discourse.slicer.org/t/viewport-brightness-contrast-adjustments-broken-in-big-sur/14678/4 "2020-11-18T21:10:15Z")

</div>

You need to click “Adjust window/level” button on the toolbar - see [https://slicer.readthedocs.io/en/latest/user\_guide/user\_interface.html#adjusting-image-window-level](https://slicer.readthedocs.io/en/latest/user_guide/user_interface.html#adjusting-image-window-level)

---

<div class="post-metadata">

**Author:** ![pll\_llq](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pll_llq/32/9408_2.png) [@pll\_llq](https://discourse.slicer.org/u/pll_llq)\
**Post date:** [November 18, 2020, 9:12pm UTC](https://discourse.slicer.org/t/viewport-brightness-contrast-adjustments-broken-in-big-sur/14678/5 "2020-11-18T21:12:36Z")

</div>

Thanks! I definitely missed that.  
It used to be on by default