circle.html

<div class="filter-img">
  <div class="circle multiply"></div>
  <img src="img/backpack-lake.jpg">
</div>

<style>
.filter-img {
	position: relative;
	width: 100%;
	height: 100%;
}

.circle {
	position: absolute;
	top: 17.5%;
	left: 17.5%;
	vertical-align: middle;
	display: block;
	width: 65%;
	height: 65%;
	background-color: #3AC9F5;
	border-radius: 25em;
	background-blend-mode: screen;
}
</style>