Review domain slider UI

Feedback below to be clarified:

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The contract scaling slider (3) was the only thing me and my users had some difficulties with:

a) Although the autoscale worked absolutely fine

b) Once you’ve messed up with the slider and set the wrong contract, the only way to go back to something reasonable is to click again on autoscale or to set the values manually.

I think the slider bar is simply maybe too small so it is difficult to fine tune the contrast scale?

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