diff --git a/Demo/ColorPickerTestApp/Base.lproj/MainMenu.xib b/Demo/ColorPickerTestApp/Base.lproj/MainMenu.xib
index 855f5a6..eff27a0 100644
--- a/Demo/ColorPickerTestApp/Base.lproj/MainMenu.xib
+++ b/Demo/ColorPickerTestApp/Base.lproj/MainMenu.xib
@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="21219" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES" customObjectInstantitationMethod="direct">
+<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="21701" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES" customObjectInstantitationMethod="direct">
     <dependencies>
         <deployment identifier="macosx"/>
-        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="21219"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="21701"/>
         <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
     </dependencies>
     <objects>
@@ -681,25 +681,25 @@
                     </menu>
                 </menuItem>
             </items>
-            <point key="canvasLocation" x="125" y="201"/>
+            <point key="canvasLocation" x="31" y="-278"/>
         </menu>
         <window title="ColorPickerTestApp" allowsToolTipsWhenApplicationIsInactive="NO" autorecalculatesKeyViewLoop="NO" releasedWhenClosed="NO" animationBehavior="default" id="QvC-M9-y7g">
             <windowStyleMask key="styleMask" titled="YES" closable="YES" miniaturizable="YES" resizable="YES"/>
             <windowPositionMask key="initialPositionMask" leftStrut="YES" rightStrut="YES" topStrut="YES" bottomStrut="YES"/>
-            <rect key="contentRect" x="335" y="390" width="313" height="133"/>
-            <rect key="screenRect" x="0.0" y="0.0" width="2560" height="1415"/>
+            <rect key="contentRect" x="335" y="390" width="577" height="365"/>
+            <rect key="screenRect" x="0.0" y="0.0" width="2048" height="1127"/>
             <view key="contentView" wantsLayer="YES" id="EiT-Mj-1SZ">
-                <rect key="frame" x="0.0" y="0.0" width="389" height="133"/>
-                <autoresizingMask key="autoresizingMask"/>
+                <rect key="frame" x="0.0" y="0.0" width="577" height="365"/>
+                <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                 <subviews>
                     <stackView distribution="fill" orientation="horizontal" alignment="centerY" spacing="30" horizontalStackHuggingPriority="249.99998474121094" verticalStackHuggingPriority="249.99998474121094" detachesHiddenViews="YES" translatesAutoresizingMaskIntoConstraints="NO" id="EL5-rt-E4v">
-                        <rect key="frame" x="20" y="25" width="277" height="88"/>
+                        <rect key="frame" x="20" y="25" width="465" height="320"/>
                         <subviews>
                             <stackView distribution="fill" orientation="vertical" alignment="leading" horizontalStackHuggingPriority="249.99998474121094" verticalStackHuggingPriority="249.99998474121094" detachesHiddenViews="YES" translatesAutoresizingMaskIntoConstraints="NO" id="GOi-FF-ova">
-                                <rect key="frame" x="0.0" y="20" width="86" height="48"/>
+                                <rect key="frame" x="0.0" y="136" width="149" height="48"/>
                                 <subviews>
                                     <button horizontalHuggingPriority="10" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="Z77-Fi-3wA">
-                                        <rect key="frame" x="-7" y="21" width="100" height="32"/>
+                                        <rect key="frame" x="-7" y="21" width="163" height="32"/>
                                         <buttonCell key="cell" type="push" title="Pick" bezelStyle="rounded" alignment="center" borderStyle="border" imageScaling="proportionallyDown" inset="2" id="dnI-5H-L7Z">
                                             <behavior key="behavior" pushIn="YES" lightByBackground="YES" lightByGray="YES"/>
                                             <font key="font" metaFont="system"/>
@@ -729,10 +729,10 @@
                                 </customSpacing>
                             </stackView>
                             <stackView distribution="fill" orientation="vertical" alignment="centerX" spacing="4" horizontalStackHuggingPriority="249.99998474121094" verticalStackHuggingPriority="249.99998474121094" detachesHiddenViews="YES" translatesAutoresizingMaskIntoConstraints="NO" id="8nt-lf-pnl">
-                                <rect key="frame" x="116" y="3" width="63" height="83"/>
+                                <rect key="frame" x="179" y="86" width="128" height="148"/>
                                 <subviews>
                                     <textField verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="CME-pR-pid">
-                                        <rect key="frame" x="14" y="67" width="35" height="16"/>
+                                        <rect key="frame" x="47" y="132" width="35" height="16"/>
                                         <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" sendsActionOnEndEditing="YES" title="color" id="y4x-rE-5dF">
                                             <font key="font" metaFont="system"/>
                                             <color key="textColor" name="controlTextColor" catalog="System" colorSpace="catalog"/>
@@ -740,10 +740,10 @@
                                         </textFieldCell>
                                     </textField>
                                     <colorWell translatesAutoresizingMaskIntoConstraints="NO" id="j1T-Wo-Me3">
-                                        <rect key="frame" x="0.0" y="0.0" width="63" height="63"/>
+                                        <rect key="frame" x="-3" y="-2" width="134" height="132"/>
                                         <constraints>
-                                            <constraint firstAttribute="height" constant="63" id="IGy-WL-uME"/>
-                                            <constraint firstAttribute="width" constant="63" id="gQE-1j-aO5"/>
+                                            <constraint firstAttribute="height" constant="128" id="IGy-WL-uME"/>
+                                            <constraint firstAttribute="width" constant="128" id="gQE-1j-aO5"/>
                                         </constraints>
                                         <color key="color" red="0.05813049898" green="0.055541899059999997" blue="1" alpha="1" colorSpace="calibratedRGB"/>
                                     </colorWell>
@@ -758,10 +758,10 @@
                                 </customSpacing>
                             </stackView>
                             <stackView distribution="fill" orientation="vertical" alignment="centerX" spacing="7" horizontalStackHuggingPriority="249.99998474121094" verticalStackHuggingPriority="249.99998474121094" detachesHiddenViews="YES" translatesAutoresizingMaskIntoConstraints="NO" id="fnx-WC-0PZ">
-                                <rect key="frame" x="209" y="4" width="68" height="81"/>
+                                <rect key="frame" x="337" y="85" width="128" height="151"/>
                                 <subviews>
                                     <textField verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="W4L-1n-B3x">
-                                        <rect key="frame" x="-2" y="65" width="72" height="16"/>
+                                        <rect key="frame" x="28" y="135" width="72" height="16"/>
                                         <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" sendsActionOnEndEditing="YES" title="screenshot" id="7SA-Mv-TIn">
                                             <font key="font" metaFont="system"/>
                                             <color key="textColor" name="controlTextColor" catalog="System" colorSpace="catalog"/>
@@ -769,10 +769,10 @@
                                         </textFieldCell>
                                     </textField>
                                     <imageView horizontalHuggingPriority="251" verticalHuggingPriority="251" translatesAutoresizingMaskIntoConstraints="NO" id="KUk-If-IdF" customClass="CustomImageView" customModule="ColorPickerTestApp" customModuleProvider="target">
-                                        <rect key="frame" x="3" y="-3" width="63" height="64"/>
+                                        <rect key="frame" x="-3" y="-3" width="134" height="134"/>
                                         <constraints>
-                                            <constraint firstAttribute="width" constant="57" id="SMq-ke-xB8"/>
-                                            <constraint firstAttribute="height" constant="58" id="fPX-Yo-5ZA"/>
+                                            <constraint firstAttribute="width" constant="128" id="SMq-ke-xB8"/>
+                                            <constraint firstAttribute="height" constant="128" id="fPX-Yo-5ZA"/>
                                         </constraints>
                                         <imageCell key="cell" refusesFirstResponder="YES" alignment="left" imageScaling="proportionallyDown" imageFrameStyle="grayBezel" id="Ax5-sL-Lie"/>
                                     </imageView>
@@ -806,7 +806,7 @@
                     <constraint firstAttribute="bottom" secondItem="EL5-rt-E4v" secondAttribute="bottom" constant="25" id="pHq-cj-ucG"/>
                 </constraints>
             </view>
-            <point key="canvasLocation" x="12.5" y="-44.5"/>
+            <point key="canvasLocation" x="43.5" y="39.5"/>
         </window>
     </objects>
 </document>
diff --git a/Sources/DSFColorSampler/DSFColorSampler.swift b/Sources/DSFColorSampler/DSFColorSampler.swift
index a0622b4..4094f24 100644
--- a/Sources/DSFColorSampler/DSFColorSampler.swift
+++ b/Sources/DSFColorSampler/DSFColorSampler.swift
@@ -63,6 +63,9 @@ import Cocoa
 	/// Color and location selection block callback. If the user cancels the selection (pressed ESC) then selectedColor will be nil
 	public typealias LocationChangedBlock = (_ currentImage: NSImage, NSColor) -> Void
 
+	fileprivate static let pixelMaxZoom: CGFloat = 7
+	fileprivate static let pixelMinZoom: CGFloat = 1
+	
 	/// Display the color selector and allow the user to select a color
 	///
 	/// - Parameters:
@@ -145,8 +148,9 @@ private extension DSFColorSampler {
 	}
 
 	func run() {
+		let size = pow(2, DSFColorSampler.pixelMaxZoom)
 		self.screenPickerWindow = DSFColorSamplerWindow(
-			contentRect: NSRect(x: 0, y: 0, width: 125, height: 125),
+			contentRect: NSRect(x: 0, y: 0, width: size, height: size),
 			styleMask: .borderless,
 			backing: .buffered,
 			defer: true
@@ -220,7 +224,7 @@ private protocol DSFColorSamplerDelegate: NSWindowDelegate {
 }
 
 private class DSFColorSamplerWindow: NSWindow {
-	private var pixelZoom: CGFloat = 7
+	private var pixelZoom: CGFloat = 2
 
 	var _image: CGImage?
 
@@ -251,7 +255,7 @@ private class DSFColorSamplerWindow: NSWindow {
 
 	override open func mouseMoved(with event: NSEvent) {
 		let point = NSEvent.mouseLocation
-		let captureSize: CGFloat = self.frame.size.width / self.pixelZoom
+		let captureSize = self.frame.size.width / pow(2, self.pixelZoom - 1) + 1
 		guard
 			// screen where mouse resides
 			let screenWithMouse = NSScreen.screens.first(where: { NSMouseInRect(point, $0.frame, false) }),
@@ -325,7 +329,7 @@ private class DSFColorSamplerWindow: NSWindow {
 		else if event.deltaY < -0.01 {
 			self.pixelZoom -= 1
 		}
-		self.pixelZoom = self.pixelZoom.clamped(to: 2 ... 24)
+		self.pixelZoom = self.pixelZoom.clamped(to: DSFColorSampler.pixelMinZoom ... DSFColorSampler.pixelMaxZoom)
 
 		(self.contentView as? DSFColorSamplerView)?.pixelZoom = self.pixelZoom
 
@@ -348,7 +352,7 @@ private class DSFColorSamplerWindow: NSWindow {
 // MARK: - DSFColorSamplerView
 
 private class DSFColorSamplerView: NSView {
-	var pixelZoom: CGFloat = 7
+	var pixelZoom: CGFloat = 2
 	var _image: CGImage?
 
 	// Wrapper to work around lack of cgContext on 10.9
@@ -389,7 +393,7 @@ private class DSFColorSamplerView: NSView {
 		}
 
 		// draw the aperture
-		let apertureSize: CGFloat = self.pixelZoom
+		let apertureSize: CGFloat = width / (pow(2, DSFColorSampler.pixelMaxZoom - self.pixelZoom + 1) + 1)
 		let x: CGFloat = (width / 2.0) - (apertureSize / 2.0)
 		let y: CGFloat = (height / 2.0) - (apertureSize / 2.0)